In order to improve the current methods for molecular biological detection of Shigella,primers were designed respectively according to the genes of invC,rfc,wbgZ and rfpB of Shigella,and a PCR method was established to identify Shigella,S.flexneri,S.sonnei and S.dysenteriae.At the same time,taking the primers designed from ompA gene as a reference,the method was verified by specific and artificial inoculation tests.The results showed that specific reaction were observed in both 17 Shigella strains and 19 non-Shigella strains.When the enrichment broth was detected directly by PCR,the detection limit of Shigella in instant food was 1~3 cfu/(25 g·mL-1),including pasteurized milk,ice cream,acidophilus milk,cheese,cooked meat and sau sage,and the detection limits of Shigella in raw milk,raw meat and powdered milk were ≤ 12,27 and ≤ 27 cfu/(25 g·mL-1),respectively. When PCR was done after isolation and culture of suspected bacteria,the detection limit of all samples was 1-3 cfu/(25 g·mL-1),which was consistent with the traditional culture method. In conclusion,the PCR method was rapid, sensitive and specific,and it was suitable for routine analysis of Shigella.%为弥补目前志贺氏菌分子生物学检测方法的不足,根据志贺氏菌的invC?rfc?wbgZ 和rfpB 等基因,分别设计引物建立了鉴定志贺氏菌属?福氏志贺氏菌?宋内志贺菌和痢疾志贺氏菌的PCR 方法.同时,以根据ompA 基因设计的引物作为参照,通过特异性试验和人工接种试验等,对该方法进行验证.结果显示:17 株志贺氏菌和 19 株非志贺氏菌均出现100% 的特异性反应;对增菌肉汤直接进行PCR 检测时,在消毒奶?冰淇淋?酸奶?奶酪?熟肉和香肠等即食食品中的志贺氏菌检出限为1~3 cfu/(25 g ? mL-1),在原奶?生肉和奶粉中的检出限分别为≤ 12?27 和≤ 27 cfu/(25 g ? mL-1);分离培养后再对可疑菌落进行PCR 鉴定时,所有样品检出限均为1~3 cfu/(25 g ? mL-1),与传统培养法检出限一致.结果表明,该PCR 方法快速?敏感?特异,适合用于志贺氏菌的常规检测分析.
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