Chiang Mai Journal of Science

 Oligonucleotide array hybridization-based methods can be used for high-throughput foodborne pathogens screening. In this investigation, screenings of suitable probes for specific detection of foodborne pathogens prevalence in processed fresh and frozen chicken meat were performed using post-PCR labeled target regions. The hybridization signals of non-radioactive labeling with digoxigenin (DIG), incorporated into the purified PCR target regions could be observed by visual inspection. Target regions of 16S rRNA genes of Clostridium perfringens, Escherichia coli, Listeria monocytogenes, Salmonella spp., and Staphylococcus aureus were used. The invA gene specific for Salmonella spp., and the prfA gene specific for L. monocytogenes were also used as target genes. The optimum concentration of the oligonucleotide probes was found to be 200 pmol. The detection system in this investigation were carried out to detect genomic DNA extracted from pure cultures of multiple target bacteria at as low as one nanogram (equivalent to 2 × 10⁵ copies of bacterial genome) of each in mixed samples. The labeled target regions of 16S rRNA gene generated by post-PCR labeling methods could be used to differentiate the target bacteria at the genus level. This developed protocol could be used for multiple target bacteria detection with cost effective compared to modern oligonucleotide microarray technique.