Exploring prevalence, antimicrobial susceptibility, virulence profiles, and multidrug resistance in Staphylococcus aureus isolates from respiratory disease-affected sheep and goats in migratory communities of Lower Himalayas

Staphylococcus aureus is a significant bacterium that causes substantial economic losses in the livestock sector and poses life-threatening risks to both humans and animals. This study aimed to explore the prevalence, susceptibility to antimicrobials, and profiles of virulence and antimicrobial resistance (AMR) genes in S. aureus isolated from nasal swabs and lung tissues of sheep and goats exhibiting symptoms of respiratory disease. A total of 194 samples were examined, resulting in the isolation and confirmation of S. aureus in 65 samples, indicating an overall prevalence of 33.5%. These isolates were further subjected to an AMR assay. Among the representative isolates (37), sensitivity was observed to chloramphenicol and ceftriaxone. Conversely, penicillin showed the lowest efficacy, with 83.8% of isolates demonstrating resistance, followed closely by amoxiclav, which exhibited resistance in 75.7% of isolates. Close to threequarters of isolates carried at least one AMR gene. Virulence genes were identified in 67.6% of S. aureus isolates, with coa and lukpv detected in 37.8% and arcA in 32.4% of isolates. Additionally, mecA and vatC were present in 54.05%, vatB in 43.25% and aphD in 18.91% of S. aureus isolates. A substantial 91.9% of isolates exhibited multidrug resistance, and MAR indices exceeding 0.2 were recorded in 86.5% of S. aureus isolates, indicating a high public health risk. These findings underscore the importance of prioritizing infections caused by S. aureus, necessitating heightened attention from both veterinarians and healthcare workers in migratory communities. Furthermore, the regulated and judicious use of antimicrobials is crucial to mitigate the risks associated with antimicrobial resistance in these settings.