Occurence and antimicrobial resistance of common udder pathogens isolated from sheep milk in Slovakia

Abstract

The aim of this work is to identify the spectrum, frequency and antimicrobial resistance of bacterial pathogens occurring in sheep dairy herds in Slovakia. Of a total of 310 samples of sheep's milk coming from three breeds during two seasons (2017 and 2018), at least one potential pathogen was isolated from 102 samples (32.9%). A total of 131 microbial isolates were isolated. The most represented species were coagulase negative staphylococci CoNS (75.6%), followed by Streptococcus agalactiae (10.7%), Staphylococcus aureus (6.9%), Streptococcus dysgalactiae (4.6%), Escherichia coli (1.5%), Enterococcus faecium (1.5%), and others (Streptococcus uberis, Streptococcus parauberis, Candida sp., Klebsiella sp., moulds) below 1%. A total of 99 isolates of CoNS were tested for antimicrobial resistance. Of these, 63.6% were resistant to at least one antibiotic. A total of 24.2% of the tested isolates were resistant to 3 groups of antimicrobials simultaneously (multi-drug resistance). The highest resistance was observed to lincomycin (57.6%) and neomycin (36.4%), the lowest to sulfamethoxazolum+trimethoprim (0%) and enrofloxacin (3.0%). Based on the results of this work, it is possible to assume a similar spectrum of pathogens and their antimicrobial resistance described in the literature also within the Slovak sheep farms focused on milk production.