Building the European Antimicrobial Resistance Surveillance network in veterinary medicine (EARS-Vet).

Antimicrobial resistance (AMR) should be tackled through a One Health approach, as stated in the World Health Organization Global Action Plan on AMR. We describe the landscape of AMR surveillance in the European Union/European Economic Area (EU/EEA) and underline a gap regarding veterinary medicine. Current AMR surveillance efforts are of limited help to veterinary practitioners and policymakers seeking to improve antimicrobial stewardship in animal health. We propose to establish the European Antimicrobial Resistance Surveillance network in Veterinary medicine (EARS-Vet) to report on the AMR situation, follow AMR trends and detect emerging AMR in selected bacterial pathogens of animals. This information could be useful to advise policymakers, explore efficacy of interventions, support antimicrobial stewardship initiatives, (re-)evaluate marketing authorisations of antimicrobials, generate epidemiological cut-off values, assess risk of zoonotic AMR transmission and evaluate the burden of AMR in animal health. EARS-Vet could be integrated with other AMR monitoring systems in the animal and medical sectors to ensure a One Health approach. Herein, we present a strategy to establish EARS-Vet as a network of national surveillance systems and highlight challenges of data harmonisation and bias. Strong political commitment at national and EU/EEA levels is required for the success of EARS-Vet.

Occurrence and Spread of Quinolone-Resistant Escherichia coli on Dairy Farms.

UNLABELLED: Quinolone-resistant Escherichia coli (QREC) is common in feces from young calves, but the prevalence and genetic diversity of QREC in groups of cattle of other ages and the farm environment are unknown. The aims of the study were to obtain knowledge about the occurrence of QREC on dairy farms, the genetic diversity of QREC within and between farms, and how these relate to the number of purchased animals and geographic distances between farms. We analyzed the within-sample prevalence of QREC in individual fecal samples from preweaned dairy calves and postpartum cows and in environmental samples from 23 Swedish dairy farms. The genetic diversity of the QREC isolates on 10 of these farms was assessed. In general, QREC was more prevalent in the dairy farm environment and in postpartum cows if QREC was commonly found in calves than if QREC was rare in calves. In particular, we found more QREC organisms in feed and water troughs and in environments that may come into contact with young calves. Thus, the results suggest that QREC circulates between cattle and the farm environment and that calves are important for the maintenance of QREC. Some genotypes of QREC were widespread both within and between farms, indicating that QREC has spread within the farms and likely also between farms, possibly through purchased animals. Farms that had purchased many animals over the years had greater within-farm diversity than farms with more closed animal populations. Finally, animals on more closely located farms were more likely to share the same genotype than animals on farms located far apart. IMPORTANCE: This study investigates the occurrence of a specific type of antimicrobial-resistant bacterium on dairy farms. It contributes to increased knowledge about the occurrence and spread of these bacteria, and the results pave the way for actions or further studies that could help mitigate the spread of these bacteria on dairy farms and in the community as a whole.

Risk factors for antimicrobial resistance in fecal Escherichia coli from preweaned dairy calves.

The primary objective of this study was to investigate calf and farm factors associated with antimicrobial-resistant Escherichia coli in the feces of preweaned dairy calves in Sweden. In particular, we investigated the effects of feeding calves colostrum and milk from cows treated with antimicrobials. The secondary objective was to describe the prevalence of resistant E. coli in feces of preweaned dairy calves in Sweden. Fecal samples from 3 calves, aged 7 to 28d, from 243 farms were analyzed for the within-sample prevalence of E. coli resistant to nalidixic acid, streptomycin, and cefotaxime using selective agars supplemented with antimicrobials. In addition, resistance to 12 antimicrobials was tested in one randomly selected E. coli isolate per calf. Information was collected from the farmers via questionnaires regarding the use of colostrum and milk from cows treated with antimicrobials as calf feed and other uses of antimicrobials in the herd. Multivariable zero-inflated negative binomial and logistic regression models were used to assess the effect of various risk factors for shedding of resistant E. coli. Escherichia coli resistant to streptomycin, nalidixic acid, or cefotaxime were isolated from 90, 49, and 11% of the calves, respectively. Resistance to at least one antimicrobial was found in a random isolate of E. coli from 48% of the calves. Feeding colostrum from cows treated with antimicrobials at drying off did not affect the prevalence of resistant E. coli. In contrast, feeding milk from cows treated with antimicrobials during lactation resulted in significantly more nalidixic acid- and streptomycin-resistant E. coli than when such milk was discarded; no significant effect was seen for other resistance traits. Furthermore, an interaction was found between feeding milk from cows treated with antimicrobials and use of fluoroquinolones in cows. In general, the prevalence of resistance was lower for older calves and calves on small farms. Other factors that were associated with the shedding of resistant E. coli were administration of oral dihydrostreptomycin to calves, administration of systemic tetracycline and ceftiofur to cows and calves, housing of the calves, predominant breed of the herd, and geographic location of the farm. The presence of resistant E. coli in calves was clearly due to multiple factors, but minimizing the feeding of milk from cows treated with antimicrobials during lactation should lower the prevalence of resistant E. coli in the gastrointestinal tract of the calves.

