Abstract:
Staphylococcus aureus is recognized worldwide as one of the major agents of dairy cow intra-mammary infections and
cause a wide variety of clinical diseases in humans. Staphylococcus aureus can be transferred during milking from milkers
(especially from their hands that come into contact with the udder) to cows. The exchange of resistance genes is very
effective during colonization or infection of host organisms. The aim of this study was to determine the prevalence of
Staphylococcus aureus isolated from the nasal cavities of milkers. In this study were taken 30 samples from nostrils of
milkers and 66.6% of them were confirmed as Staphylococcus aureus. For these isolates, 25 antibiotics were tested using
the PBC29 panel and all isolates (100%) were found to be resistant to ampicillin and penicillin. Through the qPCR
reaction, 6 resistance genes (blaZ, cfr, ermB, ermC, mecA, and tetK) were tested and 13 antibiotics were associated with
them. For each gene it was calculated the penetrance (P%) and diagnostic odds ratio (DOR) to see if the phenotypic
expression of resistance/susceptibility is also found in genes. In this study, overall penetrance was P%=52%, the
penetrance had values between 22% (tetK) and 80% (blaZ) and DOR had superunitary values in mecA gene (DOR=1.21),
cfr (DOR=1.53), ermB (DOR=2.54) and ermC (DOR= 5.44).This approach can enhance the understanding of plasmidborne
resistance and improve diagnostic accuracy, ultimately contributing to better management of antimicrobial
resistance in veterinary settings.
