Rapid and Specific Detection of EnterotoxigenicEscherichia coli and Salmonella Strains byMultiplex PCR Systems

摘要

Escherichia coli and Salmonella are two of the most important food-borne bacterial pathogens. Classical identification for these strains is laborious, time-consuming, and may generate erroneous results. The purpose of this study was to develop a rapid and specific multiplex PCR (m-PCR) method to simultaneously detect heat labile enterotoxin gene of E. coli (LT ETEC) and oriC of Salmonella sp. Multiplex PCR using two pairs of primers produced specific amplicons of expected sizes of 163 bp and 425 bp from mixed populations of Salmonella sp. and LT ETEC bacterial strains, respectively. These primers were then used for the detection of food and feces with 10~1-10~2 cells/g of Salmonella and LT ETEC, followed by SCLB (selenite cystine-lactose broth, selenite cystine / lactose broth, 5/3, w/w) incubation. The presence of these two pathogens in food and feces was detectable. Finally, we used this method for the detection of 160 kinds of market-available foods and feces, and found that LT ETEC bacterial strains were detected in 2 samples (poultry and feces), and one sample (feces) by the BAM (Bacteriological Analytical Manu) method.