Prevalence of blaZ gene and antibiotics susceptibility test profile of β-lactams resistant Staphylococcus aureus isolated from subclinical mastitis in lactating Beetal goats

Abstract

Staphylococcus aureus is one the most significant causative pathogens of subclinical mastitis in lactating Beetal goats. This study was designed to determine the prevalence of subclinical mastitis caused by Staphylococcus aureus, their susceptibility to different antibiotics, and detection of blaZ gene prevalence in β-lactams resistant Staphylococcus aureus isolates via polymerase chain reaction. A total of 450 lactating Beetal goats revealed that 92 (20.45%) were positive while 358 (79.55%) were negative for subclinical mastitis. Further, 331 Staphylococcus species were isolated from 450 subclinically mastitic teats with a prevalence of 73.55%. Staphylococcus aureus were the most prevalent, as 34 (10.28%) pure Staphylococcus aureus isolates while 297 (89.72%) isolates mixed with other various bacteria were isolated. Results of antibiotics susceptibility test profile against Staphylococcus aureus isolated from subclinically mastitic milk showed high resistances against streptomycin and floramphenicol while a moderate resistance was recorded against ampicillin. Furthermore; polymerase chain reaction was applied on 10 β-lactam resistant Staphylococcus aureus pure isolates for blaZ gene detection. This gene was detected in 60% of pure Staphylococcus aureus isolates. To best of my knowledge, this is the initial report concerning the molecular detection of blaZ gene isolated from subclinically mastitic milk of lactating Beetal goats in Pakistan. It will aid to provide information for developing the control and prevention strategies against subclinical mastitis caused by Staphylococcus aureus in lactating Beetal goats.