Isolation and Antimicrobial Drug Susceptibility Profiling of Salmonella isolates from Raw Milk

Abstract

]The present study was conducted to determine the prevalence of Salmonella spp. in milk. The samples were collected from two intermediaries viz. farms (n=50) and retail shops (n=50) and antimicrobial susceptibility of the isolates were performed. The overall prevalence of Salmonella isolates at dairy farm was recorded as 28% amongst which 50% were S. typhi. Further, results revealed that eight dairy farms (80%) were positive, while two farms (20%) were detected as negative for Salmonella. The maximum prevalence was noted in Farm 7 (100%) whereas; milk samples from Farm 2 and Farm 10 were free from Salmonella contamination .None of the dairy shops found free of Salmonella carriage. The overall prevalence of salmonella was recorded as 44%. Among the salmonella isolates the prevalence of S.typhi was 54%. The maximum prevalence (60%) of Salmonella spp. in milk was noted in samples from five shops i.e. Shop 2, 4, 5, 9 and 10. More so, S. typhi was detected in 70% of milk samples from all seven shops except Shop 3, 6 and 9 which showed maximum carriage as 100%. Whereas, samples from three shops viz. Shop 1, 2 and 7 were free of S. typhi contamination. The organisms were found highly resistant to Neomycin and Kanamycin (84.21%) followed by Oxytetracycline (78.95%), Tetracycline (73.68%), Gentamycin (68.42%), Cefixime (52.63%), Cefoxitin (47.37%), Ciprofloxacin (36.84%) and Cefipime (32.11%). The overall MDR profile showed 68.4% S. typhi isolates were resistance to three and/or above antibiotics. A total of 26.31%, 21.04%, 15.78 and 5.26%, S.typhi showed resistance against three, four, five and six antimicrobial agents, respectively.