Comparison of multiplex polymerase chain reaction and immunoassay to detect Salmonella spp., S. Typhimurium, and S. Enteritidis in Thai chicken meat

Abstract

The multiplex PCR (mPCR), enzyme-linked immunosorbent assay (ELISA) and immunomagnetic separation enzyme-linked immunosorbent assay (IMS-ELISA) were developed for the detection of Salmonella spp. and two specific serovars S. Typhimurium and S. Enteritidis. The detection limits of the mPCR without the pre-enriched step was at 105 cfu/ml, whereas developed immunoassays demonstrated positive results at 105, 106, and 107 cfu/ml by ELISA and at 104, 104, and 106 cfu/ml by IMS-ELISA for detecting Salmonella spp., S. Typhimurium, and S. Enteritidis, respectively. The mPCR did not produce any nonspecific amplified products when tested against other related species of bacteria. In this study, the developed IMS-ELISA gave more sensitivity but less specificity than the mPCR assay. The methods are useful for the rapid detection of salmonellae in naturally infected chicken meat in Thailand.