SvarmPat – focus on antimicrobial resistance in animal pathogens
In 2005, increased surveillance of antimicrobial resistance in bacteria causing disease in pigs, cattle, sheep or poultry was initiated through the programme -SvarmPat. The programme is run in collaboration between the Swedish National Veterinary Institute (SVA) and Farm and Animal Health and is financed by the Swedish Board of Agriculture.
Resistance data for animal pathogens have been reported and evaluated annually in Svarm since 2000 (Svarm-reports). Data presented have mostly been compilations of results from the routine diagnostic activities at SVA but results from specific research projects in this field have also been presented. Monitoring based on diagnostic submission is to some extent unsatisfactory since a large proportion of the isolates are likely to be from herds with disease problems where antimicrobial use is common. Thereby the material is biased and most likely reflects a “worst case” scenario not relevant for the situation in most herds. In addition, anamnestic information accompanying routine diagnostic submissions is often scarce and non-systematic, thus duplicate samples from the same animal or herd can be included in the compiled data. Lack of anamnestic information also curbs the possibilities to use the data for inference in an epidemiological context. Lastly, relying on routine submissions implies that for some pathogens, very few isolates are tested for antimicrobial susceptibility. Consequently, due to a small sample size data for these pathogens are unsuited for further conclusions on occurrence of resistance and possible trends in resistance.
The objective of SvarmPatis to improve the monitoring of pathogens in farm animals by collecting high-quality unbiased data on antimicrobial resistance for an appropriate number of isolates. Results are reported yearly in the Svarm report and are communicated in other ways as well. Updated knowledge on susceptibility of animal pathogens is thereby available for practitioners, facilitating the therapeutic choice in the clinical setting. Moreover, high-quality data allows appropriate analysis of trends in resistance and of underlying causes for such trends.
Pathogens, like Escherichia coli in cattle and pigs are of highest priority in SvarmPat, together with Brachyspira spp. from pigs and Pasteurella spp. and Mannheimia spp. from cattle, pigs and sheep. Udder pathogens are also of main concern in the programme. One activity in SvarmPat are to encourage practitioners and pathologist to submit samples for microbiological culture and susceptibility testing. This applies specifically to Pasteurella spp. and Mannheimia spp. from cattle where currently few isolates are tested yearly but also Staphylococcus hyicus and Actinobacillus pleuropneumoniae from pigs. Studies that address the correlation between virulence factors (toxin production and adhesion factors) to resistance phenotype in E. coli in pigs is of interest. Such knowledge could help practitioners to initiate treatment only when ”true” pathogens are present, i.e. E. coli that produce both toxin and have adhesions factors.
By long term monitoring, SvarmPat will lead to increased and in-depth knowledge of antimicrobial resistance in pathogens from Swedish farm animals. This will be a keystone for prudent use of antimicrobials, which, in a wider perspective, curbs the emergence and spread of antimicrobial resistance. Thereby, effective antimicrobial therapy of farm animals, imperative for a good animal health status, is ensured in the future.