直接检测模拟阳性标本致病性小肠结肠耶尔辛菌

Direct detection of pathogenic Yersinia enterocolitica seeded into fecal sampl es by polymerase chain reaction

为了快速准确地检测致病性小肠结肠那尔辛菌（ＹＥ），根据该菌染色体上ａｉｌ基因顺序设计一时引物，通过聚合酶链反应直接检测模拟阳性粪便中致病性ＹＥ，该反应能扩增出１７０ｂｐ的ａｉｌ基因片段。在５００ｍｇ粪便中接种约１０￣３致病性ＹＥ即可得到阳性结果，而其他被测细菌均为阴性。运用Ｓａｎｇｅｒ双脱氧法测定了扩增产物的核苷酸顺序并证实其真实性。这一检测方法不仅特异性强、灵敏度高，而且能在１天之内出结果，还能准确地判断致病性ＹＥ的存在。

ersinia enterocolitica(YE)is widespread in nature,but only a few serotypes are involved in hu-man infections. It is essential to have an accurate and rapid method for the detection of pathogenic YE.Apair of primers based on the nucleotide sequence of the chrory1osomal ail gene were used in polymerase chain reaction to directly identify pathogenic YE in fecal samples.The PCR amplified a 170-bp fragmtnt of the ail gene. Approximately 1 000 pathogenic YE seeded into about 5 00mg of fecal sample could be extracted and amplified by PCR to yield positive result, while other tested bacteria gave negative results.The PCR product was sequenced by using dideoxy method of Sanger.The authenticity of the amplified fragment has been verified.The assay described here was not only highly specific and sensitive but also capable of providing a clear-cut result within the same day that a sample was submitted.t offered a powerful tool for establishing the precise etiology of an enteric infection and studying the relationship be-tween autoimmune diseases and pathogenic YE infections.