Risk factors for quinolone-resistant Escherichia coli in feces from preweaned dairy calves and postpartum dairy cows.

Quinolone resistance may emerge in gut bacteria (e.g., in Escherichia coli) of animals. Such bacteria could cause infections in the animal itself or be transmitted to humans via the food chain. Quinolone resistance is also observed in fecal E. coli of healthy dairy cattle, but the prevalence varies between farms, not solely as a result of varying degree of fluoroquinolone exposure. The objective of this study was to identify risk factors for the fecal shedding of quinolone-resistant E. coli (QREC) from dairy calves and postpartum cows. Rectal swabs from 15 preweaned calves and 5 postpartum cows per farm were collected on 23 Swedish dairy farms to determine the prevalence of QREC. Risk factors for the shedding of QREC were investigated using multivariable statistical models. Quinolone-resistant E. coli were found on all but one farm. Factors associated with QREC shedding by calves were being younger than 18 d, being fed milk from cows treated with antimicrobials, recent use of fluoroquinolones in the herd, carriage of QREC by postpartum cows, and using the calving area never or rarely as a sick pen compared with often. Factors associated with QREC shedding by cows were calving in group pens or freestalls compared with single pens or tiestalls, purchasing cattle, sharing animal transports with other farmers, and poor farm hygiene. Proper biosecurity and improved hygiene, as well as minimizing fluoroquinolone exposure and waste milk feeding, may be important factors to reduce the burden of QREC on dairy farms.

Vertical transmission of Escherichia coli carrying plasmid-mediated AmpC (pAmpC) through the broiler production pyramid.

OBJECTIVES: In Sweden the prevalence of Enterobacteriaceae with transferable resistance to extended-spectrum cephalosporins (ESCs) is low. However, in broilers ESC-resistant Escherichia coli is common, with a clear dominance of blaCMY-2. Antimicrobials are rarely used in broiler production in Sweden and cephalosporins are never used. Introduction through imported breeding stock and subsequent vertical transmission of the bacteria through the production pyramid could be one explanation for this high prevalence. METHODS: To test this hypothesis, paper linings from imported flocks of grandparent animals were screened for the presence of ESC-resistant E. coli and a positive flock, together with its progeny, was followed longitudinally through the production pyramid using boot swabs. The relationship of isolated ESC-resistant E. coli was investigated using multiple-locus variable number tandem repeat analysis (MLVA). RESULTS: ESC-resistant E. coli carrying blaCMY-2 was isolated from six out of eight imported flocks of grandparent animals. One clone of E. coli carrying blaCMY-2 occurred in all levels of the production pyramid and in flocks of imported grandparent animals. CONCLUSIONS: E. coli carrying blaCMY-2 is frequently present among grandparent animals imported to Sweden for breeding purposes. The occurrence of one clone in all levels of the production pyramid indicates that its introduction through imported breeding stock and vertical transmission through the production pyramid could be one explanation for the high proportion of Swedish broilers colonized with ESC-resistant E. coli.

Characterisation of bacterial growth and antimicrobial susceptibility patterns in canine urinary tract infections.

