4 Antibiotic resistance in animals
4.1 Notifiable diseases
In Sweden, findings of carbapenemase-producing Enterobacterales (ESBLCARBA) and methicillin-resistant coagulase-positive staphylococci in animals are notifiable (SJVFS 2021:10 and previously SJVFS 2012:24 with amendments). In the monitoring, the attention regarding methicillin-resistant coagulase-positive staphylococci is mainly directed towards methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus pseudintermedius (MRSP). Furthermore, as Enterobacterales producing classical ESBLs (ESBLA) or plasmid-mediated AmpC (ESBLM) as well as vancomycin resistant enterococci (VRE) are notifiable when detected in humans, specific attention is also paid to these bacteria in animals.
4.1.1 ESBL-producing Enterobacterales
Healthy farm animals
Escherichia coli
In Sweden, ESBLCARBA in animals are notifiable but not ESBLA or ESBLM. In 2025, various samples from healthy farm animals were screened for Escherichia coli resistant to ESCs and carbapenems using selective media. Isolates with reduced susceptibility were further investigated by genome sequencing for presence of transferable genes coding for ESC resistance (for details see Chapter 6 - Material and methods, Resistance in bacteria from animals).
Active screening for E. coli resistant to ESCs in healthy farm animals using faecal samples collected at slaughter has been performed since 2008. The proportions of samples positive for E. coli with ESBLA or ESBLM in screenings of healthy animals are available as Supplementary material on the SVA web page.
Fattening pigs
Samples from fattening pigs were collected at slaughter under the supervision of the National Food Agency (SLV) at six abattoirs that together processed more than 85% of the total number of pigs slaughtered in Sweden 2025. The number of samples from each abattoir was roughly proportional to the annual slaughter volume of the abattoir. Each sample was randomly selected but represented a unique herd per day. Samples were kept refrigerated until they were sent to SVA for culture the same day or the day after collecting.
Carbapenem-resistant E. coli was not isolated from any of the 301 investigated samples.
Escherichia coli with ESC resistance was isolated from six (2%) of the 301 investigated samples and a transferable gene coding for ESC resistance was detected in five isolates, i.e. 2% of the samples (Table 4.1). All five isolates with a transferable gene had an ESBLA phenotype and carried blaCTX-M-15 (n=2), blaCTX-M-14 (n=1), blaCTX-M-55 (n=1) and blaSHV-12 (n=1). The remaining isolate with ESC-resistance had an AmpC phenotype and genome sequencing revealed a mutation causing hyper-production of AmpC beta-lactamases, i.e. a shift from C to T at position 42 of the ampC promoter.
All the isolates with transferable ESC-resistance were also resistant to ciprofloxacin and tetracycline. Furthermore, resistance to sulphamethoxazole and trimethoprim were detected in four isolates each, resistance to azithromycin and chloramphenicol were detected in two isolates each and resistance to gentamicin was detected in one isolate.
The proportion of samples with ESC-resistant E. coli (2%) is comparable to 2023 (3%) but lower than in previous years (8% in 2021 and 12-13% in 2015-2019). The reason(s) for this change is not known. The proportion of samples with transferable ESC resistance has always been lower and hence the difference is less visible for this subset.
Broilers
Samples from broilers were randomly selected among caeca collected at slaughter within the Swedish Campylobacter programme, in which whole caeca are collected from each batch of broilers slaughtered. From these samples, 50 were selected in April-May and 50 in October-December. Each sample was from a unique flock but not always from a unique production site. The cultured samples were collected at seven abattoirs that in 2025 accounted for approximately 98% of the total volume of broilers slaughtered. The number of samples from each abattoir was roughly proportional to the annual slaughter volume of the abattoir and the sampling was distributed over the year.
Carbapenem-resistant E. coli was not isolated from any of the 100 investigated samples.
Escherichia coli with ESC-resistance was not isolated from any of the 100 investigated samples (Table 4.1). This is the first time since selective methods to detect E. coli with ESC-resistance among broilers was introduced in the Svarm monitoring in 2010 that all samples were negative. However, only a limited number of samples were investigated in 2025, and it is uncertain if the situation will remain when a larger number of samples are investigated in 2026.
Due to differences in methodology over the years, changes in the proportion of positive samples over the whole time period cannot be directly assessed. However, some comparison with earlier years is possible, as the samples from 2015 and the first half of 2016 as well as the samples from 2021 were cultured in duplicate with both methods that were relevant for the respective years (for details on methodology see Chapter 6 - Material and methods, Resistance in bacteria from animals in current or previous Swedres-Svarm reports). The difference in the proportion of broiler caecal samples positive for E. coli with ESBLA or ESBLM since 2016 is statistically significant (p<0.01, X2; Figure 4.1). This decrease is most likely explained by decreased occurrence of such bacteria in the breeding pyramid (Nilsson et al. 2020).
Meat samples
Escherichia coli
In Sweden, neither carbapenemase-producing Enterobacterales (ESBLCARBA), nor classical ESBLs (ESBLA) or plasmid-mediated AmpC (ESBLM) are notifiable in food. Active screening for Escherichia coli resistant to ESCs in meat samples collected at retail has been performed since 2008. During 2025, pig and cattle meat samples were screened for E. coli resistant to ESCs and carbapenems using selective media (for details see Chapter 6 - Material and methods, Resistance in bacteria from animals).
Samples from pig and cattle meat were collected at retail by municipal environmental departments in nine different municipalities in Sweden. The samples were distributed throughout the year and among the municipalities in order to get a representative sampling. Furthermore, consignments of pig and cattle meat from countries outside EU imported via border control posts in Sweden were sampled by personnel from the National Food Agency (SLV).
The proportions of samples positive for E. coli with ESBLA or ESBLM in screenings of meat sampled at retail are available as Supplementary material on the SVA web page.
Pig meat
A total of 300 samples of fresh pig meat were collected at retail. The samples comprised meat originating both from Sweden (n=277) and other EU countries (n=23).
Escherichia coli with carbapenem resistance was not isolated from any of the samples of pig meat collected at retail.
Escherichia coli with ESC-resistance was isolated from one (<1%) of 300 investigated samples (Table 4.1). The sample was of Swedish origin, and the isolate had an ESBLM phenotype and carried blaDHA-1.
In addition, one consignment of pig meat from a country outside EU was sampled at border control post. From this consignment, three samples were analysed.
Escherichia coli with carbapenem resistance or ESC-resistance were not isolated from any of the samples of pig meat collected at border control post.
Cattle meat
A total of 300 samples of fresh cattle meat were collected at retail. The samples comprised of meat originating both from Sweden (n=274), other EU countries (n=21) and from outside EU (n=5).
Escherichia coli with carbapenem resistance was not isolated from any of the samples of cattle meat collected at retail.
Escherichia coli with ESC-resistance was isolated from one (<1%) of 300 investigated samples (Table 4.1). The sample was of non-Swedish origin, and the isolate had an ESBLA phenotype and carried blaCTX-M-27.
In addition, four consignments of cattle meat from countries outside EU were sampled at border control posts. From these consignments, nine samples were analysed.
Escherichia coli with carbapenem resistance or ESC-resistance were not isolated from any of the samples of cattle meat collected at border control posts.
| Origin and year | Broilers (2025) | Cattle (2023-24) | Laying hens (2022) | Pigs (2025) | Turkey (2024) | Broiler meat (2024) | Cattle meat (2025) | Pig meat (2025) | Turkey meat (2024) |
|---|---|---|---|---|---|---|---|---|---|
| Swedish | 0 | 0 | 2 | 2 | 0 | <1 | 0 | <1 | 0 |
| Non-Swedish | – | – | – | – | – | 40 | 4 | 0 | – |
Clinical isolates from companion animals and horses
In Svarm, there are no recurring active screenings for ESBL-producing Enterobacterales in healthy companion animals or horses. However, results of the screenings for ESC resistant E. coli that have been performed are available as Supplementary material on the SVA web page.
For a number of years, funding from the Swedish Board of Agriculture has enabled SVA to perform confirmation of suspected ESC-resistance in clinical isolates of Enterobacterales free of charge for referring laboratories. During 2025, 38 submitted isolates of Enterobacterales with phenotypic resistance to ESCs from companion animals and horses were confirmed to produce ESBLA and/or ESBLM by genome sequencing (Table 4.2). The isolates were from cats (n=6), dogs (n=14) and horses (n=18). The majority of the isolates from cats and dogs were E. coli and the most common gene was blaCTX-M-15. For horses, the majority of the isolates belonged to the Enterobacter sp. cloacae complex and the most common gene was blaSHV-12. Data regarding clinical isolates from cats, dogs and horses confirmed to produce ESBLA and/or ESBLM is available as Supplementary material on the SVA web page.
About three quarters of the investigated isolates were resistant to at least two antibiotics besides beta-lactams, i.e. multiresistant. The most common resistances were against trimethoprim-sulphonamides (65%) and gentamicin (54%). Resistance to quinolones and tetracycline were also common traits. For the years 2021-2025 the occurrence of resistance to quinolones was higher among isolates from companion animals than among isolates from horses. On the contrary, the occurrence of resistance to gentamicin and trimethoprim-sulphonamides was higher among isolates from horses than among isolates from companion animals (Table 4.3).
| Animal species | Beta-lactamase group | Beta-lactamase gene | Bacterial species | No. of isolates |
|---|---|---|---|---|
| Cat | CTX-M-1 | CTX-M-1 | Escherichia coli | 1 |
| Cat | CTX-M-1 | CTX-M-15 | Escherichia coli | 2 |
| Cat | CTX-M-1 | CTX-M-15 | Klebsiella pneumoniae | 1 |
| Cat | CTX-M-9 | CTX-M-14 | Escherichia coli | 1 |
| Cat | CTX-M-9 | CTX-M-27 | Escherichia coli | 1 |
| Dog | CIT | CMY-2 | Escherichia coli | 2 |
| Dog | CIT | CMY-2 | Proteus mirabilis | 1 |
| Dog | CIT + CTX-M-1 | CMY-2 + CTX-M-1 | Escherichia coli | 1 |
| Dog | CTX-M-1 | CTX-M-15 | Escherichia coli | 9 |
| Dog | CTX-M-1 | CTX-M-15 | Klebsiella pneumoniae | 1 |
| Horse | CTX-M-1 | CTX-M-1 | Enterobacter cloacae complex | 1 |
| Horse | CTX-M-1 | CTX-M-1 | Klebsiella species | 1 |
| Horse | CTX-M-1 | CTX-M-15 | Klebsiella pneumoniae | 1 |
| Horse | DHA | DHA-like | Klebsiella species | 1 |
| Horse | DHA + SHV | DHA-1 + SHV-12 | Enterobacter species | 1 |
| Horse | SHV | SHV-12 | Enterobacter species | 1 |
| Horse | SHV | SHV-12 | Enterobacter cloacae complex | 3 |
| Horse | SHV | SHV-12 | Enterobacter hormaechei | 1 |
| Horse | SHV | SHV-12 | Escherichia coli | 2 |
| Horse | SHV | SHV-12 | Klebsiella species | 1 |
| Horse | SHV | SHV-12 | Klebsiella aerogenes | 3 |
| Horse | SHV | SHV-12 | Klebsiella oxytoca | 1 |
| Horse | SHV | SHV-12 | Leclercia species | 1 |
| Antibiotic | ECOFF (mg/L) | Dogs and cats (n=85) Resistance (%) | Horses (n=115) Resistance (%) |
|---|---|---|---|
| Enrofloxacin | 0.12 | 53 | 28 |
| Gentamicin | 2 | 26 | 87 |
| Neomycin | 8 | 7 | 29 |
| Tetracycline | 8 | 34 | 25 |
| Trim-Sulph. | 0.5 | 49 | 84 |
4.1.2 Methicillin-resistant Staphylococcus aureus (MRSA)
In Sweden, methicillin-resistant Staphylococcus aureus (MRSA) in animals was first verified in 2006 and made notifiable in 2008 (SJVFS 2021:10 and previous legislation). Since then, most cases in domesticated animals have been detected in passive monitoring of clinical sampling in infected animals. Isolates of S. aureus with resistance to oxacillin or cefoxitin have been further analysed with confirmatory tests. Screening studies for active monitoring have been performed in pigs, cattle, horses, dogs and hedgehogs during different years (see below). Cases from 2025 are presented in Table 4.4 and data regarding index cases of clinical isolates and isolates from screenings are shown as Supplementary material on the SVA web page.
