多重PCR同时检测粪便中的志贺菌、侵袭性大肠埃希菌和O－1群霍乱弧菌的致病基因

本研究建立一种快速标本处理和多重聚合酶链反应（ＰＣＲ）诊断方法，在一次ＰＣＲ反应中同时扩增志贺菌、侵袭性大肠埃希菌的侵袭性质粒（ｉａｌ）基因和Ｏ－１群霍乱弧菌的霍乱毒素Ａ亚单位（ｃｔｘＡ）基因。扩增产物经电泳，出现与已知阳性对照细菌条带大小一致的条带即判断为该标本阳性。对一组经常规培养生化鉴定法诊断为霍乱的２６份腹泻病人粪便标本检测后，ＰＣＲ法有２４例检测到ｃｔｘＡ基因，ＰＣＲ阴性的２例为非Ｏ－１群；对另一组５６例粪标本亦进行了检测。本方法具有简便、快速、特异、经济和不须培养等特点，宜于临床应用。

SIMULTANEOUS DETECTION OF VIRULENCE GENES OF SHIGELLA OR ENTEROINVASIVE ESCHERICHIA COLI AND VIBRIO CHOLERAE IN DIARRHEAL STOOL USING RAPID MULTIPLEX PCR

A procedure of simultaneous detection of virulence genes in diarrheal stools was established by rapid multiplex PCR.In a single tube, the following virulence genes of invasion associated loci (ial) of the large plasmid of Shigella or EIEC,and cholerae toxin subunit A (ctxA) of Vibrio cholerae were amplified.By referring the DNA marker of known size of DNA fragments,infection or coinfection of the bacteria is determined if the same size bands are seen via electrophoresis.A total of 26 strains of V. cholerae was isolated from stool samples of patients with acute secretory diarrhea in Shanghai in 1994 by conventional assay.24 strains of V. cholerae O 1 gave positive results by PCR,and 2 isolates of non O 1 strains were negative.Another group of 56 stool samples were also amplified.This method is highly specific,sensitive,universal,rapid,simple as well as economical,and reduces cross contamination for diagnosis of infectious diarrhea.