BACKGROUND: Bacterial urinary tract infection (UTI) is a common reason for antimicrobial therapy in dogs. A reported increase in multi-drug resistance in canine bacterial pathogens, including resistance to extended-spectrum cephalosporins (ESC) is of concern as antimicrobial resistance complicates therapy in dogs. In addition, it is a possible public health concern. The objectives of this study were to investigate the relative prevalence of pathogens in urine samples from dogs with urinary tract infection sampled at referral hospitals, clinics and mixed veterinary practices and to investigate if this was influenced by sample material or by contamination of the culture. The second objective was to assess the susceptibility patterns to clinically relevant antimicrobials and to investigate if this was influenced by whether the samples originated from smaller clinics or from referral hospitals and to perform active screening for the presence of Enterobacteriaceae resistant to ESC. RESULTS: Escherichia coli was the most frequently isolated pathogen (68%) followed by staphylococci (11%). E. coli isolates were found significantly more often in pure culture than in contaminated samples. Staphylococcus pseudintermedius and Staphylococcus aureus isolates were significantly more prevalent in pre-incubated samples compared to samples submitted as non-incubated media. Susceptibility to the majority of the tested first-line antimicrobials was common. Multiresistance was rare, and these isolates were all susceptible to at least one relevant antimicrobial. Isolates in samples from small animal clinics or mixed veterinary practices were less likely to be susceptible compared to isolates originating from referral animal hospitals. ESC-resistant Enterobacteriacae isolates were found in one per cent of the positive cultures. Bacteria with transferable ESC resistance were confirmed in one dog. The gene demonstrated was bla CMY2. CONCLUSIONS: Choice of sample material might influence the possibility of detecting Staphylococcus pseudintermedius and Staphylococcus aureus isolates in clinical cases of UTI in dogs. Based on the study results, use of first-line antimicrobials is a rational empirical antimicrobial therapy for the studied dog population. E. coli was the most prevalent pathogen, but prevalence of infection with ESC resistant Enterobacteriaceae including E. coli was low, as such isolates were found in only one per cent of the positive cultures.

Successful Prevention of Antimicrobial Resistance in Animals-A Retrospective Country Case Study of Sweden.

The misuse and overuse of antibiotics have resulted in an alarmingly high prevalence of antimicrobial resistance (AMR) in human and animal bacteria. European monitoring programmes show that AMR occurrence in food animals is lower in Sweden than in most other EU Member States and that the use of antibiotics for animals is among the lowest in Europe. In this retrospective country case study, we analysed published documents to identify factors contributing to this favourable situation. A fundamental factor identified was early insight into and sustained awareness of the risks of AMR and the need for the prudent use of antibiotics. Early and continuous access to data on antibiotic use and AMR made it possible to focus activities on areas of concern. Another factor identified was the long-term control and eradication of infectious animal diseases, including coordinated activities against endemic diseases, which reduced the need to use antibiotics. Structures and strategies for that purpose established at the national level have since proven useful in counteracting AMR as an integral part of disease prevention and control, guided by a "prevention is better than cure" approach. A third factor identified was consensus among stakeholders on the need to address AMR and their cooperation in the design and implementation of measures.

Associations between Bovine Coronavirus and Bovine Respiratory Syncytial Virus Infections and Productivity, Health Status and Occurrence of Antimicrobial Resistance in Swedish Dairy Herds.

Bovine respiratory syncytial virus (BRSV) and bovine coronavirus (BCoV) affect dairy herds worldwide. In this study, effects on herd health, morbidity, and antimicrobial resistance (AMR) were assessed. Herds were considered free of infection (FREE), recently infected (RI) or past steadily infected (PSI) based on antibody testing of milk from primiparous cows. Data from farm records, national databases, and AMR of fecal Escherichia coli from calves were used as outcome variables. Compared to BRSV FREE herds: BRSV PSI herds had significantly higher odds of cough in young stock, a higher proportion of quinolone-resistant E. coli (QREC), but a lower proportion of cows with fever. BRSV RI herds had significantly higher odds of diarrhea in calves and young stock, a higher proportion of QREC and higher odds of multidrug-resistant E. coli. Compared to BCoV FREE herds: BCoV PSI herds had significantly higher odds of cough in all ages, and of diarrhea in young stock and cows, and a higher proportion of cows with fever. BCoV RI herds had significantly higher odds of diarrhea in young stock and cows and of cough in all ages. The results support previous research that freedom from BRSV and BCoV is beneficial for animal welfare and farm economy and possibly also mitigates AMR.

A Pilot Study in Sweden on Efficacy of Benzylpenicillin, Oxytetracycline, and Florfenicol in Treatment of Acute Undifferentiated Respiratory Disease in Calves.

