MPCR检测食品中霍乱弧菌和副溶血性弧菌的研究

目的建立一种快速、敏感的方法,用于检测食品中O1群(EVC)、O139群霍乱弧菌和副溶血性弧菌。方法针对霍乱弧菌O139特异基因(T139)、肠毒素A亚单位基因(ctxA)、毒力协调A亚单位基因(tcpA),副溶血性弧菌热稳定性直接溶血素基因(tdh)为靶序列,建立MPCR检测方法,相应扩增片段依次为417bp、564bp、471bp和202bp。结果用该方法对EVC、O139VC、副溶血性弧菌的标准菌株和野生株,扩增片段出现极好的特异性,而35株非O1非O139群霍乱弧菌、沙门氏菌等未见扩增带。人工污染的罗非鱼、牡蛎、鱼肠和鳃混合物的检出限EVC为22cfug、O139为50cfug、副溶血性弧菌为65cfug,整个实验过程8～10h完成。结论实验结果表明MPCR是敏感、省时、省力的检测方法。

Research on detection of Vibrio comma and Vibro parahaemolyticus from foodstuffs using MPCR methods

Objective To establish a set of multi-PCR ( MPCR ) methods to detect Vibrio comma O1 serogroup ( EVC ) and O139 serogroup, and Vibrio parahaemolyticus rapidly and sensitively from foodstuffs. Methods Using T139 (specific gene of O139 serogroup ), ctxB and tcpA genes from V.comma, and tdh gene from V. parahaemolyticus as target sequences, we detected the anticipative amplified bands, whose sizes were relatively 417bp, 564bp, 471bp and 202bp. Results Excellent specificity of the amplified products could be found from both standard and wild strains of EVC, O139VC and V. parahaemolyticus. It also means that no amplified band was detected from total 35 strains of other bacilli, including salmonella, comma bacillus which do not belong to O1 and O139 serogroups. The detection limits of artificial contaminated samples such as tilapia flesh, oyster and mixture of tilapia intestines and gills were proved to be 22cfu/g in EVC, 50cfu/g in O139 and 65cfu/g in V. parahaemolyticus. Besides, it took only 8-10 hours to finish the whole process.Conclusion Experiment results show that MPCR is a sensitive, convenient and time saving method suitable for detection.