Prevalence and molecular characterization of Salmonella species associated with piglet diarrhea in North East India.

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.