Abstract: Objective: To establish a method for detecting pathogenic bacteria quickly and accurately combinedly using DNA chip and tyramide signal amplification method. Methods: According to the sequences of 16S and 23S rDNA gene, common primer pairs and specific probes were designed. The primer pairs labeled with biotin group were used for PCR amplification, and then PCR products were hybridized with probes on the DNA chip. After the above process, the coloration was done using tyramide-Cy3. Finally, hybridization images were scanned by a fluorescence scanner. Results: Eight pathogenic bacteria were detected using this assay described here. The targets were Salmonella spp, Shigella spp, Vibrio parahaemolyticus, Campylobacter jejuni, Escherichia coli O157:H7, Listeria monocytogenes, Vibrio cholera, Bacillus cereus. The sensitivity of this assay was approximately 5 ×102 CFU/mL for Vibrio parahaemolyticus. When 20 double-blind samples were detected, the results were in accordance with those of conventional methods. Conclusion: The specific and sensitive assay reported in the article can be applied for disease controlling and clinical diagnosis.   

Key words: pathogenic bacteria, DNA chip, tyramide signal amplification