Salmonella, Shigella and Escherichia coli O157: H7 are major foodborne pathogens that cause gastrointestinal diseases worldwide. Apart from food contamination, fecal pollution has been consistently associated with the transmission of these pathogens, and their rapid detection in food and stools is of significance for food safety. However, a variety of factors associated with these complex samples can decrease the sensitivity and specificity of molecular-based methods for detection of these pathogens.Objectives
The aim of this study was to develop a DNA-based method for the simultaneous detection of E. coli O157: H7, Salmonella and Shigella in stool and food samples.Methods
In this study, a novel magnetic capture–multiplex polymerase chain reaction (PCR) assay was developed and its potential to detect the target pathogens in stool and food samples (including chicken, cucumbers and cooked rice) was tested.Results
The results showed that the magnetic particles (MPs) used in the study had a high capacity for bacterial adsorption. The pretreatment protocol, which included the pathogen concentration by MPs, was developed and the sensitivity of the assay was approximately 10° colony-forming unit (CFU) g−1 in food and 1–10 CFUs per stool sample, following an enrichment step. The assay could be completed within 12 h, and was comparable in performance with conventional culture methods, which require several days to complete.Conclusion
The assay combines MP-based magnetic capture with multiplex PCR, and offers an efficient, rapid, sensitive and inexpensive alternative for the routine detection of foodborne pathogenic bacteria.