RESUMEN

OBJECTIVE: To develop an assay for the simultaneous detection of 7 common foodborne pathogens with xMAP liquid chip in a single-tube reaction. METHODS: Seven specific primers and probes were designed and synthesized based on the target gene sequences from GenBank. Target bacterial sequences were amplified by asymmetric PCR. The biotinylated products were hybridized to seven probe beads in a multiplex reaction and analyzed by using streptavidin conjugated to a fluorescent reporter molecule. The developed liquid chip xMAP assay was used to test 140 strains of bacteria and then 56 food samples. RESULTS: No cross-reaction and false signals were observed. The detection limit was 1 - 100 pg and 10(5) - 10(6) cfu/ml. The results tested by xMAP were in accordance with the traditional culture method. CONCLUSION: The processing of xMAP liquid chip assay, including DNA preparation and sample detection, could be finished within 3.5 hours and could be applied to the classification and identification of foodborne pathogens in the food safety monitoring.

Asunto(s)

Técnicas Bacteriológicas , Microbiología de Alimentos/métodos , Salmonella/aislamiento & purificación , Staphylococcus aureus/aislamiento & purificación , Vibrio parahaemolyticus/aislamiento & purificación , Bacterias/genética , Bacterias/aislamiento & purificación , Escherichia coli O157/genética , Escherichia coli O157/aislamiento & purificación , Contaminación de Alimentos , Microesferas , Técnicas de Amplificación de Ácido Nucleico , Hibridación de Ácido Nucleico , Sondas de Oligonucleótidos , Reacción en Cadena de la Polimerasa/métodos , Salmonella/genética , Staphylococcus aureus/genética , Vibrio parahaemolyticus/genética