| Animal species | Beta-lactams | Cli | Ery | Tet | Fus | Gen | Cip | Tmp | Chl | Lzd | spa-type | mec-gene |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cat | R | 0.25 | 0.5 | ≤0.5 | ≤0.25 | ≤0.5 | ≤0.25 | ≤1 | 8 | 2 | t304 | A |
| Cat | R | ≤0.12 | >8 | >16 | ≤0.25 | ≤0.5 | ≤0.25 | ≤1 | ≤4 | ≤1 | t127 | A |
| Cat | R | ≤0.12 | >8 | ≤0.5 | 4 | ≤0.5 | 0.5 | ≤1 | 8 | ≤1 | t4549 | A |
| Cat | R | ≤0.12 | 0.5 | ≤0.5 | ≤0.25 | ≤0.5 | 0.5 | ≤1 | 8 | 2 | t978 | C |
| Cat | R | ≤0.12 | ≤0.25 | 1 | ≤0.25 | 1 | 0.5 | 2 | 8 | 2 | t267 | A |
| Cat | R | ≤0.12 | ≤0.25 | ≤0.5 | ≤0.25 | ≤0.5 | 0.5 | ≤1 | 8 | 2 | t11940 | A |
| Cat | R | ≤0.12 | ≤0.25 | ≤0.5 | ≤0.25 | ≤0.5 | ≤0.25 | ≤1 | ≤4 | ≤1 | t12236 | A |
| Dog | R | >4 | 0.5 | >16 | ≤0.25 | ≤0.5 | >8 | >16 | 8 | 1
|
t034 | A |
| Dog | R | >4 | 0.5 | >16 | ≤0.25 | ≤0.5 | >8 | ≤1 | 8 | 2 | t011 | A |
| Dog | R | >4 | 0.5 | >16 | ≤0.25 | ≤0.5 | 8 | >16 | ≤4 | ≤1 | t034 | A |
| Dog | R | ≤0.12 | 0.5 | ≤0.5 | ≤0.25 | ≤0.5 | 0.5 | ≤1 | ≤4 | ≤1 | t373 | C |
| Dog | R | ≤0.12 | 0.5 | ≤0.5 | ≤0.25 | ≤0.5 | ≤0.25 | ≤1 | 8 | 2 | t304 | A |
| Dog | R | ≤0.12 | 0.5 | ≤0.5 | ≤0.25 | ≤0.5 | ≤0.25 | ≤1 | ≤4 | ≤1 | t9975 | A |
| Dog | R | ≤0.12 | ≤0.25 | ≤0.5 | ≤0.25 | ≤0.5 | 0.5 | >16 | 8 | 2 | t9053 | A |
| Dog | R | ≤0.12 | ≤0.25 | ≤0.5 | ≤0.25 | ≤0.5 | 0.5 | >16 | ≤4 | ≤1 | t223 | A |
| Dog | R | ≤0.12 | ≤0.25 | ≤0.5 | ≤0.25 | ≤0.5 | 0.5 | ≤1 | 8 | ≤1 | t843 | C |
| Dog | R | ≤0.12 | ≤0.25 | ≤0.5 | ≤0.25 | ≤0.5 | 0.5 | ≤1 | ≤4 | ≤1 | t051 | A |
| Horse | R | ≤0.12 | >8 | >16 | ≤0.25 | >16 | 0.5 | >16 | ≤4 | ≤1 | t1451 | A |
| Horse | R | ≤0.12 | 0.5 | >16 | ≤0.25 | >16 | >8 | >16 | 8 | 2 | t011 | A |
| Horse | R | ≤0.12 | 0.5 | >16 | ≤0.25 | >16 | 0.5 | >16 | 8 | 2 | t011 | A |
| Horse | R | ≤0.12 | 0.5 | >16 | ≤0.25 | >16 | 0.5 | >16 | 8 | ≤1 | t011 | A |
| Horse | R | ≤0.12 | ≤0.25 | >16 | ≤0.25 | >16 | 0.5 | >16 | 8 | 2 | t011 | A |
| Horse | R | ≤0.12 | ≤0.25 | >16 | ≤0.25 | >16 | ≤0.25 | >16 | 8 | ≤1 | t011 | A |
| Horse | R | ≤0.12 | ≤0.25 | >16 | ≤0.25 | 16 | >8 | >16 | ≤4 | ≤1 | t1257 | A |
| Hedgehog | R | ≤0.12 | ≤0.25 | ≤0.5 | ≤0.25 | ≤0.5 | 0.5 | ≤1 | ≤4 | ≤1 | t21515 | C |
| Pigs t011 (n=7) | R | >4 | ≤0.25 - >8 | >16 | ≤0.25 | ≤0.5 - 1 | ≤0.25 - 0.5 | ≤1 - >16 | 8 - 16 | ≤1 - 2 | t011 | A |
| Pigs t034 (n=50) | R | ≤0.12 - >4 | ≤0.25 - >8 | 16 - >16 | ≤0.25 - 2 | ≤0.5 - 8 | ≤0.25 - 2 | >16 | ≤4 - >64 | ≤1 - 2 | t034 | A |
| Pigs t571 (n=3) | R | ≤0.12 - 4 | ≤0.25 - 0.5 | >16 | ≤0.25 | ≤0.5 | ≤0.25 - 0.5 | >16 | 8 - 64 | ≤1 - 2 | t571 | A |
Farm animals
Screening studies in pigs have been performed five times since 2006, with two positive samples from pigs at slaughter in 2010. A screening was performed in all 39 nucleus and multiplying herds present in 2014, and all samples were negative. In 2025, an EU-wide baseline study on the prevalence of MRSA in pigs at slaughterhouses was performed. MRSA was detected in 60 (29%) of investigated slaughter groups. All the investigated isolates carried mecA and belonged to CC398. Spa-type t034 was most common (n=50), followed by t011 (n=7) and a few t571 (n=3). How well this reflects the occurrence on farm is not known but sampling of farms with piglets is being performed in 2025/2026.
In dairy cattle, active monitoring of selected isolates of beta-lactamase-producing S. aureus from milk samples has been ongoing since 2010, and about 1 540 isolates have been tested up to and including 2025. The monitoring is performed on isolates with anonymised origin. Since 2010, five PVL-negative isolates with mecC, two PVL-negative isolates with mecA and one PVL-positive isolate with mecA have been detected. In 2012, PVL-positive MRSA with mecA was isolated from several animals in a dairy herd (Unnerstad et al. 2018). In 2025, no MRSA was detected among the 44 isolates screened for occurrence of mecA and mecC.
In 2016 and early 2017, there was an outbreak of MRSA with mecC among goats and sheep connected to a zoo. In addition, MRSA with mecC was found in eight out of 21 sampled goats in a herd in 2017 and in one goat sold from the same herd. In 2019, an additional goat herd with MRSA was identified. The farm had an epidemiological link to the herd detected in 2017 and shared the same spa-type, t373. In total, six goats were sampled, and samples were pooled two and two for cultivation, with all pools being positive for mecC-MRSA. In 2019, 22 dairy goat herds were screened for occurrence of MRSA using bulk-milk samples and pooled swabs, with no positive samples found (Persson et al. 2021).
Companion animals and horses
Up to and including 2025, a total of 309 cases of MRSA in companion animals and horses have been confirmed. These include 91 dogs, 66 cats, four rabbits, one parrot and 144 horses. In these animal species, there is currently no regular active monitoring of MRSA, but screenings in dogs were performed in 2006, 2012 and 2017-2018 without detection of MRSA (Börjesson et al. 2020). Screening studies in horses have been performed twice, in 2007 and 2010, with one positive sample in 2007.
In 2025, MRSA was detected in clinical samples from wound infections and abscesses in ten dogs and six cats (Table 4.4). During the years the identified spa-types have varied, and most have previously been detected in humans. In 2025, one dog carried the horse-related t011 and two dogs carried the livestock-associated t034 (Supplementary material on the SVA web page, Table 4.4).
In 2025, MRSA was isolated from seven horses, which is fewer cases compared to 2020-2024, and the number of cases is back to the level during the years 2007-2019 when between one and nine cases were notified per year (Supplementary material on the SVA web page, Table 4.4). In 2020 and 2021, the increase was partly explained by outbreaks of MRSA in equine hospitals (spa-type t1971, t034 and t011). Historically, MRSA spa-type t011 has been dominating among horses in Sweden and in 2025, the spa-type was detected in five of the seven cases. The remaining two MRSA isolates were one each of spa-types t1257 and t1451 (Table 4.4). All the mentioned spa-types have also been detected more or less frequently in MRSA from humans.
Wild animals
High occurrence of mecC-MRSA has been described in hedgehogs in Sweden (64%) and Denmark (61%) (Bengtsson et al. 2017; Rasmussen et al. 2019), as well as in other countries. Recent studies suggest that mecC-MRSA probably originates from hedgehogs and as the result of selective pressure from beta-lactams produced by dermatophytes, and that this occurred long before the introduction of clinically used antibiotics (Larsen et al. 2022).
4.1.3 Methicillin-resistant Staphylococcus pseudintermedius (MRSP)
In 2025, there were 45 MRSP cases from 43 dogs, one cat and one guinea pig reported to the Swedish Board of Agriculture. This number is roughly the same level as in previous years (Figure 4.2).
All isolates but one were available for further susceptibility testing and genome sequencing. Information on the sampling site was available for 36 cases; wounds 13 cases, skin nine cases, external ear canal six cases, urine three cases and the remaining five cases were isolated from various other sites. For resistance phenotypes, see Table 4.5.
The results of the genome sequencing of 44 isolates, divided the isolates into 22 different multi-locus sequence types, of which ST551 was the most common type with 19 isolates. The ST551 was first detected in Sweden in 2016 and was also the most common ST in the last seven years. The other sequence types occurring in 2025 were three isolates with ST496, two isolates each with ST258 and ST1095, and single isolates of ST155, ST535, ST690, ST727, ST826, ST1054, ST1055, ST1832, ST2636, ST2684, ST2685, ST2859, ST2962 as well as five new STs, named ST3049-3053. In earlier years, ST71 dominated among Swedish isolates but no isolate of this type was found in 2024 or 2025.
| Beta-lactams | Tet | Sxt | Ery | Cli | Gen | Enr | Fus | Nit | No. of isolates |
|---|---|---|---|---|---|---|---|---|---|
| R | >4 | 0.5/9.5 - >4/76 | >2 | >2 | 2 - >4 | 1 - >1 | ≤0.25 - 0.5 | ≤16 | 29 |
| R | >4 | >4/76 | >2 | >2 | >4 | ≤0.25 | ≤0.25 | ≤16 | 2 |
| R | >4 | 0.5/9.5 | >2 | >2 | ≤1 | 1 | ≤0.25 | 32 | 1 |
| R | >4 | 0.5/9.5 - >4/76 | >2 | 1 - >2 | ≤1 | ≤0.25 | ≤0.25 | ≤16 | 2 |
| R | >4 | >4/76 | >2 | 0.5 | >4 | ≤0.25 | 0.5 | ≤16 | 1 |
| R | >4 | >4/76 | ≤0.25 | R | >4 | >1 | ≤0.25 | ≤16 | 1 |
| R | >4 | >4/76 | 0.5 | ≤0.25 | >4 | >1 | 0.5 | ≤16 | 1 |
| R | >4 | 0.5/9.5 | ≤0.25 | ≤0.25 | 4 | ≤0.25 | ≤0.25 | ≤16 | 1 |
| R | >4 | ≤0.25/4.75 | >2 | >2 | 4 | >1 | ≤0.25 | ≤16 | 1 |
| R | >4 | ≤0.25 | ≤0.25 | ≤0.25 | >4 | >1 | ≤0.25 | ≤16 | 1 |
| R | ≤0.25 | >4/76 | >2 | 1 | ≤1 | ≤0.25 | ≤0.25 | ≤16 | 1 |
| R | ≤0.25 | 0.5/9.5 | ≤0.25 | ≤0.25 | >4 | 0.5 | ≤0.25 | ≤16 | 1 |
| R | ≤0.25 | 0.5/9.5 | ≤0.25 | ≤0.25 | ≤1 | ≤0.25 | ≤0.25 | ≤16 | 1 |
| R | ≤0.25 | ≤0.25/4.75 | ≤0.25 | ≤0.25 | ≤1 | ≤0.25 | ≤0.25 | ≤16 | 1 |
4.2 Zoonotic pathogens
Zoonoses are diseases that can be naturally transmitted between animals and humans. Antibiotic resistance in zoonotic bacteria such as Salmonella and Campylobacter from animals is therefore of direct public health concern.
4.2.1 Salmonella
Findings of Salmonella in animals are notifiable in Sweden. In Svarm, antibiotic susceptibility is determined in one isolate from each notified incident in animals each year, except for wild birds and cats (see below). Isolates from incidents previously notified but still under restrictions are also included. In incidents involving more than one serovar, one isolate of each serovar is tested. In the case of poultry, one isolate from each infected flock is included.
Isolates from wild birds are usually from cases of salmonellosis among passerines during the winter season and most Salmonella from cats are cases where cats have eaten these birds lying dead or diseased on the ground (Söderlund et al. 2019). Such isolates are often S. Typhimurium and susceptible to all tested antibiotics. Therefore, only a selection of these isolates is tested. For details on methodology, see Chapter 6 - Materials and methods, Resistance in bacteria from animals.
A total of 108 Salmonella enterica ssp. enterica isolates were tested in 2025. Of all tested isolates, 75 were from domestic animals (Table 4.6). Salmonella Typhimurium was the dominant serovar with 42 isolates. Of these, 34 were from domestic animals (Table 4.7). The highest number of isolates was from pigs (n=18) belonging to eight different serovars dominated by S. Typhimurium (n=9). Also in cattle (n=17), S. Typhimurium was the most common serovar (n=5).
The majority of all isolates (92 of 108; 85%) were susceptible to all antibiotics tested and all isolates from wildlife were fully susceptible. Distributions of MICs and resistance for all isolates from domestic animals are presented in Table 4.6 and for the subset S. Typhimurium in Table 4.7. Sixteen isolates were resistant to one or more antibiotics (a table with resistance phenotypes is available as Supplementary material on the SVA web page. No interpretation was done for colistin due to uncertainties in ECOFFs caused by differences in MIC distributions between serovars. EUCAST no longer suggests a colistin ECOFF for Salmonella. Three isolates had an MIC of >2 mg/L for colistin (Table 4.6). Two of these three isolates belonged to serovar Dublin that often display a higher MIC to colistin than most other serovars. EUCAST has recently published a tentative ECOFF, (T)ECOFF, of 16 mg/L for colistin and S. Dublin. One isolate with an MIC of >2 mg/L for colistin was serovar Enteritidis and this isolate was tested with PCR for the presence of mcr-1 – mcr-9 genes, which may confer resistance to colistin.
