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Research article2023Peer reviewedOpen access

Molecular Characterization of Methicillin-Resistant Staphylococci from the Dairy Value Chain in Two Indian States

Dey, Tushar K.; Shome, Bibek R.; Bandyopadhyay, Samiran; Goyal, Naresh Kumar; Lundkvist, Ake; Deka, Ram P.; Shome, Rajeswari; Venugopal, Nimita; Grace, Delia; Sharma, Garima; Rahman, Habibar; Lindahl, Johanna F.


Bovine milk and milk products may contain pathogens, antimicrobial resistant bacteria, and antibiotic residues that could harm consumers. We analyzed 282 gram-positive isolates from milk samples from dairy farmers and vendors in Haryana and Assam, India, to assess the prevalence of methicillin-resistant staphylococci using microbiological tests, antibiotic susceptibility testing, and genotyping by PCR. The prevalence of genotypic methicillin resistance in isolates from raw milk samples was 5% [95% confidence interval, CI (3-8)], with 7% [CI (3-10)] in Haryana, in contrast to 2% [CI (0.2-6)] in Assam. The prevalence was the same in isolates from milk samples collected from farmers [5% (n = 6), CI (2-11)] and vendors [5% (n = 7), CI (2-10)]. Methicillin resistance was also observed in 15% of the isolates from pasteurized milk [(n = 3), CI (3-38)]. Two staphylococci harboring a novel mecC gene were identified for the first time in Indian dairy products. The only SCCmec type identified was Type V. The staphylococci with the mecA (n = 11) gene in raw milk were commonly resistant to oxacillin [92%, CI (59-100)] and cefoxitin [74%, CI (39-94)], while the isolates with mecC (n = 2) were resistant to oxacillin (100%) only. All the staphylococci with the mecA (n = 3) gene in pasteurized milk were resistant to both oxacillin and cefoxitin. Our results provided evidence that methicillin-resistant staphylococci occur in dairy products in India with potential public health implications. The state with more intensive dairy systems (Haryana) had higher levels of methicillin-resistant bacteria in milk.


Methicillin resistance; MRSA; MRCoNS; dairy; milk; food safety; farmers; vendors

Published in

2023, Volume: 12, number: 2, article number: 344

    Associated SLU-program

    AMR: Bacteria

    UKÄ Subject classification

    Animal and Dairy Science
    Food Science

    Publication identifier


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