Identification, Superantigen Toxin Gene Profile and Antimicrobial Resistance of Staphylococci Isolated from Polish Primitive Sheep Breeds

SIMPLE SUMMARY: Current knowledge regarding the occurrence, differentiation, and pathogenicity of staphylococci isolated from animals is mainly based on clinical isolates, but little is known about staphylococci colonizing healthy animals. Even less is known about staphylococci that colonize sheep. While considering the microbiota inhabiting the primitive native breeds of sheep from the ecological/agritourism farm, there is no such information at all. The current study aimed to identify staphylococcal species isolated from healthy sheep of two native breeds (Świniarka and Wrzosówka) kept on the same ecological/agritourism farm. Furthermore, the prevalence of selected toxin genes and antimicrobial resistance was also determined. A total of 127 coagulase-negative staphylococci were identified from 61 sheep (33 of Świniarka) and (28 of Wrzosówka). From 1 to 4 staphylococcal isolates were obtained from one sheep. Staphylococcus aureus was not identified in any of the samples. In total, seven different species were identified. Over 60% of staphylococci were resistant to at least one antimicrobial of therapeutic importance and over 77% possessed from 1 to 7 genes encoding different toxins. The findings of this study prove that toxigenic and antimicrobial-resistant coagulase-negative staphylococci can colonize the nasal cavity of healthy sheep of primitive, native breeds. ABSTRACT: The study aimed to analyze staphylococcal microbiota of the nasal cavity of the primitive sheep breeds Polish Świniarka and Wrzosówka kept on the same ecological farm. The research included the identification of staphylococcal species, evaluation of the prevalence of genes encoding enterotoxins, staphylococcal enterotoxin-like proteins, exfoliative toxins, toxic shock syndrome toxin 1, and detection of antimicrobial resistance. From 61 swab samples gathered from Świniarka (33) and Wrzosówka (28) healthy sheep, 127 coagulase-negative staphylococci (CoNS) were isolated. Based on PCR-RFLP analysis of the gap gene using AluI and HpyCH4V enzymes, the isolates were identified as: Staphylococcus xylosus (33.9%), S. equorum (29.1%), S. arlettae (15%), S. warneri (9.4%), S. lentus (7.9%), S. succinus (3.9%) and S. sciuri (0.8%). Three of these species, S. lentus, S. succinus, and S. sciuri, were detected only from the Świniarka breed. It was found that 77.2% of isolates harbored from 1 to 7 out of 21 analyzed genes for superantigenic toxins. The greatest diversity of toxin genes was recorded for S. equorum (16 different genes). The most prevalent gene was ser (40.2%). The incidence and number of resistances to antimicrobials were found to be bacterial species but not sheep breed dependent. The highest percentage of resistance was found for S. sciuri. The most frequent resistance was observed to clindamycin (45.7%). The findings of this study prove that toxigenic and antimicrobial resistant CoNS can colonize the nasal cavity of healthy sheep.