| Antibiotic | Resistance (%) | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.016 | 0.03 | 0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | 64 | 128 | 256 | 512 | >512 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Amikacin | 1 | 4-128 | 4 | — | — | — | — | — | — | — | — | 98.7 | 1.3 | — | — | — | — | — | — | — |
| Ampicillin | 13 | 1-32 | 4 | — | — | — | — | — | — | 66.7 | 2.0 | — | — | — | — | 13.3 | — | — | — | — |
| Azithromycin | 0 | 2-64 | 16 | — | — | — | — | — | — | — | 32.0 | 52.0 | 14.7 | 1.3 | — | — | — | — | — | — |
| Cefotaxime | 0 | 0.25-4 | 0.5 | — | — | — | — | 100.0 | — | — | — | — | — | — | — | — | — | — | — | — |
| Ceftazidime | 0 | 0.25-8 | 2 | — | — | — | — | 77.3 | 22.7 | — | — | — | — | — | — | — | — | — | — | — |
| Chloramphenicol | 7 | 8-64 | 16 | — | — | — | — | — | — | — | — | — | 93.3 | — | — | — | 6.7 | — | — | — |
| Ciprofloxacin | 3 | 0.016-8 | 0.06 | 73.3 | 24.0 | — | — | 1.3 | 1.3 | — | — | — | — | — | — | — | — | — | — | — |
| Colistina | NA | 1-16 | NA | — | — | — | — | — | — | 90.7 | 5.3 | 4.0 | — | — | — | — | — | — | — | — |
| Gentamicin | 5 | 0.5-16 | 2 | — | — | — | — | — | 80.0 | 14.7 | — | — | — | — | 5.3 | — | — | — | — | — |
| Meropenem | 0 | 0.03-16 | 0.12 | — | 94.7 | 5.3 | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Nalidixic acid | 3 | 4-64 | 8 | — | — | — | — | — | — | — | — | 92.0 | 5.3 | 1.3 | — | — | 1.3 | — | — | — |
| Sulphamethoxazole | 19 | 8-512 | 256 | — | — | — | — | — | — | — | — | — | 17.3 | 33.3 | 12.0 | 17.3 | 1.3 | — | 1.3 | 17.3 |
| Tetracycline | 9 | 2-32 | 8 | — | — | — | — | — | — | — | 90.7 | — | — | — | 5.3 | 4.0 | — | — | — | — |
| Tigecycline | 0 | 0.25-8 | 0.5 | — | — | — | — | 97.3 | 2.7 | — | — | — | — | — | — | — | — | — | — | — |
| Trimethoprim | 9 | 0.25-16 | 2 | — | — | — | — | 77.3 | 12.0 | 1.3 | — | — | — | — | 9.3 | — | — | — | — | — |
| a One S. Enteritidis isolate with colistin MIC >2 was tested with PCR for the mcr-1 to mcr-9 genes and found negative. | ||||||||||||||||||||
| Antibiotic | Resistance (%) | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.016 | 0.03 | 0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | 64 | 128 | 256 | 512 | >512 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Amikacin | 3 | 4-128 | 4 | — | — | — | — | — | — | — | — | 97.1 | 2.9 | — | — | — | — | — | — | — |
| Ampicillin | 15 | 1-32 | 4 | — | — | — | — | — | — | 58.8 | 26.5 | — | — | — | — | 14.7 | — | — | — | — |
| Azithromycin | 0 | 2-64 | 16 | — | — | — | — | — | — | — | 41.2 | 47.1 | 11.8 | — | — | — | — | — | — | — |
| Cefotaxime | 0 | 0.25-4 | 0.5 | — | — | — | — | 100.0 | — | — | — | — | — | — | — | — | — | — | — | — |
| Ceftazidime | 0 | 0.25-8 | 2 | — | — | — | — | 88.2 | 11.8 | — | — | — | — | — | — | — | — | — | — | — |
| Chloramphenicol | 15 | 8-64 | 16 | — | — | — | — | — | — | — | — | — | 85.3 | — | — | — | 14.7 | — | — | — |
| Ciprofloxacin | 0 | 0.016-8 | 0.06 | 88.2 | 11.8 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Colistin | NA | 1-16 | NA | — | — | — | — | — | — | 91.2 | 8.8 | — | — | — | — | — | — | — | — | — |
| Gentamicin | 0 | 0.5-16 | 2 | — | — | — | — | — | 79.4 | 20.6 | — | — | — | — | — | — | — | — | — | — |
| Meropenem | 0 | 0.03-16 | 0.12 | — | 100.0 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Nalidixic acid | 0 | 4-64 | 8 | — | — | — | — | — | — | — | — | 97.1 | 2.9 | — | — | — | — | — | — | — |
| Sulphamethoxazole | 24 | 8-512 | 256 | — | — | — | — | — | — | — | — | — | 11.8 | 29.4 | 8.8 | 23.5 | 2.9 | — | — | 23.5 |
| Tetracycline | 18 | 2-32 | 8 | — | — | — | — | — | — | — | 82.4 | — | — | — | 11.8 | 5.9 | — | — | — | — |
| Tigecycline | 0 | 0.25-8 | 0.5 | — | — | — | — | 97.1 | 2.9 | — | — | — | — | — | — | — | — | — | — | — |
| Trimethoprim | 6 | 0.25-16 | 2 | — | — | — | — | 82.4 | 11.8 | — | — | — | — | — | 5.9 | — | — | — | — | — |
4.2.2 Campylobacter
Campylobacter coli was isolated from colon content samples collected from slaughter pigs at abattoirs as part of the monitoring of Escherichia coli resistant to ESCs. Isolates were identified to species level by MALDI-TOF MS. Samples from 190 pigs were cultured, yielding 176 C. coli isolates, and these samples were evenly distributed over the year. For details on methodology, see Chapter 6 - Materials and methods, Resistance in bacteria from animals.
Of the 176 isolates, 112 (64%) were susceptible to the six tested antibiotics. No resistance was recorded against chloramphenicol, ertapenem, gentamicin or tetracycline (Table 4.8). One isolate was resistant to erythromycin. In Campylobacter spp. isolated directly from animals, erythromycin resistance has only been found in two cases before (2017 and 2023). As in those two cases, whole-genome sequencing of the macrolide-resistant isolate revealed previously described target-altering mutations in the 23S rRNA genes (A2059G, E. coli numbering) (Bolinger and Kathariou 2017). No transferable macrolide resistance genes were found.
The level of quinolone resistance was comparable to previous years (Figure 4.3). Neither quinolones nor fluoroquinolones are authorised or used for treatment of groups of pigs via feed or water in Sweden. Additionally, a regulation (SJVFS 2023:21) has restricted the prescription of fluoroquinolones to animals in Sweden since 2013. Most of the consumption occurs in piglets treated individually with fluoroquinolones and, to a lesser extent, in other age categories (Sjölund et al. 2015). Any selection for quinolone resistance in Campylobacter therefore probably mainly occurs in sows and suckling piglets.
| Antibiotic | Resistance (%) | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | 64 | 128 | 256 | 512 | >512 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chloramphenicol | 0 | 2-64 | 16 | — | — | — | — | 79.0 | 18.8 | 2.3 | — | — | — | — | — | — | — |
| Ciprofloxacin | 36 | 0.12-32 | 0.5 | 59.7 | 4.0 | — | — | — | 4.0 | 18.8 | 13.1 | 0.6 | — | — | — | — | — |
| Ertapenem | 0 | 0.12-4 | 0.5 | 98.3 | 1.7 | — | — | — | — | — | — | — | — | — | — | — | — |
| Erythromycin | <1 | 1-512 | 8 | — | — | — | 82.4 | 13.6 | 2.8 | 0.6 | — | — | — | — | — | 0.6 | — |
| Gentamicin | 0 | 0.25-16 | 2 | — | 4.0 | 42.6 | 53.4 | — | — | — | — | — | — | — | — | — | — |
| Tetracycline | 0 | 0.5-64 | 2 | — | — | 100.0 | — | — | — | — | — | — | — | — | — | — | — |
4.3 Clinical isolates from animals
Isolates tested are from clinical submissions of samples to SVA, if not otherwise stated. For many samples, information on the indication for sampling was not available but the vast majority of submissions were likely from animals with infections. Therefore, data may be biased towards samples from treated animals or from herds where antibiotic treatment is common. Any assessments of trends are based on the assumption that this bias is inherent throughout the observation period. Furthermore, in some cases there was more than one animal sampled from the same herd. Likewise, regarding horses, dogs and cats, duplicates based on animal identity have not been excluded.
In Svarm, isolates are, when possible, classified as susceptible or resistant by ECOFFs issued by EUCAST (see Guidance for readers for details). This classifies isolates with acquired reduced susceptibility as resistant, which is relevant for monitoring purposes, but it should be understood that this does not always imply clinical resistance.
4.3.1 Pigs
Escherichia coli
Isolates of E. coli are from clinical submissions of faecal samples or samples taken post-mortem from the gastro-intestinal tract. The isolates are tested by PCR for genes coding for the virulence factors heat-labile enterotoxin (LT), heat-stable enterotoxin a and b (STa and STb), verocytotoxin (VT2e) and adhesion factors F4, F5, F6, F18 and F41. Only isolates with any of the mentioned virulence factors are included in Table 4.9.
| Antibiotic | Resistance % | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.03 | 0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | >32 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Ampicillin | 36 | 2–16 | 8 | — | — | — | — | — | — | 40.0 | 23.6 | — | — | 36.4 | — |
| Cefalexin | 2 | 4–32 | 32 | — | — | — | — | — | — | — | 54.5 | 40.0 | 3.6 | — | 1.8 |
| Cefotaxim | 0 | 0.25–2 | 0.25 | — | — | — | 100.0 | — | — | — | — | — | — | — | — |
| Colistin | 0 | 1–8 | 2 | — | — | — | — | — | 100.0 | — | — | — | — | — | — |
| Enrofloxacin | 13 | 0.12–4 | 0.12 | — | — | 87.3 | 9.1 | — | 3.6 | — | — | — | — | — | — |
| Gentamicin | 2 | 2–16 | 2 | — | — | — | — | — | — | 98.2 | — | 1.8 | — | — | — |
| Meropenem | 0 | 0.06–0.25 | 0.12 | — | 98.2 | 1.8 | — | — | — | — | — | — | — | — | — |
| Neomycin | 11 | 4–32 | 8 | — | — | — | — | — | — | — | 87.3 | 1.8 | — | 1.8 | 9.1 |
| Tetracycline | 29 | 2–16 | 8 | — | — | — | — | — | — | 70.9 | — | — | — | 29.1 | — |
| Trim-sulph.a | 27 | 0.5–4 | 0.5 | — | — | — | — | 72.7 | — | — | — | 27.3 | — | — | — |
| a Concentration of trimethoprim given, tested in concentration ratio 1/20 (trimethoprim-sulphamethoxazole). | |||||||||||||||
As in previous years, resistance to ampicillin, tetracycline and trimethoprim-sulphamethoxazole were the most common resistance traits. Resistance to ampicillin and to trimethoprim-sulphamethoxazole has increased considerably from 1995 with a peak in 2015-2016 but from 2019 there is a downward trend for trimethoprim-sulphamethoxazole (Figure 4.4). Resistance to neomycin was comparatively low throughout this period (1995-2025) despite increased sales of veterinary medicinal products aimed at treating post-weaning diarrhoea in later years (see Sales of antibiotics for animals, Comments on data by animal species). This differs from data displayed in Figure 4.5, taken from SVA’s interactive resistance monitoring tool SvarmIT, which includes all susceptibility-tested E. coli from pigs (i.e. not limited to ETEC). The occurrence of resistance to trimethoprim-sulphamethoxazole is also higher in the material in SvarmIT. The reason for the observed differences is unclear; however, it should be noted that the number of isolates is relatively small for both materials.
Brachyspira hyodysenteriae
Isolates of Brachyspira hyodysenteriae are from clinical submissions of faecal samples. The number of isolates each year varies (n=4-29, 2025 n=9). In routine diagnostics at SVA, clinical breakpoints at >2 mg/L for tiamulin and >16 mg/L for tylosin are used. Analysis of antibiotic susceptibility data from isolates of B. hyodysenteriae from Sweden 1990-2010 resulted in a proposal for wild type cut-off values (Pringle et al. 2012). In Table 4.10, these cut-off values are used on all data. With the suggested wild type cut-off value >0.25 mg/L for tiamulin, resistance is detected throughout the period. During 2016 and 2017, therapeutic failure of tiamulin was observed in an outbreak of swine dysentery that involved several herds. The outbreak was shown to be caused by a B. hyodysenteriae clone with MIC of tiamulin above the clinical breakpoint. Fortunately, the clone was susceptible to macrolides and could be eradicated. Tylosin resistance has decreased over the years but increased slightly in 2018-2025.
| Antibiotic | 2009-2011 Resistance % | 2012-2017 Resistance % | 2018-2025 Resistance % | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.03 | 0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | 64 | 128 | >128 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doxycycline | 5 | 0 | 0 | 0.12–16 | 0.5 | — | — | 31.1 | 57.4 | 11.5 | — | — | — | — | — | — | — | — | — |
| Tiamulin | 8 | 16a | 8 | 0.06–16 | 0.25 | — | 42.6 | 18.0 | 31.1 | 4.9 | 3.3 | — | — | — | — | — | — | — | — |
| Tylosin | 60 | 42 | 66 | 2–128 | 16 | — | — | — | — | — | — | 13.1 | 11.5 | 9.8 | — | 1.6 | 1.6 | — | 62.3 |
| Tylvalosin | 55 | 51 | 66 | 0.25–32 | 1 | — | — | — | 3.3 | 16.4 | 14.8 | 3.3 | 9.8 | 31.1 | 16.4 | — | 4.9 | — | — |
| Valnemulin | 3 | 24 | 7 | 0.03–4 | 0.12 | 52.5 | 34.4 | 6.6 | — | 4.9 | — | 1.6 | — | — | — | — | — | — | — |
| a Five isolates with MICs above 2 mg/L from a defined outbreak in 2016-2017. | |||||||||||||||||||
Brachyspira pilosicoli
Isolates of Brachyspira pilosicoli are from clinical submissions of faecal samples. ECOFFs for B. pilosicoli are not defined for the antibiotics tested. The assessed percentage of resistance using the same wild type cut-off value as for B. hyodysenteriae is shown in Table 4.11.
If clinical breakpoints for Brachyspira hyodysenteriae are used as guide for the choice of antibiotic for treatment of spirochaetal diarrhoea, 9% are resistant to tiamulin (>2 mg/L).
| Antibiotic | Resistance %a | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.03 | 0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | 64 | 128 | >128 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doxycycline | 5 | 0.12–16 | 0.5 | — | — | 78.6 | 12.8 | 3.4 | 4.3 | 0.9 | — | — | — | — | — | — | — |
| Tiamulin | 18 | 0.06–16 | 0.25 | — | 63.2 | 13.7 | 5.1 | 1.7 | 3.4 | 4.3 | 1.7 | 2.6 | 4.3 | — | — | — | — |
| Tylosin | 28 | 2–128 | 16 | — | — | — | — | — | — | 42.7 | 17.1 | 10.3 | 1.7 | 2.6 | 6.0 | 4.3 | 15.4 |
| Tylvalosin | 39 | 0.25–32 | 1 | — | — | — | 4.3 | 35.0 | 21.4 | 19.7 | 8.5 | 0.9 | 1.7 | 1.7 | 6.8 | — | — |
| Valnemulin | 14 | 0.03–4 | 0.12 | 60.7 | 13.7 | 12.0 | 5.1 | 4.3 | 1.7 | 0.9 | — | 1.7 | — | — | — | — | — |
| a Assessed percentage of resistance using wild type cut-off values for B. hyodysenteriae. | |||||||||||||||||
Resistance to tylosin has decreased from a high level (60-70%) around 2010 to 2015, then there was an increase from 2016 that now seems to have stopped. Resistance to tiamulin has remained at a steady level during the same time period (Figure 4.6). However, the number of isolates analysed per year is low. In 2025, two isolates were resistant to tiamulin and valnemulin as well as tylosin and tylvalosin.
