Prevalence Study of Antimicrobial Resistance among Invasive Salmonella spp. in Milk and Dairy Products in India

Background: Food safety has emerged as an important global issue with expanded international trade and various public health implications. Milk and dairy products are rich in many nutrients hence offer favourable environments for the growth of various food borne pathogens. Of which in past decades Salmonellosis is a frequently reported zoonotic foodborne disease in world. Although India is a leading contributor of World’s milk production along with increased consumption of milk and dairy products, only a few information is available on the prevalence status of Salmonella spp. in milk and dairy products. Hence the study was aimed to study the prevalence of Salmonella spp. and its antimicrobial resistance pattern by phenotypic methods that has been recovered from different study samples. Methods: Polymerase Chain Reaction (PCR) was adopted to confirm the Salmonella spp. and then phenotypically the antimicrobial resistance pattern was studied by Kirby Bauer disc diffusion method. Result: A total of 567 samples (75 Raw milk samples, 45 pasteurized milk samples and 447 dairy products) were screened and four Salmonella isolates which was derived from the dairy products were confirmed by PCR targeted the invA gene that encodes the invasion protein of Salmonella. The isolates showed multiple drug resistance and also has higher MAR indices along with 75 % resistance to the antibiotics viz, Cephalothin, Penicillin and Enrofloxacin. The presence of Salmonella spp. in milk and dairy products and their AMR to common antibiotics in the study area indicates that emerging resistance pattern of food borne Salmonella spp. and possibility of entering the food chain which is of high risk to the consumers.