Bovine respiratory disease (BRD) is a major indication for antibiotic treatment of cattle worldwide and some of the antibiotics used belong to classes of highest priority among those listed by WHO as critically important for human medicine. To preserve the efficacy of "newer" antibiotics, it has been suggested that "older" drugs should be revisited and used when possible. In this pilot study, we evaluated the efficacy of benzylpenicillin (PEN), oxytetracycline (OTC), and florfenicol (FLO) for treatment of naturally occurring BRD on two farms raising calves for slaughter. Farm personnel selected calves for enrolment, assigned calves to one of the three regimens in a systematically random manner, treated the calves, and registered the results. Overall, 117 calves were enrolled in the study. Nineteen calves relapsed in BRD before slaughter and were retreated (16.2%) and three died (2.6%). For PEN, treatment response rates after 30 days, 60 days, and until slaughter were 90.2%, 87.8%, and 80.5%, respectively; for OTC, 90.0%, 85.0%, and 85.0%, respectively; and for FLO, 86.1%, 83.3%, and 77.8%, respectively. There were no statistically significant differences in relapse, mortality, or response rates between the three treatment regimens. This indicates that PEN, OTC, and FLO were equally effective for treatment of BRD but the results need to be confirmed in a more elaborate study with a higher statistical power. The findings support the current recommendations from the Swedish Veterinary Association and the Medical Products Agency to use benzylpenicillin as a first line antibiotic for treatment of calves with undifferentiated respiratory disease in Sweden. Due to differences in the panorama of infectious agents and presence of acquired antibiotic resistance, the findings might not be applicable in other geographical areas.

Decreased detection of ESBL- or pAmpC-producing Escherichia coli in broiler breeders imported into Sweden.

In the spring of 2010, it was discovered that a large proportion of broilers in Sweden were colonized with Escherichia coli producing extended-spectrum beta-lactamases (ESBL) or plasmid mediated AmpC (pAmpC). It was hypothesized that the high prevalence was due to transfer from an upper level in the production pyramid and sampling upwards in the production pyramid was initiated. From 2010 to 2019, all shipments (n = 122) of broiler breeders were screened on arrival to Sweden for the occurrence of ESBL- or pAmpC-producing E. coli using selective methods. Samples of paper linings from shipments of breeders were cultured on MacConkey agar supplemented with cefotaxime (1 mg/L) after pre-enrichment in either MacConkey broth with cefotaxime (1 mg/L), or from late June 2015 in buffered peptone water without antibiotics. ESBL- or pAmpC-producing E. coli was isolated from 43 (35%) of these. Over the years, the proportion of positive imports have decreased and during 2018 and 2019 all imports were negative. In conclusion, the occurrence of ESBL- or pAmpC-producing E. coli in broiler breeders on arrival to Sweden has decreased. Such bacteria have not been detected in any shipments since 2017.

Exposure to benzylpenicillin after different dosage regimens in growing pigs.

BACKGROUND: Penicillin is important for treatment of pigs, but data on its absorption and disposition in pigs are sparse. This is reflected by the variation in recommended dosages in the literature. Inadequate dosage may lead to treatment failure and selection of resistant bacteria. To optimize treatment regimens, plasma exposure to benzylpenicillin for two sustained release formulations of procaine benzylpenicillin for intramuscular administration was studied in growing pigs by means of tandem mass spectrometry (UPLC-MS/MS). One formulation was an aqueous suspension, Ethacilin® vet (ETH), and the other an oily suspension, Ultrapen vet (UPA). Benzylpenicillin exposure after intravenous administration of potassium benzylpenicillin was also explored. Exposure profiles were first studied after single administrations of the approved dosages in healthy pigs and then after repeated administration of different dosages in pigs inoculated intranasally with an Actinobacillus pleuropneumoniae serotype 2 strain. RESULTS: After intravenous administration of benzylpenicillin (n = 6), maximum plasma concentration (Cmax), 1860-9318 µg/L, was observed after 15 min. At four h, plasma concentrations decreased to 15-76 µg/L. After intramuscular administration of ETH (n = 6) Cmax, 1000-4270 µg/L, was observed within one h (tmax) in 5 pigs but at four h in one pig. Cmax for UPA (n = 6), 910-3220 µg/L, was observed within one h in three pigs, but at four or 24 h in three pigs. For both ETH and UPA, the terminal phase was characterized by slow decline compared with intravenous administration. Repeated administration of different dosages of ETH and UPA in pigs inoculated with A. pleuropneumoniae (n = 54) showed that the approved dose for UPA (30 mg/kg, qd) but not for ETH (20 mg/kg, qd) gave adequate plasma exposure for bacteria with a penicillin MIC of 500 µg/L. However, more frequent dosing of ETH (bid) or increased dosage gave an adequate exposure. CONCLUSIONS: The approved dosage of ETH provided insufficient plasma exposure for adequate therapy of infections caused by A. pleuropneumoniae or other bacteria with a penicillin MIC of 500 µg/L. More frequent ETH dosing (bid) or an increased dosage would improve exposure. The approved dosage of UPA however provided adequate exposure.