Actinobacillus pleuropneumoniae
Isolates of Actinobacillus pleuropneumoniae are mostly from post-mortem investigations of lungs. Isolates from 2024 and 2025 were included in the MIC distribution. From 2024, 17 isolates were collected in a SvarmPat project (see In-focus - SvarmPat) where acute lesions in lungs and pericardium were sampled at slaughter. Data from 2025 and back to 2005 show that the resistance situation is favourable and almost no resistance has been detected to tested antibiotics during this period, including penicillin (Table 4.12). Since pneumonia caused by A. pleuropneumoniae is an important disease in pigs, sampling and susceptibility testing is desirable if emerging resistance is to be detected early. For treatment of Actinobacillus pleuropneumoniae with MICs within the wild type distribution of penicillin (MIC 0.12 – 0.5 mg/L), increased exposure to penicillin is required (Swedish Medical Products Agency 2022). Exposure includes e.g. administration route, dose and dosing interval.
| Antibiotic | Resistance % | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.016 | 0.03 | 0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | >32 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Ampicillin | 0 | 0.06–1 | 0.5 | — | — | — | 83.8 | 16.2 | — | — | — | — | — | — | — | — |
| Doxycycline | 0 | 0.06–2 | 2 | — | — | — | — | 16.2 | 83.8 | — | — | — | — | — | — | — |
| Enrofloxacin | 0 | 0.016–0.5 | 0.12 | — | 86.5 | 13.5 | — | — | — | — | — | — | — | — | — | — |
| Florfenicol | 0 | 1–32 | 1 | — | — | — | — | — | — | 100.0 | — | — | — | — | — | — |
| Gamithromycin | 1 | 0.5–16 | 4 | — | — | — | — | — | — | 2.7 | 43.2 | 52.7 | 1.4 | — | — | — |
| Penicillin | 0 | 0.03–1 | 1 | — | — | — | 1.4 | 86.5 | 12.2 | — | — | — | — | — | — | — |
| Tetracycline | 0 | 0.12–4 | 2 | — | — | — | 1.4 | 62.2 | 36.5 | — | — | — | — | — | — | — |
| Trim-Sulph.a | 1 | 0.03–1 | 0.25 | — | 1.4 | 37.8 | 59.5 | — | — | — | 1.4 | — | — | — | — | — |
| a Concentration of trimethoprim given, tested in concentration ratio 1/20 (trimethoprim/sulphamethoxazole). | ||||||||||||||||
Pasteurella multocida
Clinical isolates of Pasteurella multocida are mostly from the respiratory tract. Eight of the isolates from 2024 were collected in a SvarmPat project (see In-focus - SvarmPat) where acute lesions in lungs and pericardium were sampled at slaughter. All tested isolates were susceptible to relevant antibiotics including penicillin, however three isolates were resistant to trimetoprim-sulphamethoxazole (Table 4.13).
| Antibiotic | Resistance % | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.016 | 0.03 | 0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | >32 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Ampicillin | 0 | 0.06–1 | 0.5 | — | — | 4.8 | 50.0 | 45.2 | — | — | — | — | — | — | — | — |
| Doxycycline | 0 | 0.06–2 | 1 | — | — | — | 11.9 | 71.4 | 16.7 | — | — | — | — | — | — | — |
| Enrofloxacin | 0 | 0.016–0.5 | 0.06 | 100.0 | — | — | — | — | — | — | — | — | — | — | — | — |
| Florfenicol | 0 | 1–32 | 1 | — | — | — | — | — | — | 100.0 | — | — | — | — | — | — |
| Gamithromycin | 0 | 0.5–16 | 4 | — | — | — | — | — | — | 16.7 | 57.1 | 26.2 | — | — | — | — |
| Penicillin | 0 | 0.03–1 | 0.5 | — | — | 42.9 | 57.1 | — | — | — | — | — | — | — | — | — |
| Tetracycline | 0 | 0.12–4 | 2 | — | — | — | 4.8 | 64.3 | 31.0 | — | — | — | — | — | — | — |
| Trim-Sulph.a | 7 | 0.03–1 | 0.25 | — | 26.2 | 47.6 | 14.3 | 4.8 | 2.4 | — | 4.8 | — | — | — | — | — |
| a Concentration of trimethoprim given, tested in concentration ratio 1/20 (trimethoprim/sulphamethoxazole). | ||||||||||||||||
Streptococcus suis
Isolates of Streptococcus suis are from post-mortem examination of different organs in diseased pigs from 2022-2025 (n=47) (Table 4.14). Resistance to penicillin has become a more common trait in recent years.
| Antibiotic | Resistance % | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.03 | 0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | >4 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clindamycin | 32 | 0.5–2 | 0.5 | — | — | — | — | 68.1 | 4.3 | 4.3 | 23.4 | — |
| Enrofloxacin | NA | 0.25–1 | NA | — | — | — | 27.7 | 66.0 | 6.4 | — | — | — |
| Erytromycin | 9 | 0.5–2 | 0.5 | — | — | — | — | 91.5 | 4.3 | — | 4.3 | — |
| Fusidic acid | NA | 0.5–2 | NA | — | — | — | — | — | 100.0 | — | — | — |
| Gentamicin | NA | 1–4 | NA | — | — | — | — | — | 8.5 | 31.9 | 51.1 | 8.5 |
| Oxacillin | NA | 0.25–1 | NA | — | — | — | 93.6 | 4.3 | 2.1 | — | — | — |
| Penicillin | 13 | 0.03–1 | 0.12 | 80.4 | 4.3 | 2.2 | 4.3 | 4.3 | 4.3 | — | — | — |
| Tetracycline | 66 | 0.25–4 | 0.5 | — | — | — | 31.9 | 2.1 | 8.5 | 31.9 | 19.1 | 6.4 |
| Trim-Sulph.a | 13 | 0.25–4 | 0.25 | — | — | — | 87.2 | — | 2.1 | 8.5 | — | 2.1 |
| a Concentration of trimethoprim given, tested in concentration ratio 1/20 (trimethoprim/sulphamethoxazole). | ||||||||||||
4.3.2 Cattle
Escherichia coli from milk samples
Isolates of E. coli are from clinical submissions of milk samples from dairy cows. It is likely that most sampled cows had clinical mastitis.
Most of the isolates (70%, 34/49) were susceptible to all antibiotics tested, which is less than previous years (78% in 2024, 89% in 2023, 85% in 2022). Resistance to ampicillin and trimethoprim-sulphamethoxazole was the most common profile, followed by ampicillin and tetracycline and a combination of all three. (Table 4.15). Four isolates (8%) were multiresistant, i.e. resistant to three or more antibiotics: two isolates resistant to ampicillin, tetracycline and trimethoprim-sulphamethoxazole; one isolate resistant to ampicillin, neomycin and trimethoprim-sulphamethoxazole and one isolate resistant to ampicillin, cefalexin, cefotaxime and enrofloxacin. The isolate resistant to cefotaxime was found to carry the blaCTX-M-15 gene. To our knowledge, it is the first ESBL producing E. coli isolate from mastitis in Sweden.
| Antibiotic | Resistance % | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | >32 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Ampicillin | 20 | 2–16 | 8 | — | — | — | — | — | 38.8 | 38.8 | 2.0 | — | 20.4 | — |
| Cefalexin | 2 | 4–32 | 32 | — | — | — | — | — | — | 30.6 | 63.3 | 4.1 | — | 2.0 |
| Cefotaxim | 2 | 0.25–2 | 0.25 | — | — | 98.0 | — | — | — | 2.0 | — | — | — | — |
| Colistin | 0 | 1–8 | 2 | — | — | — | — | 100.0 | — | — | — | — | — | — |
| Enrofloxacin | 4 | 0.12–4 | 0.12 | — | 95.9 | — | 4.1 | — | — | — | — | — | — | — |
| Gentamicin | 0 | 2–16 | 2 | — | — | — | — | — | 100.0 | — | — | — | — | — |
| Meropenem | 0 | 0.06–0.25 | 0.12 | 100.0 | — | — | — | — | — | — | — | — | — | — |
| Neomycin | 2 | 4–32 | 8 | — | — | — | — | — | — | 98.0 | — | — | 2.0 | — |
| Tetracycline | 12 | 2–16 | 8 | — | — | — | — | — | 83.7 | 4.1 | — | — | 12.2 | — |
| Trim-sulph. | 14 | 0.5–4 | 0.5 | — | — | — | 85.7 | 2.0 | — | — | 12.2 | — | — | — |
Klebsiella pneumoniae from milk samples
Isolates of Klebsiella pneumoniae are from clinical submissions of milk samples from dairy cows (Table 4.16). It is likely that most sampled cows had clinical mastitis. Klebsiella pneumoniae has an inherent low susceptibility to ampicillin but there is no available ECOFF. Excluding ampicillin, 37 of 38 isolates were susceptible to all tested antibiotics. One isolate was resistant to gentamicin.
| Antibiotic | Resistance % | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | >32 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Ampicillin | NR | 2–16 | NR | — | — | — | — | — | — | 5.3 | 10.5 | 60.5 | 23.7 | — |
| Cefotaxim | 0 | 0.25–2 | 0.25 | — | — | 100.0 | — | — | — | — | — | — | — | — |
| Colistin | 0 | 1–8 | 2 | — | — | — | — | 100.0 | — | — | — | — | — | — |
| Enrofloxacin | 0 | 0.12–4 | 0.12 | — | 100.0 | — | — | — | — | — | — | — | — | — |
| Gentamicin | 3 | 2–16 | 2 | — | — | — | — | — | 97.4 | 2.6 | — | — | — | — |
| Meropenem | 0 | 0.06–0.25 | 0.12 | 100.0 | — | — | — | — | — | — | — | — | — | — |
| Neomycin | 0 | 4–32 | 4 | — | — | — | — | — | — | 100.0 | — | — | — | — |
| Tetracycline | 0 | 2–16 | 8 | — | — | — | — | — | 100.0 | — | — | — | — | — |
| Trim-sulph.a | 0 | 0.5–4 | 0.5 | — | — | — | 100.0 | — | — | — | — | — | — | — |
| a Concentration of trimethoprim given, tested in concentration ratio 1/20 (trimethoprim/sulphamethoxazole). | ||||||||||||||
Staphylococcus aureus from milk samples
Isolates of Staphylococcus aureus are from clinical submissions of milk samples from dairy cows with clinical mastitis. In 2025, 629 isolates of S. aureus were analysed for penicillinase production, and 1.7% (n=11) were positive. Between 2019 and 2025, the numbers have varied between 1.2% and 3.1%.
Pasteurella multocida
Most isolates of Pasteurella multocida are from nasal swabs from calves with respiratory disease or from post-mortem investigations of lungs. Because of a change of panel design, direct comparison with data from earlier years is not possible. For older data see earlier Swedres-Svarm reports.
Antibiotic resistance was generally rare among isolates of P. multocida (Table 4.17), but beta-lactamase producing P. multocida have been isolated every year since 2016 (Figure 4.7). In 2025, one isolate was resistant to penicillin and ampicillin and was positive in the beta-lactamase test. Further, five other isolates from different farms were trimethoprim-sulphamethoxazole resistant. Penicillin is considered the first-choice antibiotic for treating pneumonia in cattle in Sweden. Sampling and susceptibility testing is important for early detection of resistance, especially in cases of therapeutic failure.
| Antibiotic | Resistance (%) | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.016 | 0.03 | 0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | >32 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Ampicillin | 3 | 0.06-1 | 0.5 | — | — | — | 48.5 | 45.5 | 3.0 | 3.0 | — | — | — | — | — | — |
| Ceftiofur | 0 | 0.12-4 | 0.12 | — | — | — | 100.0 | — | — | — | — | — | — | — | — | — |
| Enrofloxacin | 0 | 0.016-0.5 | 0.06 | 87.9 | 12.1 | — | — | — | — | — | — | — | — | — | — | — |
| Florfenicol | 0 | 1-32 | 1 | — | — | — | — | — | — | 100.0 | — | — | — | — | — | — |
| Gamithromycin | 0 | 0.5-16 | 4 | — | — | — | — | — | 3.0 | 21.2 | 66.7 | 9.1 | — | — | — | — |
| Gentamicin | NR | 1-4 | NR | — | — | — | — | — | — | — | 6.1 | 39.4 | 51.5 | — | — | — |
| Penicillin | 3 | 0.03-1 | 0.5 | — | 3.0 | 36.4 | 54.5 | 3.0 | — | — | 3.1 | — | — | — | — | — |
| Tetracycline | 0 | 0.12-4 | 2 | — | — | — | 9.1 | 69.7 | 12.1 | 9.1 | — | — | — | — | — | — |
| Trim-sulph.a | 15 | 0.03-1 | 0.12 | — | 12.1 | 45.5 | 27.3 | 9.1 | 3.0 | — | 3.1 | — | — | — | — | — |
| a Concentration of trimethoprim given, tested in concentration ratio 1/20 (trimethoprim/sulphamethoxazole). | ||||||||||||||||
Mycoplasma bovis
Isolates of Mycoplasma bovis are from clinical submissions of nasal swabs or post-mortem investigations of lungs from calves with respiratory disease from 2024-2025. Recently published ECOFFs for enrofloxacin and florfenicol are used in Table 4.18. All isolates were susceptible to enrofloxacin, and one isolate (2%) was resistant to florfenicol. In the isolates from 2020-2023 no florfenicol resistance was detected (see Swedres-Svarm 2023). For tetracycline and gamithromycin, the MICs were higher than the tested range in 81% and 92% of the isolates, respectively. Mycoplasmas are intrinsically resistant to beta-lactams due to their lack of cell wall.
| Antibiotic | Resistance (%) 2025 | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.016 | 0.03 | 0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | >32 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Enrofloxacin | 0 | 0.016-0.5 | 1 | — | — | — | 6.4 | 93.6 | — | — | — | — | — | — | — | — |
| Florfenicol | 2 | 1-32 | 16 | — | — | — | — | — | — | — | — | 2.1 | 63.8 | 31.9 | — | 2.1 |
| Gamithromycin | NA | 0.5-16 | NA | — | — | — | — | — | — | — | — | 2.1 | 2.1 | 14.9 | 80.9 | — |
| Penicillin | NA | 0.03-1 | NA | — | — | — | — | — | — | — | 100.0 | — | — | — | — | — |
| Tetracycline | NA | 0.12-4 | NA | — | — | — | — | — | — | — | 2.1 | 6.4 | 91.5 | — | — | — |
4.3.3 Farmed fish
Flavobacterium psychrophilum
Isolates of Flavobacterium psychrophilum are from clinical submissions of farmed fish, most of them from outbreaks of disease. More than one isolate can be analysed from the same outbreak. More than one phenotype is detected in more than half of such cases (data not shown). Data from 2021-2025 are compiled and presented as distributions of MICs in Table 4.19. Most isolates are from rainbow trout. Epidemiological cut-offs issued by CLSI are used (Clinical and Laboratory Standards Institute (CLSI) 2020) when available. Resistance to oxolinic acid and oxytetracycline was high in this material whereas no resistance to florfenicol was detected.
