Detection of eight foodborne bacterial pathogens by oligonucleotide array hybridization

BACKGROUND: Simultaneous and rapid detection of multiple foodborne bacterial pathogens is important for the prevention of foodborne illnesses. OBJECTIVE: The aim of this study was to evaluate the use of 16S rDNA and 23S rDNA sequences as targets for simultaneous detection of eight foodborne bacterial pathogens. METHODS: Nineteen bacterial oligonucleotide probes were synthesized and applied to nylon membranes. Digoxygenin labeled 16S rDNA and 23S rDNA from bacteria were amplified by PCR using universal primers, and the amplicons were hybridized to the membrane array. Hybridization signals were visualized by NBT/BCIP color development. RESULTS: The eight intestinal bacterial pathogens including Salmonella enterica, Escherichia coli, Bacillus cereus, Vibrio cholerae, Shigella dysenteriae, Staphylococcus aureus, Listeria monocytogenes, and Enterococcus faecalis were appropriately detected in a panel of oligonucleotide array hybridization. The experimental results showed that the method could discriminate the bacterial pathogens successfully. The sensitivity of oligonucleotide array was 10(3) CFU/ml. CONCLUSION: This study showed that 16S rDNA and 23S rDNA genes had sufficient sequence diversity for species identification and were useful for monitoring the populations of foodborne pathogenic bacteria. Furthermore, results obtained in this study revealed that oligonucleotide array hybridization had a powerful capability to detect and identify the bacterial pathogens simultaneously.