Simultaneous detection of seven foodborne Enterobacteriaceae pathogens using multiplex PCR

Abstract

Members of the family Enterobacteriaceae aremajor pathogens associated with gastrointestinal disorderscaused by the consumption of contaminated foods. This study developed a multiplex PCR targetingspecific genes for simultaneous detection and differentiationof seven major Enterobacteriaceae members, namely,Escherichia coli (uidA), Proteussp. (atpD), Salmonella sp. (invA), Enterobacter sp. (16S rRNA), Klebsiella sp. (gyrA), Klebsiella pneumoniae (rpoB) and K. oxytoca (pehX) from contaminated food samples. Four main types of food samples comprise fresh, frozen, processed frozen and processed preserved samples were examined by using simultaneous amplification of those seven-targeted genes from obtained reference strains. The multiplex PCR assay showed detection sensitivity reached 5-10 cfu for each pathogen after 2h of sample incubation on nutrient broth. Generally, the 7plex-PCR assay revealed that the most common pathogens found in 192 different food samples with high frequency was Salmonella which distributed within most of all types of food having the maximum occurrence frequency reached 6.77% in hotdog and sausage samples followed by 5.21% in fresh chicken and beef burger. The occurrence frequency % of E. coli was found to be high in chicken/beef burger samples (6.25%), and then slightly decreased to 5.21%, 4.68% and 4.17% in frozen meat, hotdog/sausage and fresh fish samples, respectively. The processed preserved (chicken/beef luncheon and pastrami) and frozen chicken possessed the lowest presence of foodborne pathogens. This study recommends the use of 7plex-PCR detection system for the rapid and accurate detection of some Enterobacteriaceae pathogens is inexpensively and thus could be used for the regular monitoring of food quality.