In Figure 4.8 resistance to tetracycline and quinolones (nalidixic acid or oxolinic acid) in F. psychrophilum 2005-2025 is shown. A three-year moving average is used. There is a marked increase in resistance to these antibiotics over the years despite a limited use up until recently (see Sales of antibiotics for animals, Comments on data by animal species). For nalidixic acid/oxolinic acid a downward trend was seen after a peak in 2012, however this downward trend has turned in the latest years. Genome sequencing was used for analysis of a temporally and geographically representative set of F. psychrophilum isolates from outbreaks among Swedish farmed salmonid fish. The results indicate repeated nationwide introductions of new clones, presumably by trade of fish and eggs. It is probable that such introductions have contributed to the observed increase in resistance (Söderlund et al. 2018).
| Antibiotic | Resistance (%) | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.008 | 0.016 | 0.03 | 0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | >8 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Florfenicol | 0 | 0.12-8 | 2 | — | — | — | — | 3.9 | 34.2 | 44.7 | 15.8 | 1.3 | — | — | — |
| Oxolinic acid | 63 | 0.008-1 | 0.25 | — | — | — | 1.3 | 7.9 | 27.6 | 15.8 | 11.8 | 35.5 | — | — | — |
| Oxytetracycline | 85 | 0.03-4 | 0.12 | — | — | — | 13.3 | 1.3 | 1.3 | 4.0 | 2.7 | 29.3 | 30.7 | 17.3 | — |
| Trim-sulph.a | NA | 0.03-2 | NA | — | — | — | — | — | — | 18.5 | 44.4 | 14.8 | 22.2 | — | — |
| a Concentration of trimethoprim given, tested in concentration ratio 1/20 (trimethoprim/sulphamethoxazole). | |||||||||||||||
Flavobacterium columnare
Isolates of Flavobacterium columnare are from clinical submissions of farmed fish. Data from 2020-2025 are compiled and presented as distributions of MICs in Table 4.20. Most isolates of F. columnare are from rainbow trout and brown trout. Epidemiological cut-offs issued by CLSI are used (Clinical and Laboratory Standards Institute (CLSI) 2020) except for trimethoprim-sulphamethoxazole.
| Antibiotic | Resistance (%) | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.008 | 0.016 | 0.03 | 0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | >8 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Florfenicol | 2 | 0.12-8 | 4 | — | — | — | — | 7.3 | 14.6 | 34.1 | 34.1 | 2.4 | 4.9 | — | 2.4 |
| Oxolinic acid | 2 | 0.008-1 | 0.25 | 2.4 | 7.3 | 4.9 | 31.7 | 46.3 | 4.9 | — | — | 2.4 | — | — | — |
| Oxytetracycline | 5 | 0.03-4 | 0.25 | — | — | 43.9 | 41.5 | 2.4 | 2.4 | 4.9 | — | — | — | — | — |
| Trim-sulph.a | 0 | 0.03-4 | 0.5 | — | — | 50.0 | 8.3 | 16.7 | 16.7 | 8.3 | — | — | — | — | — |
| a Concentration of trimethoprim given, tested in concentration ratio 1/20 (trimethoprim/sulphamethoxazole). | |||||||||||||||
Aeromonas salmonicida var. salmonicida
Isolates of Aeromonas salmonicida var. salmonicida are from clinical submissions of farmed fish. Data from 2021-2025 are compiled and presented as distributions of MICs in Table 4.21. Most isolates are from trout. Epidemiological cut-offs issued by CLSI are used (Clinical and Laboratory Standards Institute (CLSI) 2020) except for trimethoprim-sulphamethoxazole.
| Antibiotic | Resistance (%) | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.008 | 0.016 | 0.03 | 0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | >8 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Florfenicol | 0 | 0.12-8 | 4 | — | — | — | — | 2.6 | 43.6 | 53.8 | — | — | — | — | — |
| Oxolinic acid | 3 | 0.008-1 | 0.12 | 15.4 | 71.8 | 7.7 | — | 2.6 | — | 2.6 | — | — | — | — | — |
| Oxytetracycline | 0 | 0.03-4 | 1 | — | — | 2.6 | 2.6 | 28.2 | 66.7 | — | — | — | — | — | — |
| Trim-sulph.a | 0 | 0.03-2 | 0.5 | — | — | 46.7 | 20.0 | 33.3 | — | — | — | — | — | — | — |
| a Concentration of trimethoprim given, tested in concentration ratio 1/20 (trimethoprim/sulphamethoxazole). | |||||||||||||||
4.3.4 Laying hens
Escherichia coli
Isolates of Escherichia coli are from samples taken at post-mortem examination of laying hens from commercial farms.
Usually more than one hen from the same farm is submitted for examination in disease outbreaks. Resistance to enrofloxacin has decreased in recent years, from 39% in 2017–2018 Swedres-Svarm 2018 to 12% in 2024–2025. (Table 4.22).
| Antibiotic | Resistance % | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | >32 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Ampicillin | 13 | 2–16 | 8 | — | — | — | — | — | 38.0 | 49.4 | — | — | 12.7 | — |
| Cefotaxime | 0 | 0.25–2 | 0.25 | — | — | 100.0 | — | — | — | — | — | — | — | — |
| Colistin | 0 | 1–8 | 2 | — | — | — | — | 98.7 | 1.3 | — | — | — | — | — |
| Enrofloxacin | 8 | 0.12–4 | 0.12 | — | 92.4 | 3.8 | 1.3 | 1.3 | 1.3 | — | — | — | — | — |
| Gentamicin | 1 | 2–16 | 2 | — | — | — | — | — | 98.7 | — | — | — | 1.3 | — |
| Meropenem | 0 | 0.06–0.25 | 0.12 | 100.0 | — | — | — | — | — | — | — | — | — | — |
| Neomycin | 0 | 4–32 | 8 | — | — | — | — | — | — | 97.5 | 2.5 | — | — | — |
| Tetracycline | 5 | 2–16 | 8 | — | — | — | — | — | 89.9 | 5.1 | — | — | 5.1 | — |
| Trim-sulph.a | 0 | 0.5–4 | 0.5 | — | — | — | 100.0 | — | — | — | — | — | — | — |
| a Concentration of trimethoprim given, tested in concentration ratio 1/20 (trimethoprim/sulphamethoxazole). | ||||||||||||||
4.3.5 Horses
Escherichia coli
Isolates of Escherichia coli are from clinical submissions of samples from the genital tract of mares. As in previous years, resistance to trimethoprim-sulphamethoxazole was the most common trait in 2025 (Figure 4.9 and Table 4.23). Occurrence of resistance to gentamicin has been continuously low from 2013 and onwards, ≤5% (Figure 4.9). However, this resistance has varied somewhat over the years and trends are difficult to estimate.
Eighty five percent (178/210) of the isolates were susceptible to all the tested antibiotics. The proportion of multiresistance was 2% (4/210). Two of the four multiresistant isolates were resistant to three antibiotics, one isolate to four antibiotics and one isolate to five antibiotics. The most common phenotype was resistance to ampicillin, gentamicin and trimethoprim-sulphamethoxazole. For comparison of resistance in E. coli of different origin see Chapter 5 - Comparative analysis.
One of the isolates was resistant to cefotaxime and one to colistin, both were available for further testing. Genes conferring transferable ESC resistance were not detected in the one isolate resistant to cefotaxime (MIC >0.25mg/L) and PCR analysis of the mcr-1 to mcr-9 genes in the isolate resistant to colistin was negative. No isolate was resistant to meropenem.
| Antibiotic | Resistance (%) | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | >32 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Ampicillin | 3 | 2-16 | 8 | — | — | — | — | — | 45.7 | 46.7 | 4.3 | 0.5 | 2.9 | — |
| Cefotaxime | <1 | 0.25-2 | 0.25 | — | — | 99.5 | — | — | — | 0.5 | — | — | — | — |
| Colistin | <1 | 1-8 | 2 | — | — | — | — | 99.5 | — | — | — | 0.5 | — | — |
| Enrofloxacin | 1 | 0.12-4 | 0.12 | — | 98.6 | — | 1.0 | 0.5 | — | — | — | — | — | — |
| Gentamicin | 2 | 2-16 | 2 | — | — | — | — | — | 98.1 | 0.5 | 0.5 | — | 1.0 | — |
| Meropenem | 0 | 0.06-0.25 | 0.12 | 100.0 | — | — | — | — | — | — | — | — | — | — |
| Neomycin | 0 | 4-32 | 8 | — | — | — | — | — | — | 99.0 | 1.0 | — | — | — |
| Tetracycline | 4 | 2-16 | 8 | — | — | — | — | — | 93.8 | 2.4 | — | — | 3.8 | — |
| Trim-sulph.a | 11 | 0.5-4 | 0.5 | — | — | — | 88.6 | 1.4 | — | — | 10.0 | — | — | — |
| a Concentration of trimethoprim given, tested in concentration ratio 1/20 (trimethoprim-sulphamethoxazole). | ||||||||||||||
Streptococcus equi ssp. zooepidemicus
Isolates of Streptococcus equi ssp. zooepidemicus are from clinical submissions, mainly from the respiratory tract (72%), of horses.
Over the years, most of the isolates (91% in 2025) have been susceptible to all relevant tested antibiotics, gentamicin and tetracycline not included. Streptococcus equi ssp. zooepidemicus has a low inherent susceptibility to aminoglycosides (e.g. gentamicin) and tetracyclines.
In 2025, resistance to clindamycin and trimethoprim-sulphamethoxazole was detected. None of the isolates were resistant to penicillin. Any reduced susceptibility to penicillin in beta-hemolytic streptococci should be controlled, i.e. if tested on pure culture and ensuring that organism identification and antimicrobial susceptibility test are accurate and reproducible. All isolates were screened for erythromycin-induced clindamycin resistance, and no isolates displayed such resistance (Table 4.24). The number of isolates is low and varies each year (n=43-102, 2025 n=74), which could cause minor variations between years.
| Antibiotic | Resistance (%) | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.03 | 0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | >4 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cefalexin | 0 | 1-4 | 2 | — | — | — | — | — | 97.3 | 2.7 | — | — |
| Clindamycin | 7a | 0.5-2 | 0.5 | — | — | — | 100.0 | — | — | — | — | — |
| Erythromycin | 0 | 0.5-2 | 0.25 | — | — | — | — | — | 2.7 | — | 6.8 | 90.5 |
| Gentamicin | NR | 1-4 | NR | — | — | — | 68.9 | 24.3 | 5.4 | 1.4 | — | — |
| Penicillin | 0 | 0.03-1 | 0.03 | 100.0 | — | — | — | — | — | — | — | — |
| Tetracycline | NR | 0.25-4 | NR | — | — | — | 2.7 | — | — | 37.8 | 43.2 | 16.2 |
| Trim-sulph.b | 3 | 0.25-4 | 0.5 | — | — | — | 95.9 | 1.4 | — | 1.4 | — | 1.4 |
| a Denotes resistance, including inducible resistance (0 isolates). | ||||||||||||
| b Concentration of trimethoprim given, tested in concentration ratio 1/20 (trimethoprim/sulphamethoxazole). | ||||||||||||
Staphylococcus aureus
Isolates of Staphylococcus aureus are from clinical submissions of samples from skin lesions, excluding wounds and abscesses, from horses. Due to the introduction of an AMR panel with substances and cut-off values for topical treatment, the number of isolates tested for systemic treatment has declined during the past years.
Resistance to penicillin due to penicillinase production is still the most common trait (25%). A new routine has been implemented in the diagnostic lab in 2024 – all Staphylococcus aureus isolates from horses are tested for penicillinase production as in previous years, but not all of the negative isolates are tested on the full AMR panel for staphylococci. Instead, they are followed by a comment to the clinician that the isolate does not produce beta-lactamase and can be treated with penicillin. Isolates tested on the full AMR panel are reported in Table 4.25.
The proportions of resistance to gentamicin, tetracycline and trimethoprim-sulphamethoxazole have differed slightly over the years and trends are difficult to estimate (Figure 4.10). Resistance to fusidic acid has varied and increased to 6% in 2025 (Table 4.25 and previous Swedres-Svarm reports).
| Antibiotic | Resistance (%) | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.03 | 0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | 64 | >64 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cefalexin | 0 | 1-4 | 4 | — | — | — | — | — | — | 64.2 | 35.8 | — | — | — | — | — |
| Cefoxitin | 0 | 2-8 | 4 | — | — | — | — | — | — | 11.3 | 88.7 | — | — | — | — | — |
| Clindamycin | 6a | 0.25-2 | 0.25 | — | — | — | 94.3 | 3.8 | — | — | 1.9 | — | — | — | — | — |
| Enrofloxacin | 0 | 0.25-1 | 0.5 | — | — | — | 96.2 | 3.8 | — | — | — | — | — | — | — | — |
| Erythromycin | 4 | 0.25-2 | 1 | — | — | — | 52.8 | 41.5 | 1.9 | — | 3.8 | — | — | — | — | — |
| Fusidic acid | 6 | 0.25-1 | 0.5 | — | — | — | 86.8 | 7.5 | — | 5.7 | — | — | — | — | — | — |
| Gentamicin | 6 | 1-4 | 2 | — | — | — | — | — | 92.5 | 1.9 | — | 5.7 | — | — | — | — |
| Nitrofurantoin | 0 | 16-64 | 32 | — | — | — | — | — | — | — | — | — | 86.8 | 13.2 | — | — |
| Penicillin | 25b | 0.03-1 | NA | 58.5 | 7.5 | 1.9 | 3.8 | 3.8 | 9.4 | 15.1 | — | — | — | — | — | — |
| Tetracycline | 8 | 0.25-4 | 1 | — | — | — | 54.7 | 30.2 | 7.5 | 1.9 | — | 5.7 | — | — | — | — |
| Trim-sulph.c | 19 | 0.25-4 | 0.25 | — | — | — | 81.1 | 15.1 | — | 3.8 | — | — | — | — | — | — |
| a Denotes resistance, including inducible resistance (1 isolate). | ||||||||||||||||
| b Denotes beta-lactamase production, all tested isolates included (n=85). | ||||||||||||||||
| c Concentration of trimethoprim given, tested in concentration ratio 1/20 (trimethoprim/sulphamethoxazole). | ||||||||||||||||
Forty-seven percent (25/53) were susceptible to all the tested antibiotics. Four isolates (8%) were resistant to three or more of the tested antibiotics (i.e. multiresistant), compared to the figures in 2015-2024 (0-5%) (see previous Swedres-Svarm reports). No isolate was resistant to cefoxitin (MIC >4 mg/L). For more information on MRSA isolated from horses in Sweden, see Notifiable diseases, Methicillin-resistant Staphylococcus aureus (MRSA).
The isolates were screened for erythromycin-induced clindamycin resistance; one isolate displayed such resistance.
Actinobacillus
Isolates of Actinobacillus spp. are from clinical submissions of samples from various anatomical sites, of which the most common are wounds (39%) and respiratory tract (16%). Nine percent of the samples are from abscesses. For Actinobacillus spp. isolated from horses, ECOFFs for A. pleuropneumoniae have been used regarding penicillin, tetracycline, enrofloxacin and trimethoprim-sulphamethoxazole. For other antibiotics, clinical breakpoints have been applied (Table 4.26).
| Antibiotic | Resistance (%) | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.016 | 0.03 | 0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | >4 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Enrofloxacin | 3 | 0.016-0.5 | 0.12 | 78.9 | 17.5 | 0.9 | — | 1.8 | 0.9 | — | — | — | — |
| Gentamicin | NR | 1-4 | NR | — | — | — | — | — | — | 7.9 | 32.5 | 50.0 | 9.6 |
| Penicillin | 7 | 0.03-1 | 1 | — | 2.6 | 5.3 | 13.2 | 46.5 | 22.8 | 2.6 | 7.0 | — | — |
| Tetracycline | 0 | 0.12-4 | 2 | — | — | — | 2.6 | 44.7 | 50.0 | 2.6 | — | — | — |
| Trim-sulph.a | 2 | 0.03-1 | 0.25 | — | 72.8 | 13.2 | 6.1 | 6.1 | 0.9 | — | 0.9 | — | — |
| a Concentration of trimethoprim given, tested in concentration ratio 1/20 (trimethoprim/sulphamethoxazole). | |||||||||||||
Eighty one percent (92/114) of the isolates were susceptible to all the tested antibiotics. Seven percent (8/114) were resistant to penicillin, MIC>1 and 2% to trimethoprim-sulphamethoxazole. All but one isolate with MIC >0.25 mg/L for penicillin (n=37), were tested for penicillinase production. Five were positive, one with MIC 0.5 mg/L and four with MIC >1 mg/L. The Actinobacillus spp. wild type distribution of penicillin (MIC 0.03 - 1 mg/L) requires increased exposure for successful treatment (Swedish Medical Products Agency 2015). Exposure includes e.g. administration route, dose and dose interval.