Incidence of mastitis and bacterial findings at clinical mastitis in Swedish primiparous cows- influence of breed and stage of lactation.

Mastitis is a common disease also among primiparous dairy cows. Identification of the extent and type of problem is important to initiate correct control measures. In Sweden, unique national production and disease databases are available. The main aim of the study was to investigate the occurrence of mastitis, measured by the annual incidence of veterinary-treated clinical mastitis (VTCM) and geometric mean of monthly milk somatic cell count (SCC) recordings in Swedish primiparous cows in relation to older cows during 2002-2006 with emphasis on breed differences. Other aims were to study differences between primiparous and older cows in the distribution of bacterial findings at clinical mastitis, and the occurrence of VTCM and bacterial findings in relation to stage of lactation using data from a Swedish field study performed 2002-2003. Descriptive statistics and univariable analyses were used in the investigations. During 2002-2006 approximately 10% of Swedish primiparous cows experienced VTCM each year, while the geometric mean SCC of Swedish primiparous cows was approximately 65,000 ml(-1). Both parameters were lower than in older cows. Primiparous cows of the Swedish Red (SR) breed had better udder health than cows of the Swedish Holstein (SH) breed. The overall distribution of udder pathogens was similar in primiparous and older cows. In primiparous cows, most VTCM occurred during the first week after calving, and Staphylococcus aureus and Streptococcus dysgalactiae were the most common udder pathogens during this period. Better control measures directed at these infections are warranted around calving to reduce the risk of mastitis in primiparous cows.

Antimicrobial susceptibility of udder pathogens from cases of acute clinical mastitis in dairy cows.

To investigate occurrence of acquired antimicrobial resistance in udder pathogens MICs in Staphylococcus aureus (n=211), coagulase-negative staphylococci (CNS) (n=56), Streptococcus uberis (n=113), Streptococcus dysgalactiae (n=152), Streptococcus agalactiae (n=6), Escherichia coli (n=163), and Klebsiella spp. (n=42) were determined using microdilution. Isolates were from a nation wide survey employing strict inclusion criteria. Presence of acquired resistance was evaluated by species-specific epidemiological cut-off values issued by EUCAST. Penicillin or methicillin resistance in staphylococci were however evaluated by beta-lactamase production or presence of the mecA gene, respectively. Staphylococci were mostly susceptible to antimicrobials tested but 7.1% of S. aureus and 12.5% of CNS were resistant to penicillin by beta-lactamase production. Methicillin resistance was not found in S. aureus. All Streptococcus dysgalactiae and S. agalactiae were susceptible to penicillin. Bimodal MIC distributions for tetracycline in S dysgalactiae and S. uberis indicate acquired resistance in some isolates. Among E. coli 12.3% of isolates were resistant to one or more antimicrobials. Resistance to streptomycin (11.0%), sulphametoxazole (8.6%), ampicillin (7.4%), or tetracycline (4.9%) were the most common traits. Klebsiella spp. were resistant to ampicillin and some isolates also to tetracycline (7.1%) or sulphonamide (9.5%). The study shows that in Sweden bacteria associated with acute clinical mastitis for the most part are susceptible to antimicrobials used in therapy but resistance to penicillin in S. aureus is not uncommon. Penicillin is recommended for treatment of mastitis caused by gram-positive pathogens and regular monitoring of beta-lactamase production in S. aureus is therefore recommended in herds with udder health problems.

The rise and fall of a vancomycin-resistant clone of Enterococcus faecium among broilers in Sweden.

