Molecular characterization of Salmonella serovars of zoonotic importance

Abstract

Isolates (50) of Salmonella were recovered from 1,132 samples from foods of animal origin and fecal samples from animals and human beings; belonging to 10 different serovars with most prevalent serovar S. Typhimurium (21) followed by S. Weltevreden (12), S. Ughelli (5), S. Essen (3), S. Elisabethville (2), S. Lagos (2), S. Drogana (2), S. Enteritidis (1), S. London (1) and un-typable Salmonella (1). Emerging Salmonella serovars, viz S. Elisabethville, S. Essen, S. Lagos, S. Ughelli and S. Drogana were first time recovered from Pantnagar and its vicinity. S. Drogana was recovered possibly for the first time from human source in India. Multiple Salmonella serovars (up to 3 serovars comprising S. Typhimurium, S. Weltevreden and S. Essen) were recovered from single cattle dung sample while, multiple serovars (up to 2 serovars) were also recorded in many single samples, viz cattle dung (S. Weltevreden and S. Ughelli), poultry droppings (S. Essen and S. Ughelli), pig faeces (S. Weltevreden and S. London), sheep faeces (S. Typhimurium and S. Drogana) and pig faeces (S. Weltevreden and S. Ughelli). Different virulence genes, viz. invA, sipA, sefA, fliC, stn and sopB were detected in Salmonella isolates using PCR-based molecular technique. Among these virulence genes, invA gene was the most prevalent one as is present in 98% Salmonella isolates followed by sopB, stn, sipA, fliC and sefA genes in 96, 86, 78, 32 and 10% Salmonella isolates, respectively. Salmonella serovars of zoonotic importance recovered from varied sources exhibited different virulence genes that may cause serious infections in animals as well as in human beings. Ultimately these virulent serovars may pose great risks to the health and production in the animals and serious health hazards in human.