Mastitis pathogens and somatic cell count in ewes milk

The aim of this study was to determine the occurrence of pathogens in selected group of ewes and the relationship between somatic cell count (SCC) and the presence of pathogens. The experiment was carried out on a dairy farm, where predominantly breed was a Tsigai. Sampling was carried out in monthly intervals as part of the milk recording test day from February to July 2019. A total of 303 ewes were included in the survey, during the milk recording test day. The ewes with SCC ≥1000 × 103 cells.mL-1 were selected for further sampling at half udder level. Based on SCC the ewes were divided into five groups: <200 ×103; ≥200 <400 × 103; ≥400 <600 × 103; ≥600 <1000 × 103; ≥1000 × 103 cells.mL-1. The first group of SCC contained 33.9% of milk samples, the second 14.1% of samples, the third 5.7% of samples, the fourth 6.2% and the fifth 40.1% of samples. The most common pathogens were coagulase negative staphylococci (CNS). The most frequent CNS was Staphylococcus (S.) simulans (24.4%). S. aureus was identified in 5.3% of bacteriological positive samples. Almost 70% of ewes with bacteriological positive samples were repeated identified the presence of pathogens during tested period. SCC ≥500 × 103 cells.mL-1  were detected in 92.5% bacteriological positive milk samples. The presence of pathogens increased SCC in milk (p <0.001) as compared to samples free of pathogens. In conclusion, the SCC ≥500 × 103 cells.mL-1 could be important for detection of subclinical mastitis at half udder level in dairy ewes.

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

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.