OBJECTIVES: Historically, vancomycin-resistant enterococci (VRE) have been very common among farm animals in Europe, and they can still be readily isolated using media supplemented with vancomycin. An increase in the occurrence of VRE among broilers in Sweden was reported during 2000-2005. This was due to the spread of one clone of VRE in the apparent absence of selective pressure. The aims of this study were to estimate the current occurrence of VRE among Swedish broilers and to investigate if there had been any changes with regards to the dominating clone and antimicrobial resistance pattern. METHODS: Caecal samples (n=100) collected at slaughter from healthy broilers were cultured on Slanetz-Bartley agar supplemented with vancomycin (16 mg/L). Presumptive VRE were identified to species using MALDI-TOF MS, susceptibility tested using broth micro-dilution, and whole genome sequenced to investigate the genetic relationship with previous isolates. RESULTS: Eleven (11%) of the samples were positive for VRE. This was a statistically significant decrease in the proportion of positive samples from 2010. The same clone as before still prevailed. CONCLUSIONS: The occurrence of VRE among broilers in Sweden has decreased. However, just as the occurrence of VRE among Swedish broilers increased in the apparent absence of selective pressure, the reasons for the decrease is unknown.

Suspected transmission and subsequent spread of MRSA from farmer to dairy cows.

In the present study we describe an outbreak where PVL positive MRSA belonging to spa-type t002 and multi-locus sequence type ST2659 persisted in a Swedish dairy herd for at least two years, despite efforts to hinder transmission between animals and between the farmer and his animals. This is the first description of persistence and spread of MRSA in a dairy herd in Sweden. Sampling of animals in the herd was initiated by the finding of MRSA in the farmer and was performed at eight occasions from November 2012 to September 2014. In total, MRSA was detected in 25 animals and in 16 of these MRSA was detected in milk samples. In addition, MRSA was also detected in bulk milk samples. Whole genome sequencing (WGS) of twelve isolates from farmer (n = 1), animals (n = 9) and bulk milk (n = 2) revealed high relatedness, implying a common source. MRSA may initially have been transmitted from humans to cows with further spread within the herd. WGS showed minor differences in one isolate (loss of phage ΦN315) which could indicate adaption of the strain to an animal host.

Clonal spread of Escherichia coli resistant to cephalosporins and quinolones in the Nordic broiler production.

The intestinal flora of healthy broilers can contain Escherichia coli resistant to extended spectrum cephalosporins (ESC) and fluoroquinolones (FQ), representing a possible public health problem. We investigated the clonal epidemiology of E. coli with reduced susceptibility to ESC or FQ in broilers in three Nordic countries interconnected by a common source of breeding animals. Isolates (n = 319 and n = 132 non-wild type for ESC and FQ, respectively) from Norwegian, Swedish and Icelandic production originated mainly from the intestinal flora of broilers at the age of 20-35 days. Genetic relationships were investigated by ten loci multilocus variable number tandem repeat analyses (MLVA) and representative isolates of inter-Nordic clusters were subjected to multilocus sequence typing (MLST). Antimicrobial susceptibility data based on minimum inhibitory concentrations was compiled. Approximately one third of the ESC non-wild type isolates, including isolates from all three countries, clustered together. These isolates belonged to sequence type (ST) 38 and contained blaCMY-2. The FQ non-wild type isolates were more genetically diverse, but related isolates occurred in more than one country. MLST typing showed clusters belonging to ST10, ST355, ST349, ST665 and ST93. Our study demonstrated inter-Nordic distribution of E. coli ST38 with blaCMY-2, suggesting clonal proliferation as a contributing factor for spread of ESC resistance in the broiler production. The international trade in breeding material may explain introduction of resistant E. coli. The reason for their success and the success of certain clonal lineages in broiler production not exposed to antimicrobial selection pressure is currently unknown.

Methicillin-resistant Staphylococcus aureus not detected in Swedish nucleus and multiplying pig herds.

Introduction: Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) has emerged among pigs in many countries. MRSA in the pig population constitute a reservoir with risk for transmission to humans in close contact with pigs. Absence of MRSA in the top of the breeding pyramid would prevent spread to the rest of the pig population. The aim of this study was to investigate the occurrence of MRSA in nucleus and multiplying pig herds in Sweden. Materials and methods: All nucleus and multiplying pig herds in Sweden present in 2011 (n = 53) and 2014 (n = 39) were sampled for MRSA. Results and discussion: MRSA was not detected either in 2011 or in 2014. That MRSA was not detected in the top of the breeding pyramid indicates a favourable MRSA situation in the Swedish pig population. Abbreviations: MRSA: methicillin-resistant Staphylococcus aureus; LA-MRSA: livestock-associated MRSA; CC: clonal complex.

