Validated PCR Assay for the Routine Detection of Salmonella in Food

Abstract

We developed a rapid and reliable PCR assay with genus-specific primers for the detection of Salmonella in food samples. With these primers, no primer-specific amplicons were detected when challenged with cultures of microorganisms other than salmonellae, and positive results, i.e., Salmonella-specific bands, were obtained with pure cultures of all 125 Salmonella isolates tested, which represented 100 serovars. The PCR assay was optimized using both pure cultures and artificially inoculated food samples. The assay results were compared with those of the Australian standard culture methods, using more than 500 "naturally" contaminated food samples, over a period of 9 years. Food samples were subjected to nonselective preenrichment in buffered peptone water followed by selective enrichment in Rappaport Vassiliadis (RV) broth and mannitol selenite cystine (MSC) broth. A simple sample preparation method was developed based on concentrating bacterial cells from 1 ml of RV or MSC broths. The PCR results were in perfect agreement with the results of the standard culture methods; no false-positive or false-negative results were obtained. However, the PCR assay was extremely rapid, and results could be obtained within 4 h of testing of enrichment broths.

A review of the ecology, colonization and genetic characterization of Salmonella enterica serovar Sofia, a prolific but avirulent poultry serovar in Australia

“…and included S. Sofia in the control strains (Pavic, Groves, Bailey, & Cox, 2010). A PCR assay for detection of Salmonella from foods after culture enrichment was developed by Bansal et al (2006). All 125 Salmonella isolates representing 100 Salmonella serovars, including clinical isolates commonly found in Australia along with the atypical S. Sofia and a number of subsp.…”

The Use of Molecular Methods for Detecting and DiscriminatingSalmonellaAssociated with Foods — A Review

“…Given that the genus Salmonella is an extremely polymorphic and diverse group comprising approximately 2,500 serotypes, Bansal et al (2006) undertook an extensive validation of the PCR for the routine detection of Salmonella in a variety of foods that include raw meats, poultry, cooked meat products, seafood, vegetables, and dairy products. The primers ST11/ST15 (Table 2) from were used.…”

Application of PCR for rapid detection and serotyping of Salmonella spp. from porcine carcass swabs following enrichment in semi-solid agar

“…To reduce detection times, several PCR methods have been described for the detection of Salmonella spp. from a variety of samples such as pork carcass swabs, chicken carcass rinses, beef, chicken, pork and raw milk that have undergone initial enrichment steps in Buffered Peptone Water (BPW) and RVS (Yeh, Chen, Liao, Chang, & Lo, 2002;Bansal, Gray, & McDonell, 2006;Catarame, O' Hanlon, McDowell, Blair & Duffy, 2006;Prendergast et al, 2008Prendergast et al, , 2009 or MSRV (Chen et al, 1997;Liao & Shollenberger, 2003). PCR assays have targeted genes such as invA, the 16S rRNA gene, agfA or virulence associated plasmids, viaB and sefA (Patel, Bhagwat, Sanglay, & Solomon, 2006).…”