Prevalence and antibiogram profiling of enterotoxigenic methicillin-resistant Staphylococcus aureus at bovine-human interface.

Background: Staphylococcus aureus, a ubiquitous pathogen due to its key involvement in dairy animal mastitis, is the leading cause of food-borne diseases in humans by producing various enterotoxins. Aims: The present study reported the prevalence of significantly increased enterotoxigenic MRSA pathogens among bovines and dairy occupational workers, along with antibiotic-resistant patterns, using the in-vitro technique.

Methods: A total of 384 bovine (n=192 cattle, n=192 buffalo) milk samples and 100 human nasal or skin swab samples were collected to find out the prevalence of S. aureus, MRSA, spa, and enterotoxin genes (seb, sec) by PCR. Also, a phylogenetic analysis was conducted to compare and analyze the prevalent enterotoxin seb gene sequences from bovines, workers, and other sources.

Results: The present study revealed that out of 484 total samples, 49.79% of isolates were positive for S. aureus while 29.46% and 66.80% of S. aureus isolates were positive for MRSA, and spa genes among bovine and human samples collectively. The prevalence of enterotoxigenic S. aureus was found to be 16.18% in bovine and human staphylococcal isolates. Additionally, the enterotoxigenic strains exhibited resistance to commonly used antibiotics.

Conclusion: The present study shows that enterotoxigenic MRSA is prevalent in bovines and dairy occupational workers of study districts, Pakistan, and study isolates revealed a varying level of resistance to different antibiotics. The various virulence factors along with the antibiotic resistance makes MRSA a potential threat at animal-human interface, highlighting the need for further research.