Salmonellosis is a public health concern worldwide and also causes huge losses to the piggery industry. A total of 457 fecal samples were collected from organized and unorganized farms including indigenous and crossbreed piglets of North East India. Salmonella isolates were serotyped, screened for their virulence genes, characterized for drug resistance pattern and representative isolates were cloned and sequenced for their partial length enterotoxin (stn) gene. A total of 8.31% Salmonella were identified with higher prevalence observed in unorganized compared to organized farms and higher detection level in cross breed compared to indigenous piglets. Salmonella typhimurium (65.78%) was found to be the predominant serovar and irrespective of serovars high number of isolates (68.4%) harboured enterotoxin gene. The isolates were multidrug resistant showing highest resistance against cefalexin (77.31%). Sequence analysis of stn gene showed two isolates having diverse sequence compared to other isolates. Our study revealed the significance of Salmonella as important pathogen with zoonotic potential between porcine and human populations. This is probably the first systematic study of Salmonella species associated with piglet diarrhea in India.
The objectives of this study were to determine the genetic relatedness, antibiogram and virulence factors of Staphylococcus aureus (S. aureus) isolated from bovine mastitis, associated farm workers, dairy cow farm veterinarians (private veterinarians), veterinary students, and non-veterinary university students. A total of 84 S. aureus isolates (27 from mastitis, 11 from farm workers, 9 from private veterinarians, 22 from veterinary students, and 16 from non-veterinary university students) were used to determine antimicrobial sensitivity patterns using disk diffusion test, virulence factors using PCR technique and phylogenic analysis using pulsed field gel electrophoresis. All S. aureus isolates were resistant to 2 or more commonly used antibiotics. All isolates from mastitis, farm workers, and veterinary students carried the genes encoding coagulase and thermonuclease factors while isolates from non-veterinary university students carried the genes encoding coagulase, clumping, and thermonuclease factors. The mecA gene was detected in 22.2%, 81.8%, 100%, 95.5% and 100% of isolates from mastitis, farm workers, private veterinarians, veterinary students, and non-veterinary university students, respectively. In the phylogenic analysis, 10 (45.5%), 6 (66.7%) and 8 (72.7%) isolates from veterinary students, private veterinarians and farm workers, respectively were more than 80% similar to isolates from mastitis. Results of this study indicate that S. aureus isolates from mastitis milk and those from related dairy cow personnel and veterinarians share similar antimicrobial sensitivity patterns and virulence factors, therefore a common source of bacteria may exist. Furthermore, possible transmission of S. aureus between cows and cow-related personnel and vice versa could also exist.