Rhodococcus equi
Isolates of Rhodococcus equi (n=11) are from various anatomical sites of which the most common was the respiratory tract of foals.
Rhodococcus equi has inherent low susceptibility to most antimicrobials. However, none of the isolates investigated in 2025 showed resistance to rifampicin, clarithromycin or erythromycin.
One isolate resistant to rifampicin (October 2024) was sequenced and a mutation was detected in rpoB causing an amino acid switch in RpoB (S531L). An amino acid switch in this position is a commonly described mechanism for rifampicin resistance.
4.3.6 Dogs
Escherichia coli
Isolates of Escherichia coli are from clinical submissions of urine from dogs, submitted either as urine, swab dipped in urine or cultures from dip-slides or other agar plates.
As in previous years, resistance to ampicillin was the most common trait in 2025, at 15% (Figure 4.11 and Table 4.27). Although the proportion of resistance in the tested isolates has varied somewhat between 2005 and 2025 there is still a slight decline in resistance for the four antibiotics ampicillin, enrofloxacin, nitrofurantoin and trimethoprim-sulphamethoxazole (Figure 4.11).
Eighty percent (679/846) of the isolates were susceptible to all the tested antibiotics, and the proportion of multiresistance was 4% (35/846). Fifty-one percent (18/35) of the multiresistant isolates were resistant to three antibiotics, 14% (5/35) to four, and 11% (4/35) to five antibiotics.
For comparison of resistance in E. coli of different origin see Chapter 5 - Comparative analysis. The most common phenotype, resistance to ampicillin, tetracycline and trimethoprim-sulphamethoxazole, was detected in 65% (23/35) of the multiresistant isolates. Of the eleven isolates resistant to four or more antibiotics, all but one had this phenotype.
Seventeen (2%) of the E. coli isolates were resistant to cefotaxime (MIC >0.25mg/L), and all were available for further testing. Genes conferring transferable ESC resistance were detected in four of the isolates. All four carried the gene blaCTX-M-15. For more information about ESBL-producing Enterobacterales isolated from dogs in Sweden, see Notifiable diseases, ESBL-producing Enterobacterales. One of the isolates was resistant to colistin (MIC >2mg/L) but negative in PCR analysis of the mcr-1 to mcr-9 genes. None of the isolates were resistant to meropenem (MIC>0.12mg/L).
| Antibiotic | Resistance (%) 2025 | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | 64 | >64 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Ampicillin | 15 | 2-16 | 8 | — | — | — | — | — | 42.3 | 38.7 | 3.5 | 0.2 | 15.2 | — | — |
| Cefalexin | 2 | 4-32 | 32 | — | — | — | — | — | — | 19.4 | 72.6 | 6.3 | 0.2 | 1.5 | — |
| Cefotaxim | 2a | 0.25-2 | 0.25 | — | — | 98.0 | 1.4 | 0.1 | — | 0.5 | — | — | — | — | — |
| Colistin | <1 | 1-8 | 2 | — | — | — | — | 99.1 | 0.8 | — | 0.1 | — | — | — | — |
| Enrofloxacin | 4 | 0.12-1 | 0.12 | — | 95.9 | 1.4 | 1.7 | 0.1 | — | — | 0.9 | — | — | — | — |
| Gentamicin | <1 | 2-16 | 2 | — | — | — | — | — | 99.1 | 0.2 | — | 0.4 | 0.4 | — | — |
| Meropenem | 0 | 0.06-0.25 | 0.12 | 99.9 | 0.1 | — | — | — | — | — | — | — | — | — | — |
| Neomycin | <1 | 4-32 | 8 | — | — | — | — | — | — | 98.9 | 0.2 | — | 0.1 | 0.7 | — |
| Nitrofurantoin | 0 | 32-64 | 64 | — | — | — | — | — | — | — | — | — | 99.8 | 0.2 | — |
| Tetracycline | 5 | 2-16 | 8 | — | — | — | — | — | 93.6 | 1.4 | — | 0.2 | 4.7 | — | — |
| Trim-Sulph.b | 7 | 0.5-4 | 0.5 | — | — | — | 92.6 | 0.8 | 0.2 | 0.1 | 6.3 | — | — | — | — |
| a All isolates (n=17) with MIC >0.25 mg/L were available for verification. Genes conferring transferable ESC resistance were detected in four of them. | |||||||||||||||
| b Concentration of trimethoprim given, tested in concentration ratio 1/20 (trimethoprim/sulphamethoxazole). | |||||||||||||||
Staphylococcus pseudintermedius
Isolates of Staphylococcus pseudintermedius are from clinical submissions of samples from skin lesions from dogs. Due to the implementation of an AMR panel for topical treatment (see Swedres Svarm 2022 In Focus p. 89, and Table 4.29) the number of isolates tested for systemic treatment has declined during 2023-2025.
Resistance to penicillin due to penicillinase production is high at 67% (Table 4.28), compared to other staphylococci in companion animals (Table 4.25 S. aureus in horses 25% and Table 4.33 S. felis in cats 13%). Although still high, the proportion of resistance to penicillin for isolates from skin lesions has declined from 90% in 2009 to 67% in 2025. Compared to penicillin, resistance to clindamycin and tetracycline remains at lower levels, and has also declined since 2007 (see previous Swedres-Svarm reports). The proportion of resistance to fusidic acid is not comparable before 2015 due to a change in the tested range of concentrations and cut-off. However, the proportion of resistance has declined snce 2015 (Table 4.28 and Figure 4.12). In 2025, a new cut-off was set for trimethoprim-sulphamethoxazole at 0.25 (compared to 0.5 earlier years), explaining the rise from 7% resistance in 2024 to 36% in 2025 (Table 4.28). Compared to other staphylococci isolated from companion animals, the proportion of resistance is high in the tested isolates. Only 25% (99/395) of the isolates were susceptible to all the tested antibiotics.
The proportion of multiresistance was 25% (97/395). This could be compared to 8% in S. aureus from horses and 2% in S. felis from cats. Fifty-nine percent (57/97) of the multiresistant isolates were resistant to three antibiotics; 21% (20/97) to four, 11% (11/97) to five and 4% (4/97) to six antibiotics. One isolate was resistant to nine antibiotics. The proportion of isolates resistant to five or more antibiotics has declined over the years. In 2016, almost one third of the multiresistant isolates were resistant to five or more antibiotics, compared to 14-22% in 2017-2024. In 2025, the proportion was 21% (20/97). Of the multiresistant isolates, resistance to penicillin, clindamycin and erythromycin was the most common phenotype at 55% (53/97).
Six of the isolates were resistant to oxacillin (MIC >0.25 mg/L). All were tested with PCR for detection of the mecA and mecC genes and all were positive for the mecA gene. For more information on MRSP isolated from dogs in Sweden, see Notifiable diseases, Methicillin-resistant Staphylococcus pseudintermedius. The isolates were screened for erythromycin-induced clindamycin resistance. Two isolates displayed such resistance.
| Antibiotic | Resistance (%) | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.03 | 0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | 64 | >64 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cefalexin | <1 | 1-4 | 4 | — | — | — | — | — | 70.6 | 27.3 | 1.3 | 0.8 | — | — | — | — |
| Cefoxitina | NA | 2-8 | NA | — | — | — | — | — | — | 98.2 | 1.0 | 0.3 | 0.5 | — | — | — |
| Clindamycin | 14b | 0.25-2 | 0.25 | — | — | — | 85.6 | 0.5 | 0.3 | 0.5 | 12.4 | — | — | — | — | — |
| Enrofloxacin | 3 | 0.25-1 | 0.5 | — | — | — | 94.4 | 3.0 | 0.8 | 1.8 | — | — | — | — | — | — |
| Erythromycin | 14 | 0.25-2 | 1 | — | — | — | 83.8 | 2.5 | — | — | 13.7 | — | — | — | — | — |
| Fusidic acid | 8 | 0.25-1 | 0.5 | — | — | — | 90.4 | 1.8 | — | 7.8 | — | — | — | — | — | — |
| Gentamicin | 5 | 1-4 | 2 | — | — | — | — | — | 95.4 | 0.3 | 0.3 | 4.1 | — | — | — | — |
| Nitrofurantoin | 0 | 16-64 | 32 | — | — | — | — | — | — | — | — | — | 99.7 | 0.3 | — | — |
| Oxacillin | 2c | 0.25-1 | 0.25 | — | — | — | 98.5 | 0.5 | — | 1.0 | — | — | — | — | — | — |
| Penicillin | 67d | 0.03-1 | NA | 35.4 | 7.1 | 5.3 | 11.9 | 8.6 | 9.6 | 22.0 | — | — | — | — | — | — |
| Tetracycline | 17 | 0.25-4 | 1 | — | — | — | 82.3 | 0.5 | 0.5 | — | — | 16.7 | — | — | — | — |
| Trim-Sulph.e | 36 | 0.25-4 | 0.25 | — | — | — | 64.3 | 26.8 | 3.5 | 0.3 | 0.3 | 4.8 | — | — | — | — |
| a No cut-off available for S. pseudintermedius. | ||||||||||||||||
| b Denotes resistance, including inducible resistance (2 isolates). | ||||||||||||||||
| c The six isolates with MIC>0.25 for oxacillin were tested with PCR for detection of the mecA and mecC genes, all were positive. | ||||||||||||||||
| d Denotes beta-lactamase production. | ||||||||||||||||
| e Concentration of trimethoprim given, tested in concentration ratio 1/20 (trimethoprim/sulphamethoxazole). | ||||||||||||||||
Susceptibility test for topical treatment
At SVA, it is possible to request antibiotic susceptibility testing of bacteria that is tailored for topical treatment. Both the antibiotics included in the test and the interpretation of the results differ from traditional testing for systemic treatment. The design of the panel for topical use covers substances included in veterinary medicinal products authorised for topical use and sold on veterinary prescription in Sweden, mainly for treatment of external ear and eye infections. In addition, some substances are included for the sole purpose of screening for methicillin resistance in coagulase positive staphylococci and ESBL in Enterobacterales.
It has been suggested by EUCAST that ECOFFs could be used to exclude acquired resistance to topical agents. They acknowledge that such an approach might underestimate the activity of the agents in some cases. However, it will at least demonstrate the presence of phenotypically detectable resistance mechanisms, which may result in a higher probability of clinical failure. Therefore, when bacteria are tested against substances for topical treatment at SVA, the breakpoints for interpretation are either EUCAST ECOFFs or, when no ECOFF is available, based on MIC distributions in Swedres-Svarm or other publications. As pharmacokinetic data have not been taken into consideration, the interpretation cannot be applied for systemic treatment.
Some combinations of antibiotic substance and bacterial species are not reported to the clinician for systemic treatment. For example, gentamicin for Pasteurella spp. or streptococci, and fusidic acid for streptococci. This is because it is not possible to reach therapeutic concentrations systemically against these bacteria, whereas the concentration at the site of the infection is much higher with topical treatment. Furthermore, some substances, such as chloramphenicol and tobramycin, are not tested for systemic treatment because they are only used for topical treatment. Occurrence of resistance varies among bacterial species and substances. However, in most cases, there are products available on the Swedish market that would be effective if topical antibiotic treatment is considered necessary. See In-focus - Sales of topical antimicrobial products).
Staphylococcus pseudintermedius - susceptibility test for topical treatment
Isolates of Staphylococcus pseudintermedius are from clinical submissions of samples from external ear canal from dogs in 2025.
Resistance to tetracycline (19%) was the most common trait in 2025, followed by neomycin (13%), chloramphenicol (10%) and fusidic acid (8%) (Table 4.29). The proportion of multiresistance was 4% (25/596). Sixty percent (15/25) of the multiresistant isolates were resistant to three antibiotics; 16% (4/25) to four, and 20% (5/25) to five. One isolate was resistant to six antibiotics. Of the multiresistant isolates, resistance to tetracycline, neomycin and chloramphenicol was the most common phenotype at 52% (13/25).
Four of the isolates were resistant to oxacillin (MIC >0.25 mg/L). All were tested with PCR for detection of the mecA and mecC genes, three were positive and one was negative. For more information on MRSP isolated from dogs in Sweden, see Notifiable diseases, Methicillin-resistant Staphylococcus pseudintermedius (MRSP).
| Antibiotic | Resistance (%) | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | >32 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cefoxitina | NA | 4-8 | NA | — | — | — | — | — | 99.2 | 0.5 | 0.2 | — | — |
| Enrofloxacin | 1 | 0.12-4 | 0.5 | 94.5 | 3.0 | 1.2 | 0.3 | 0.3 | 0.2 | 0.5 | — | — | — |
| Florfenicol | 0 | 1-16 | 8 | — | — | — | 4.5 | 90.3 | 5.0 | — | — | 0.2 | — |
| Fusidic acid | 8 | 0.25-1 | 0.5 | — | 91.1 | 1.0 | — | 7.9 | — | — | — | — | — |
| Gentamicin | 3 | 1-32 | 1 | — | — | — | 96.6 | 0.5 | 0.8 | 1.2 | 0.7 | 0.2 | — |
| Chloramphenicol | 10 | 2-16 | 16 | — | — | — | — | 1.5 | 81.0 | 7.1 | 0.7 | 9.7 | — |
| Neomycin | 13 | 2-8 | 2 | — | — | — | — | 87.4 | 3.4 | 6.0 | 3.2 | — | — |
| Oxacillin | 1b | 0.25-1 | 0.25 | — | 99.3 | 0.3 | — | 0.3 | — | — | — | — | — |
| Tetracycline | 19 | 1-8 | 1 | — | — | — | 81.4 | 0.5 | — | — | 18.1 | — | — |
| Tobramycin | 2 | 1-4 | 2 | — | — | — | 97.1 | 0.5 | 0.5 | 1.8 | — | — | — |
| a No cut-off available for S. pseudintermedius. | |||||||||||||
| b The four isolates with MIC >0.25 for oxacillin were tested with PCR for detection of the mecA and mecC genes, three were positive and one was negative. | |||||||||||||
Pseudomonas aeruginosa - susceptibility test for topical treatment
Isolates of Pseudomonas aeruginosa are from clinical submissions of samples from the external ear canal in dogs.
