Vol. 10, Special Issue 11 (2021)

Author(s):
Jasleen Kaur, Pawanjit Singh Cheema, Naresh Kakkar, Jeenu Manoj and Rajesh Chhabra

Abstract:
Methicillin resistant Staphylococcus aureus (MRSA) a common ‘superbug’ poses a clinical threat in human beings as well as animals and is a serious pathogen leading to variety of infections. The present study was conducted to determine the occurrence of MRSA in milk of mastitis buffaloes. A total of 232 quarter milk samples received in College Central Laboratory for routine examination were processed for identification and isolation of Staphlococcus aureus. Preliminary identification of Staphylococcus aureus was done on the basis of growth characteristics on blood agar and mannitol salt agar, catalase test, oxidase test and HiStaph latex agglutination kit. One hundred and two isolates were identified as Staphylococcus aureus with yellowish discoloration around the colonies in manitol salt agar and typical small yellow colonies on blood agar. For detection of MRSA, growth on MeReSa agar and PCR assay targeting mecA gene was used. On the basis of growth on MeReSa agar, 11 (10.78%) isolates were identified as MRSA showing bluish green colonies whereas PCR assay revealed 33 (32.35%) were found to possess the mecA gene with 162 bp product size. The presence of such a large proportion of MRSA in milk from mastitis animal is a significant challenge for food industry and dairy industry.