Detection of mecA gene-associated methicillin-resistance coagulase-negative staphylococci (MRCoNS) from bovine mastitis in Gujarat

Abstract

Exploration of pathogenic potential of Coagulase-Negative Staphylococci (CoNS), in human as well as animals, gained the importance during the past two decades. Emergence of Methicillin-Resistant Coagulase-Negative Staphylococci (MRCoNS) in bovine milk poses to be a major public health concern. Presence of the mecA gene is one of the most common reasons reported for the methicillin resistant bacteria. Since the scientific data concerning the presence of mecA gene and MRCoNS in bovine milk is very limited in India, particularly from Gujarat state, the present study was planned to detect mecA gene in 25 MRCoNS and study the antibiogram of 33 CoNS isolated from 185 bovine mastitis cases between January 2018 to December 2019. Staphylococci were isolated from the milk samples of bovine mastitis with a prevalence of 38.9% (72/185), out of which 39 (54.16%) and 33 (45.83%) isolates were identified as coagulase-positive Staphylococci (CoPS) and coagulase-negative Staphylococci (CoNS), respectively. Among the CoNS, S. xylosus was the most predominantly isolated species (9/33, 27.27%), followed by S. epidermis (6/33, 18.18%) and S. haemolyticus (4/33, 12.12%). Out of these 33 isolated CoNS, 21 (63.63%) and 25 (75.75%) were identified as MRCoNS by disc diffusion method and CHROM agar, respectively. Contrary to the likelihood, only 3 MRCoNS showed the presence of mecA gene using PCR method. Antibiogram revealed that most of the CoNS isolates (84.85%) were multi-drug resistant emphasizing the urgent need of restricting the indiscriminate use of antimicrobial drugs in the area of study.