食品中大肠埃希菌中耐药1型整合子检测及多态性分析

Detection and analysis of polymorphisms of class 1 integrons in food-born Escherichia coli

目的:了解食品中大肠埃希菌中耐药1型整合子的存在频率,并分析1型整合子可变区DNA碱基大小,以探讨食品中大肠埃希菌耐药基因的携带情况和多态性。方法:普通PCR检测50株分离于食品的大肠埃希菌1型整合子,并采用长片段PCR方法扩增1型整合子可变区序列,计算可变区DNA碱基长度。结果:50份样本有17份检出1型整合子结构(34%),长片段PCR扩增1型整合子DNA平均长度为2321 bp,根据可变区分子量大小判断,共有5种整合子结构。结论:食品中大肠埃希菌携带1型整合子阳性较普遍,并具有一定的多态性。

Objective：To investigate the class 1 integrons in food - born Escherichia coli and analyze the DNA size of variable region in class 1 integrons to get knowledge of carriage rate and polymorphisms of class 1 integrons. Methods： Class 1 integrons in 50 strains of Escherichia coli was detected with PCR. The variable region was amplified by long PCR. DNA size of the variable region was calculated. Results：Seventeen out of 50 strians were identified being class 1 positive （34%）. Long PCR showed that the class 1 integron was 2321 bp in length averagely. There were 5 kinds of class 1 integrons judged by size of the variable region. Conclusion：High incidence of class 1 integrons with polymorphisms has been found in strains of Escherichia coli.