Pseudomonas aeruginosa is inherently resistant to trimethoprim-sulphonamides, tetracyclines and aminopenicillins (including combinations with clavulanic acid).
Resistance to enrofloxacin is the most common trait but the proportion of resistance to both enrofloxacin and gentamicin is still low (Table 4.30 and previous Swedres-Svarm reports). Three isolates were resistant to two antibiotics – gentamicin and tobramycin. One isolate was resistant to polymyxin B.
| Antibiotic | Resistance (%) 2024 | Resistance (%) 2025 | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | >32 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Enrofloxacin | 4 | 4 | 0.12-4 | 4 | 2.6 | 6.3 | 33.1 | 40.7 | 11.3 | 2.3 | 3.6 | — | — | — |
| Gentamicin | 1 | 1 | 1-32 | 8 | — | — | — | 34.8 | 45.0 | 14.9 | 4.3 | 0.7 | 0.3 | — |
| Polymyxin B | <1 | <1 | 1-4 | 4 | — | — | — | 77.5 | 20.9 | 1.3 | 0.3 | — | — | — |
| Tobramycin | 2 | 1 | 1-4 | 2 | — | — | — | 95.4 | 3.3 | 1.0 | 0.3 | — | — | — |
Pasteurella canis/oralis
Isolates of Pasteurella spp. are from clinical submissions of samples from various anatomical sites from dogs, mainly wounds (52%), abscesses (15%) and skin and external ear canal (11%).
Pasteurella canis/oralis was the most common Pasteurella sp. isolated in samples from dogs at 87% (328/378). The isolates were species identified with MALDI-TOF MS and P. canis and P. oralis cannot be separated by the method.
The cut-off values for Pasteurella multocida have been applied for all Pasteurella spp. Pasteurella spp. have a low inherent susceptibility to aminoglycosides, e.g. gentamicin. Not including gentamicin, 96% (273/283) of the isolates were susceptible to all antibiotics tested.
The proportion of resistance to enrofloxacin is generally low, with variations between <1% (2014), 4% (2020) and 2% (2025). Resistance to trimethoprim-sulphamethoxazole has been detected in one isolate each year 2020-2021. In 2022 it was detected in two isolates, in 2023 in seven isolates, in 2024 in six isolates and in 2025 in three isolates (Table 4.31 and previous Swedres-Svarm reports). Before 2020, all tested isolates were susceptible to trimethoprim-sulphamethoxazole (see previous Swedres-Svarm reports). Out of three resistant isolates, one was resistant to both enrofloxacin and trimethoprim-sulphamethoxazole, while the other two were resistant to trimethoprim-sulphamethoxazole only.
| Antibiotic | Resistance (%) | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.016 | 0.03 | 0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | >4 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Ampicillin | 0 | 0.06-1 | 0.5 | — | — | 91.9 | 8.1 | — | — | — | — | — | — |
| Enrofloxacin | 2 | 0.016-0.5 | 0.06 | 93.6 | 4.6 | — | 0.4 | 0.4 | 0.7 | 0.4 | — | — | — |
| Gentamicin | NR | 1-4 | NR | — | — | — | — | — | — | 95.8 | 3.5 | 0.7 | — |
| Penicillin | 0 | 0.03-1 | 0.5 | — | 59.4 | 39.2 | 1.4 | — | — | — | — | — | — |
| Tetracycline | 0 | 0.12-4 | 2 | — | — | — | 15.6 | 75.9 | 8.5 | — | — | — | — |
| Trim-Sulph.a | 1 | 0.03-1 | 0.12 | — | 96.5 | 2.1 | 0.4 | 0.4 | 0.4 | — | 0.4 | — | — |
| a Concentration of trimethoprim given, tested in concentration ratio 1/20 (trimethoprim/sulphamethoxazole). | |||||||||||||
4.3.7 Cats
Escherichia coli
Isolates are from clinical sampling of urine, submitted either as urine or cultures from dip-slides or other agar plates. As in previous years and in Escherichia coli isolated from dog urine (Table 4.27), resistance to ampicillin was the most common trait in 2025 (Table 4.32 and Figure 4.13). In comparison, in E. coli isolated from the genital tract of horses (mares), resistance to trimethoprim-sulphamethoxazole was most common (Table 4.23 and Figure 4.9). The proportions of resistance in the E. coli isolated from cat urine have differed somewhat throughout the years and trends are difficult to estimate (Figure 4.13).
| Antibiotic | Resistance (%) | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | 64 | >64 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Ampicillin | 19 | 2-16 | 8 | — | — | — | — | — | 50.7 | 29.2 | 1.2 | 0.7 | 18.2 | — | — |
| Cefalexin | 2 | 4-32 | 32 | — | — | — | — | — | — | 32.2 | 60.7 | 4.2 | 0.5 | 2.3 | — |
| Cefotaxime | 2a | 0.25-2 | 0.25 | — | — | 97.9 | 0.7 | 0.5 | 0.5 | 0.5 | — | — | — | — | — |
| Colistin | <1 | 1-8 | 2 | — | — | — | — | 99.3 | 0.5 | — | 0.2 | — | — | — | — |
| Enrofloxacin | 5 | 0.12-1 | 0.12 | — | 95.1 | 2.3 | 1.4 | — | 0.2 | — | 0.9 | — | — | — | — |
| Gentamicin | <1 | 2-16 | 2 | — | — | — | — | — | 99.8 | 0.2 | — | — | — | — | — |
| Meropenem | 0 | 0.06-0.25 | 0.12 | 100.0 | — | — | — | — | — | — | — | — | — | — | — |
| Neomycin | <1 | 4-32 | 8 | — | — | — | — | — | — | 99.1 | — | — | 0.2 | 0.7 | — |
| Nitrofurantoin | <1 | 32-64 | 64 | — | — | — | — | — | — | — | — | — | 99.3 | 0.5 | 0.2 |
| Tetracycline | 4 | 2-16 | 8 | — | — | — | — | — | 93.9 | 1.4 | 0.2 | 0.2 | 4.2 | — | — |
| Trim-Sulph.b | 3 | 0.5-4 | 0.5 | — | — | — | 97.0 | 0.2 | 0.5 | 0.2 | 2.1 | — | — | — | — |
| a Nine isolates with MIC >0.25mg/L were available for verification. A gene conferring transferable ESC resistance was detected in one of the isolates. | |||||||||||||||
| b Concentration of trimethoprim given, tested in concentration ratio 1/20 (trimethoprim/sulphamethoxazole). | |||||||||||||||
Seventy-six percent (324/428) of the E. coli isolates were susceptible to all the tested antibiotics. The proportion of multiresistance was 2% (10/428). Six of the multiresistant isolates were resistant to three antibiotics, two to four and two to five antibiotics. All of them were resistant to ampicillin and all but one were also resistant to trimethoprim-sulphamethoxazole. For comparison of resistance in E. coli of different origin, see Chapter 5 - Comparative analysis.
Nine of the E. coli isolates were resistant to cefotaxime (MIC >0.25 mg/L) and all were available for further testing. A gene conferring transferable ESC resistance was detected in one of the isolates (blaCTX-M-15). For more information on ESBL isolated from cats in Sweden, see Notifiable diseases, ESBL-producing Enterobacterales. One isolate was resistant to colistin (MIC >2mg/L) but was negative in PCR analysis of the mcr-1 to mcr-9 genes. No isolate was resistant to meropenem (MIC >0.12mg/L).
Staphylococcus felis
Isolates of Staphylococcus felis are from clinical submissions of samples from various anatomical sites, mainly abscesses and wounds (36%), the external ear canal (18%) and urine (29%) in cats.
The proportions of resistance to the tested antibiotics in isolates of S. felis (Table 4.33) were, as in previous years, lower than for S. pseudintermedius in dogs (Table 4.28 and previous Swedres-Svarm reports). Resistance to penicillin due to penicillinase production was 13% in S. felis, compared to 67% in S. pseudintermedius in dogs.
| Antibiotic | Resistance (%) | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.03 | 0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | 64 | >64 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cefalexin | 0 | 1-4 | 4 | — | — | — | — | — | 67.7 | 32.3 | — | — | — | — | — | — |
| Cefoxitina | NA | 2-8 | NA | — | — | — | — | — | — | 100.0 | — | — | — | — | — | — |
| Clindamycin | 5b | 0.25-2 | 0.25 | — | — | — | 94.6 | 1.6 | 0.3 | 0.3 | 2.9 | — | — | — | — | — |
| Enrofloxacin | 1 | 0.25-1 | 0.5 | — | — | — | 97.8 | 1.3 | 1.0 | — | — | — | — | — | — | — |
| Erythromycin | 5 | 0.25-2 | 0.5 | — | — | — | 70.6 | 24.6 | 1.0 | — | 3.8 | — | — | — | — | — |
| Fusidic acid | 1 | 0.25-1 | 0.5 | — | — | — | 97.8 | 1.3 | 0.6 | 0.3 | — | — | — | — | — | — |
| Gentamicin | <1 | 1-4 | 1 | — | — | — | — | — | 99.7 | 0.3 | — | — | — | — | — | — |
| Nitrofurantoin | 0 | 16-64 | 32 | — | — | — | — | — | — | — | — | — | 98.4 | 1.6 | — | — |
| Oxacillin | 0 | 0.25-1 | 1 | — | — | — | 100.0 | — | — | — | — | — | — | — | — | — |
| Penicillin | 13c | 0.03-1 | NA | 86.3 | 1.0 | 0.6 | 1.9 | 3.2 | 1.0 | 6.1 | — | — | — | — | — | — |
| Tetracycline | <1 | 0.25-4 | 1 | — | — | — | 98.4 | 1.3 | — | — | — | 0.3 | — | — | — | — |
| Trim-Sulph.d | 1 | 0.25-4 | 0.25 | — | — | — | 99.0 | 0.6 | 0.3 | — | — | — | — | — | — | — |
| a No cut-off available for S. felis. | ||||||||||||||||
| b Denotes resistance, including inducible resistance (2 isolates). | ||||||||||||||||
| c Denotes beta-lactamase production. | ||||||||||||||||
| d Concentration of trimethoprim given, tested in concentration ratio 1/20 (trimethoprim/sulphamethoxazole). | ||||||||||||||||
Eighty-one percent (252/313) of the S. felis isolates were susceptible to all the tested antibiotics. The proportion of multiresistance has varied between <1 and 7% during 2015-2024 (see previous Swedres-Svarm reports). In 2025, multiresistance was detected in 2% (6/313) of the isolates. The most common phenotype was resistance to penicillin, clindamycin and erythromycin (5/6). The isolates were screened for erythromycin-induced clindamycin resistance. Two isolates displayed such resistance.
Pasteurella multocida
Isolates of Pasteurella spp. are from clinical submissions of samples from various anatomical sites, but mainly from wounds or skin lesions, abscesses and the external ear canal (85%) in cats.
Pasteurella multocida was the most common Pasteurella sp. isolated in samples from cats at 93%. The proportion of resistance was low in the tested isolates except for trimethoprim-sulphamethoxazole (10%, Table 4.34).This is however a decrease from 16% in 2024 but an increase compared to 2022 (4%) and 2023 (6%).
No resistance to penicillin was detected. Pasteurella spp. have a low inherent susceptibility to aminoglycosides, e.g. gentamicin.
| Antibiotic | Resistance (%) | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.016 | 0.03 | 0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | >4 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Ampicillin | 0 | 0.06-1 | 0.5 | — | — | 1.6 | 11.2 | 80.0 | 7.2 | — | — | — | — |
| Enrofloxacin | <1 | 0.016-0.5 | 0.06 | 80.8 | 16.6 | 1.6 | 0.2 | 0.7 | — | — | — | — | — |
| Gentamicin | NR | 1-4 | NR | — | — | — | — | — | — | 0.7 | 3.7 | 67.1 | 28.4 |
| Penicillin | 0 | 0.03-1 | 0.5 | — | 1.4 | 12.8 | 72.0 | 13.5 | 0.2 | — | — | — | — |
| Tetracycline | 0 | 0.12-4 | 2 | — | — | — | 3.5 | 54.5 | 42.0 | — | — | — | — |
| Trim-Sulph.a | 10 | 0.03-1 | 0.12 | — | 44.5 | 37.8 | 7.5 | 2.8 | 2.8 | 1.2 | 3.5 | — | — |
| a Concentration of trimethoprim given, tested in concentration ratio 1/20 (trimethoprim/sulphamethoxazole). | |||||||||||||
Streptococcus canis/equisimilis (beta-haemolytic streptococci)
Isolates of Streptococcus canis/equisimilis are from clinical submissions of samples from various anatomical sites, but mainly (75%) from wounds/skin lesions and abscesses in cats. The isolates were species identified with MALDI-TOF MS and S. canis and S. equisimilis cannot be separated by the method. The same cut-offs as for Streptococcus equi subsp. zooepidemicus have been applied for the tested beta-haemolytic streptococci isolates.
Resistance data for beta-haemolytic streptococci isolated from cats were included in Swedres-Svarm 2011 (n=184), 2022 (n=128), 2023 (n=96), 2024 (n=94) and in 2025 (n=97). As in earlier years, all the tested isolates were susceptible to penicillin in 2025. (Table 4.35).
Any reduced susceptibility to penicillin in beta-hemolytic streptococci should be confirmed, i.e. if tested on pure culture and ensuring that organism identification and antimicrobial susceptibility test are accurate and reproducible.
The isolates were screened for erythromycin-induced clindamycin resistance. One isolate displayed such resistance.
