Identification of Antimicrobial – Resistant Genes in S. aureus Isolated from Subclinical Mastitis Infected Ewes

Mastitis, which is defined as inflammation of the mammary gland, typically causes changes to the udder's anatomy and physiology. The aim of this research was to identification of antibiotic-resistant Staphylococcus aureus isolated from sheep with subclinical mastitis by molecular detection. Staphylococcus aureus isolates were molecularly detected using 16 Sr RNA and resistance virulence genes (mecA, ermA, ermB, and blaZ) using the traditional PCR method. The results were also validated using VITEK 2 systems. Two hundred samples were collected from the subclinical mastitis of infected ewes from different areas in Babylon Province. Samples were preserved on an icebox and transported to the laboratories. Milk samples were cultured on Blood and Mannitol Salt Agar (7.5%) plates. The culture plates were then incubated at 37°C for 24 hours. The results of milk samples cultured on different media revealed the following: Green, motile colonies of S. aureus are produced on selective Hi Chrome agar. The current study found that the percentage of infected halves was 19–29 half infected and 5–29 two halves infected, and that the prevalence of subclinical mastitis was 24 (45.83%) based on the CMT and bacterial isolation. The 16S rRNA gene was amplified in all 20 isolates, according to the PCR assay, and the mecA, ermA, ermB, and blaZ genes were amplified in all 20 isolates. Every S. aureus isolate that tested positive came from mastitis-infected sheep. Twenty antimicrobial agents were used in the antibiotic susceptibility tests for S. aureus isolates. In summary, the findings indicate that S. aureus has become highly resistant to antibiotics.