Rapid detection of Salmonella enterica serovar Typhi from Humans
ABSTRACT Present study was carried out to investigate Salmonella enterica serovar Typhi associated with Typhoid fever in humans. A total of six blood samples were collected from six patients (4 males and 2 females) and processed for the isolation and identification of the causative agents and their virulence determinants. Microbial investigation revealed the causative agents Salmonella enterica Serovar Typhi in all the six clinical cases. In polymerase chain reaction (PCR) assay, all the six isolates were found positive for the Invasion gene (invA; 244bp fragment), Tyvelose epimerase gene (tyv; 615bp fragment), phage-1 flagellin gene for d-antigen (fliC-d; 750bp fragment) and Vi antigen genes (viaB; 439bp fragment). This study confirms the association of virulent strains of Salmonella enterica Typhi in occurrence of the Typhoid fever in humans. Present study suggested that PCR can be a useful, high throughput diagnostic tool for the rapid detection of Salmonella enterica Serovar Typhi.
- SourceAvailable from: Ganeshkumar Arumugam[show abstract] [hide abstract]
ABSTRACT: The present research work was carried out for the screening of virulence genes associated with the Salmonella enterica isolated from commercial food stuffs by polymerase chain reaction (PCR). A total of 134 samples of commercial food stuffs constituting of raw meats of poultry, pork, beef, raw eggs, dairy and bakery products were purchased from the departmental stores, supermarkets and local butcher shops of Salem, Erode and Coimbatore districts of Tamil Nadu, India. Samples were aseptically processed for the isolation of S. enterica through broth enrichment methods. PCR was performed with various virulence genes specific primers of S. enterica. Microbiological investigations resulted in Salmonella isolates in 35 (26.11%) samples. In PCR, invasive gene (invA; 244bp), Salmonella enterotoxin gene (stn; 617bp), plasmid encoded fimbriae (pefA; 700bp), Salmonella Enteritidis fimbriae (sefC; 1103bp) and Salmonella plasmid virulence C gene (spvC; 571bp) were detected in 100%, 100%, 51.42%, 25.71% and 42.85% isolates respectively. Present study suggested that invA and stn virulence genes are much conserved in S. enterica isolated from commercial food stuffs and could be used independently as a gene marker for the rapid detection of the virulent strains of S. enterica. The prevalence of spvC gene is restricted into the isolates of a few definite sources. The result emphasized the risk of transferring these zoonotic organisms to human via food chain is impending danger for the mankind.Biosciences Biotechnology Research Asia. 02/2012; Vol. 9(1):363-369.