安徽省114株EHECO157∶H7菌株毒力因子基因的初步分析

目的　对安徽省近几年分离的肠出血性大肠杆菌O157∶H7(EHECO157∶H7)菌株的毒力因子基因进行实验室检测 ,以分析和研究肠出血性大肠杆菌O157∶H7的毒力特征和致病特性。方法　采用聚合酶链反应(PCR)检测EHECO157∶H7的两种重要的毒力因子志贺样毒素 (SLT)和溶血素 (hly)的特异性基因片段 ,并辅以血清学试验、生化试验进行菌株的生物学特性鉴定。结果和结论　检测结果显示 ,有 63.2%的EHECO157∶H7菌株携带SLT、hly基因 ,动物源的菌株以家禽较高 ,家畜次之 ,3株源自腹泻病人的菌株毒力因子基因携带率为33.3% ,说明分离的EHECO157∶H7菌株具有较强的致病性 ;114株菌株中,有 14.0%的菌株在 24h内发酵山梨醇 ,发酵山梨醇菌株的毒力因子基因携带率 18.8% ,显著低于不发酵菌株的 70.4% ,显示出山梨醇发酵特性变异与毒力因子基因缺失之间具有一定的关联性。

Primary Analysis of Virulent Genes of 114 Strains EHEC O157:H7 in Anhui Province

To analyze and study the virulent Characteristic and the pathogenesis of EHEC O157∶H7; and to test the virulent genes of EHEC O157∶H7 isolated in Anhui Province. Methods Using PCR to test the specific gene fragment of two virulent factors (SLT and hly) of EHEC O157∶H7; and using serology test and biochemical test to identify to biological character of the strains. Result 63.2% of EHEC O157∶H7 strains carried SLT and hly genes, among the animal original strains livestock's given the highest rate,the rate of poultry was the second.It showed that the patho-genicity of EHEC O157∶H7 was powerful.14.0% of the 114 isolated strains metabolized sorbitol in 24 hours,18.8% of the strains that metabolism sorbitol carried these genes,which was lower than that did not metabolize sorbitol(70.4%),it showed some relevance between the mutation of metabolism sorbitol and lack of virulent genes.