Beta-haemolytic streptococci have a low inherent susceptibility to fluoroquinolones (e.g. enrofloxacin), aminoglycosides (e.g. gentamicin) and tetracyclines.
| Antibiotic | Resistance (%) | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.03 | 0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | 64 | >64 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cefalexin | 0 | 1-4 | 2 | — | — | — | — | — | 100.0 | — | — | — | — | — | — | — |
| Clindamycin | 8a | 0.25-2 | 0.5 | — | — | — | 91.8 | — | 1.0 | — | 7.2 | — | — | — | — | — |
| Enrofloxacin | NR | 0.25-1 | NR | — | — | — | 5.2 | 66.0 | 25.8 | 3.1 | — | — | — | — | — | — |
| Erythromycin | 9 | 0.25-2 | 0.25 | — | — | — | 90.7 | — | 1.0 | — | 8.2 | — | — | — | — | — |
| Gentamicin | NR | 1-4 | NR | — | — | — | — | — | 1.0 | 7.2 | 62.9 | 28.9 | — | — | — | — |
| Nitrofurantoin | 0 | 16-64 | 32 | — | — | — | — | — | — | — | — | — | 100.0 | — | — | — |
| Penicillin | 0 | 0.03-1 | 0.03 | 100.0 | — | — | — | — | — | — | — | — | — | — | — | — |
| Tetracycline | NR | 0.25-4 | NR | — | — | — | 3.1 | 1.0 | 1.0 | 26.8 | 46.4 | 21.6 | — | — | — | — |
| Trim-Sulph.b | 0 | 0.25-4 | 0.5 | — | — | — | 99.0 | 1.0 | — | — | — | — | — | — | — | — |
| a Denotes resistance, including isolates with inducible resistance (1 isolate). | ||||||||||||||||
| b Concentration of trimethoprim given, tested in concentration ratio 1/20 (trimethoprim/sulphamethoxazole). | ||||||||||||||||
4.4 Indicator bacteria from animals
In veterinary antibiotic resistance surveillance programmes, Escherichia coli, Enterococcus faecalis and Enterococcus faecium, isolated from the enteric flora of healthy animals or from contaminated food, serve as indicators of the presence of acquired resistance. The level of resistance in these so-called indicator bacteria reflects the magnitude of the selective pressure from antibiotic use in an animal population. Moreover, although these bacteria are unlikely to cause disease, they can be reservoirs for resistance genes that may spread to bacteria pathogenic to animals or humans. Resistance in indicator bacteria contaminating meat indicates the potential exposure of humans through the food chain.
During 2025, indicator E. coli was studied in fattening pigs and horses, and in pig and cattle meat samples.
Samples from fattening pigs were collected at slaughter under the supervision of the National Food Agency (SLV) at six abattoirs that together processed more than 85% of the total number of pigs slaughtered in Sweden during 2025. The number of samples from each abattoir was roughly proportional to their annual slaughter volume, and the sampling was distributed over the year. Each sample was randomly selected but represented a unique herd per day. Samples were sent to SVA for culture on the day of collection or the following day and were kept refrigerated in the meantime.
Samples from horses were sent to SVA for analyses of intestinal parasites in the spring of 2025. The exact samples analysed were selected at random from all samples sent to SVA.
Samples of meat originating from outside the EU were collected at border control posts under the supervision of the National Food Agency (SLV). All approved border control posts were engaged in the sampling, and at each post the first eligible meat sample of each meat category was sampled. Thereafter, a predefined number of consignments, based on numbers from previous years, were randomly selected for sampling. The exact meat lots to be sampled were randomly selected by the sampling personnel at the border control posts. Samples were kept refrigerated before being sent to SVA for culture on the day of collection or the following day.
All samples analysed for indicator E. coli from pigs and pig and cattle meat were also screened for ESC-resistant E. coli using selective culture on cefotaxime-supplemented media. For details on the methodology see Chapter 6 - Material and methods, Resistance in bacteria from animals.
4.4.1 Escherichia coli
Pigs
In 2025, Escherichia coli was isolated from 172 (97%) of 177 cultured caecal samples from pigs. The majority of the isolates (68%) were susceptible to all tested antibiotics (Table 4.36). Resistance to ampicillin (21%), sulphonamides (19%), trimethoprim (16%) and tetracycline (15%) were the most common traits (Table 4.37 and Table 4.38). Thirty-one isolates (18%) were multiresistant, i.e. resistant to three or more antibiotics, with ciprofloxacin and nalidixic acid as well as cefotaxime and ceftazidime considered as one antibiotic class (Table 4.36 and Figure 4.14). Of these, all but one (97%) had resistance to sulphonamides in their phenotype, 78% had resistance to ampicillin, 72% had resistance to trimethoprim and 33% had resistance to tetracyclines.
| Resistance (%) to 0->3 antibioticsa | Broilers (2024, n=173) | Cattle (2020-21, n=101)b | Laying hens (2021-22, n=110) | Pigs (2025, n=172) | Sheep (2006-09, n=115) | Turkeys (2024, n=29) | Dogs (2012, n=74) | Horses (2025, n=160) |
|---|---|---|---|---|---|---|---|---|
| Susceptible to all | 79 | 95 | 88 | 68 | 89 | 90 | 84 | 87 |
| Resistant to 1 | 13 | 4 | 8 | 12 | 8 | 7 | 8 | 8 |
| Resistant to 2 | 1 | 2 | 2 | 2 | 3 | 3 | 7 | 6 |
| Resistant to 3 | 4 | — | 2 | 10 | <1 | — | — | 0 |
| Resistant to >3 | 3 | — | — | 8 | — | — | <1 | 1 |
| a Ciprofloxacin and nalidixic acid as well as cefotaxime and ceftazidime were considered as one antibiotic class. | ||||||||
| b Cattle older than 6 months. | ||||||||
| Antibiotic | ECOFF (mg/L) | Broilers (2024, n=173) | Cattle (2020-21, n=101)a | Laying hens (2021-22, n=110) | Pigs (2025, n=172) | Sheep (2006-09, n=115) | Turkeys (2024, n=29) | Dogs (2012, n=74) | Horses (2025, n=160) |
|---|---|---|---|---|---|---|---|---|---|
| Amikacin | >8 | 1 | 0 | 0 | 1 | - | 0 | - | 1 |
| Ampicillin | >8 | 11 | 2 | 3 | 21 | 2 | 3 | 9 | 5 |
| Azithromycin | >16 | 0 | 0 | 0 | <1 | - | 0 | - | 0 |
| Cefotaxime | >0.25 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 |
| Ceftazidime | >1 | 0 | 0 | 0 | 0 | - | 0 | - | 0 |
| Chloramphenicol | >16 | 0 | 0 | 1 | 5 | 0 | 0 | 0 | 1 |
| Ciprofloxacin | >0.06 | 7 | 0 | 2 | 0 | <1 | 0 | 3 | 0 |
| Colistin | >2 | 0 | 0 | 0 | 0 | - | 0 | 0 | <1 |
| Gentamicin | >2 | 1 | 0 | 0 | <1 | 3 | 3 | 0 | 0 |
| Meropenem | >0.12 | 0 | 0 | 0 | 0 | - | 0 | - | 0 |
| Nalidixic acid | >8 | 7 | 0 | 2 | 0 | 0 | 0 | 0 | 0 |
| Sulphamethoxazole | >64 | 11 | 2 | 3 | 19 | 7 | 3 | 4 | 5 |
| Tetracycline | >8 | 3 | 2 | 5 | 15 | <1 | 0 | 8 | 2 |
| Tigecycline | >0.5 | 0 | 0 | 0 | 0 | - | 0 | - | 0 |
| Trimethoprim | >2 | 8 | 2 | 4 | 16 | 2 | 3 | 1 | 5 |
| a Cattle older than 6 months. | |||||||||
| Antibiotic | Resistance % | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.016 | 0.03 | 0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | 64 | 128 | 256 | 512 | >512 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Amikacin | 1 | 4–128 | 8 | — | — | — | — | — | — | — | — | 93.0 | 5.8 | 1.2 | — | — | — | — | — | — |
| Ampicillin | 21 | 1–32 | 8 | — | — | — | — | — | — | 4.1 | 35.5 | 35.5 | 4.1 | — | — | 20.9 | — | — | — | — |
| Azithromycin | <1 | 2–64 | 16 | — | — | — | — | — | — | — | 15.1 | 40.1 | 37.8 | 6.4 | — | — | 0.6 | — | — | — |
| Cefotaxime | 0 | 0.25–4 | 0.25 | — | — | — | — | 100.0 | — | — | — | — | — | — | — | — | — | — | — | — |
| Ceftazidime | 0 | 0.25–8 | 1 | — | — | — | — | 97.7 | 2.3 | — | — | — | — | — | — | — | — | — | — | — |
| Chloramphenicol | 5 | 8–64 | 16 | — | — | — | — | — | — | — | — | — | 94.8 | 0.6 | 1.2 | 1.2 | 2.3 | — | — | — |
| Ciprofloxacin | 0 | 0.015–8 | 0.06 | 91.9 | 8.1 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Colistin | 0 | 1–16 | 2 | — | — | — | — | — | — | 100.0 | — | — | — | — | — | — | — | — | — | — |
| Gentamicin | <1 | 0.5–16 | 2 | — | — | — | — | — | 70.9 | 23.3 | 5.2 | — | — | — | 0.6 | — | — | — | — | — |
| Meropenem | 0 | 0.03–16 | 0.12 | — | 98.3 | 1.7 | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Nalidixic acid | 0 | 4–64 | 8 | — | — | — | — | — | — | — | — | 99.4 | 0.6 | — | — | — | — | — | — | — |
| Sulphamethoxazole | 19 | 8–512 | 64 | — | — | — | — | — | — | — | — | — | 52.3 | 27.9 | — | 0.6 | — | — | — | 19.2 |
| Tetracycline | 15 | 2–32 | 8 | — | — | — | — | — | — | — | 84.9 | — | — | — | 1.7 | 13.4 | — | — | — | — |
| Tigecycline | 0 | 0.25–8 | 0.5 | — | — | — | — | 98.8 | 1.2 | — | — | — | — | — | — | — | — | — | — | — |
| Trimethoprim | 16 | 0.25–16 | 2 | — | — | — | — | 58.7 | 23.8 | 1.2 | — | — | — | — | 16.3 | — | — | — | — | — |
From an international perspective, levels of resistance in E. coli from pigs are low in Sweden. The proportion of isolates susceptible to all tested antibiotics has been relatively stable in recent years (68% in 2015, 71% in 2017, 71% in 2019, 64% in 2021, 73% in 2023 and 68% in 2025). However, for some substances, the situation has become less favourable (Figure 4.15). More specifically, the occurrence of resistance to ampicillin, sulphonamides and trimethoprim in E. coli from pigs has increased considerably since 2008, and the occurrence of resistance to tetracycline has increased since 2017.
Regarding substances in category B (“Restrict”) of the AMEG classification (European Medicines Agency (EMA) 2025), resistance to polymyxins (colistin) has been tested for since 2011 but has never been detected (Figure 4.15). Resistance to quinolones and third-generation cephalosporins (ceftiofur 2000-2005, cefotaxime 2005-2012, and cefotaxime as well as ceftazidime from 2013 onwards) has remained stable at low rates. In 2025, none of the isolates were resistant to cefotaxime or ceftazidime.
However, using the more sensitive selective culture method, ESC-resistant E. coli was isolated from six (2%) of 301 samples. In five of these isolates (2%), transferable genes for resistance to ESC were found. Two isolates had the blaCTX-M-15 gene, one the blaCTX-M-14 gene, one the blaCTX-M-55 gene and one the blaSHV-12 gene. The remaining isolate had an AmpC phenotype and genome sequencing of these isolates revealed mutations causing hyper-production of AmpC beta-lactamases, i.e. a shift from C to T at position 42. For more details and comments on occurrence of resistance to ESC, see Antibiotic resistance in animals, Notifiable diseases.
Horses
In 2025, Escherichia coli was isolated from 160 (89%) of 180 cultured caecal samples from horses. The majority of the isolates (87%) were susceptible to all tested antibiotics (Table 4.36). Resistances to ampicillin (5%), sulphonamides (5%) and trimethoprim (5%) were the most common traits (Table 4.37 and Table 4.39). One isolate (<1%) was multiresistant, i.e. resistant to three or more antibiotics (Table 4.36). It was resistant to ampicillin, chloramphenicol, sulphonamides, tetracyclines and trimethoprim.
| Antibiotic | Resistance % | Tested range (mg/L) | Cut-off value (mg/L) | ≤0.016 | 0.03 | 0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | 64 | 128 | 256 | 512 | >512 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Amikacin | 1 | 4–128 | 8 | — | — | — | — | — | — | — | — | 88.1 | 10.6 | 0.6 | — | 0.6 | — | — | — | — |
| Ampicillin | 5 | 1–32 | 8 | — | — | — | — | — | — | 0.6 | 15.0 | 56.9 | 22.5 | 1.3 | 0.6 | 3.1 | — | — | — | — |
| Azithromycin | 0 | 2-64 | 16 | — | — | — | — | — | — | — | 43.8 | 42.5 | 11.9 | 1.9 | — | — | — | — | — | — |
| Cefotaxime | 0 | 0.25-4 | 0.25 | — | — | — | — | 100.0 | — | — | — | — | — | — | — | — | — | — | — | — |
| Ceftazidime | 0 | 0.25–8 | 1 | — | — | — | — | 99.4 | 0.6 | — | — | — | — | — | — | — | — | — | — | — |
| Chloramphenicol | 1 | 8–64 | 16 | — | — | — | — | — | — | — | — | — | 98.1 | 0.6 | — | — | 1.3 | — | — | — |
| Ciprofloxacin | 0 | 0.015–8 | 0.06 | 98.8 | 0.6 | 0.6 | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Colistin | <1 | 1–16 | 2 | — | — | — | — | — | — | 99.4 | — | — | 0.6 | — | — | — | — | — | — | — |
| Gentamicin | 0 | 0.5–16 | 2 | — | — | — | — | — | 70.0 | 25.6 | 4.4 | — | — | — | — | — | — | — | — | — |
| Meropenem | 0 | 0.03–16 | 0.12 | — | 99.4 | 0.6 | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Nalidixic acid | 0 | 4–64 | 8 | — | — | — | — | — | — | — | — | 98.8 | 1.3 | — | — | — | — | — | — | — |
| Sulphamethoxazole | 5 | 8–512 | 64 | — | — | — | — | — | — | — | — | — | 83.8 | 10.6 | 0.6 | — | — | — | — | 5.0 |
| Tetracycline | 2 | 2–32 | 8 | — | — | — | — | — | — | — | 86.9 | 10.6 | 0.6 | — | — | 1.9 | — | — | — | — |
| Tigecycline | 0 | 0.25–8 | 0.5 | — | — | — | — | 100.0 | — | — | — | — | — | — | — | — | — | — | — | — |
| Trimethoprim | 5 | 0.25–16 | 2 | — | — | — | — | 83.1 | 11.9 | — | — | — | — | — | 5.0 | — | — | — | — | — |
Meat
Escherichia coli was isolated from two of twelve cattle meat samples collected at the border control posts, whereas none of the three pig meat samples were positive. The detected E. coli isolates originated from two of four sampled cattle meat consignments. Both isolates from cattle meat were susceptible to all tested antibiotics.
This was the third time that the occurrence of resistance among indicator E. coli from meat sampled at border control posts was assessed in Svarm. Although little resistance has been detected thus far, the small number of recovered isolates each year limits the conclusions that can be drawn from these results. None of the isolates were resistant to cefotaxime or ceftazidime. Using a more sensitive selective culture method with cefotaxime in the agar, ESC-resistant E. coli was isolated from one sample of fresh cattle and pig meat. The isolates carried the blaCTX-M-27 and blaDHA-1 genes, respectively. For more details and comments on occurrence of resistance to ESC, see Antibiotic resistance in animals, Notifiable diseases.