High occurrence of mecC-MRSA in wild hedgehogs (Erinaceus europaeus) in Sweden.

We investigated the occurrence of mecC-MRSA in wild hedgehogs (Erinaceus europaeus) in Sweden and characterized the obtained isolates. Samples from 55 hedgehogs from five counties of Sweden were cultivated selectively for MRSA and putative isolates were confirmed by real-time PCR detecting mecA, mecC, nuc and PVL genes. mecC-MRSA was confirmed in 35 (64%) animals from three geographically separated counties. Confirmed isolates were spa-typed and tested for antimicrobial susceptibility by broth microdilution. Eight different spa-types were identified (t843, t978, t3391, t9111, t10751, t10893, t11015, t15312) of which t843 (49%) was the most common. The spa-types t843, t3391 and t978 were found in isolates from two counties. The study shows that mecC-MRSA is common in wild hedgehogs in two counties of Sweden but occurs in hedgehogs also in other parts of the country. Our findings suggest that hedgehogs could be a reservoir for mecC-MRSA. In addition, similar spa-types of isolates from hedgehogs and isolates previously described in domesticated animals and in humans indicates transfer between these populations.

Campylobacter coli in Organic and Conventional Pig Production in France and Sweden: Prevalence and Antimicrobial Resistance.

The purpose of the study was to evaluate and compare the prevalence and antimicrobial resistance of Campylobacter coli in conventional and organic pigs from France and Sweden. Fecal or colon samples were collected at farms or at slaughterhouses and cultured for Campylobacter. The minimum inhibitory concentrations of ciprofloxacin, nalidixic acid, streptomycin, tetracycline, erythromycin, and gentamicin were determined by microdilution for a total of 263 French strains from 114 pigs from 50 different farms and 82 Swedish strains from 144 pigs from 54 different farms. Erythromycin resistant isolates were examined for presence of the emerging rRNA methylase erm(B) gene. The study showed that within the colon samples obtained in each country there was no significant difference in prevalence of Campylobacter between pigs in organic and conventional productions [France: conventional: 43/58 (74%); organic: 43/56 (77%) and Sweden: conventional: 24/36 (67%); organic: 20/36 (56%)]. In France, but not in Sweden, significant differences of percentages of resistant isolates were associated with production type (tetracycline, erythromycin) and the number of resistances was significantly higher for isolates from conventional pigs. In Sweden, the number of resistances of fecal isolates was significantly higher compared to colon isolates. The erm(B) gene was not detected in the 87 erythromycin resistant strains tested.

Risk for the development of Antimicrobial Resistance (AMR) due to feeding of calves with milk containing residues of antibiotics.

EFSA was requested to: 1) assess the risk for the development of antimicrobial resistance (AMR) due to feeding on farm of calves with colostrum potentially containing residues of antibiotics; 2) assess the risk for the development of AMR due to feeding on farm of calves with milk of cows treated during lactation with an antibiotic and milked during the withdrawal period, and 3) propose possible options to mitigate the risk for the development of AMR derived from such practices. Treatment of dairy cows during the dry period and during lactation is common in the EU Member States. Penicillins, alone or in combination with aminoglycosides, and cephalosporins are most commonly used. Residue levels of antimicrobials decrease with the length of the dry period. When the interval from the start of the drying-off treatment until calving is as long as or longer than the minimum specified in the Summary of Product Characteristics of the antimicrobial, faecal shedding of antimicrobial-resistant bacteria will not increase when calves are fed colostrum from treated cows. Milk from cows receiving antimicrobial treatment during lactation contains substantial residues during the treatment and withdrawal period. Consumption of such milk will lead to increased faecal shedding of antimicrobial-resistant bacteria by calves. A range of possible options exist for restricting the feeding of such milk to calves, which could be targeting the highest priority critically important antimicrobials. ß-Lactamases can reduce the concentration of ß-lactams which are the most frequently used antimicrobials in milking cows. Options to mitigate the presence of resistant bacteria in raw milk or colostrum are mainly based on thermal inactivation.