种植蔬菜中非O157产志贺毒素大肠埃希菌污染传递特征研究

Outbreaks of non-O157 Shiga toxin-producing Escherichia coli ( non-O157 STEC ) infection linked to vegetables are major severe food-borne illnesses which have been concerned to the important food safety issues globally in recent years. The study is carried on non-O157 STEC contamination in vegetable planting to investigate its characteristics and changes during the transmission. Isolation and quick serotyping methods are developed to recover the isolates during different process. Isolates from the different origins are compared in virulence profile, environmental fitness (antimicrobial resistance and carbon nutrition profile) and pathogenicity. The genetic correlation of all isolates is analyzed by PFGE and MLVA genotyping methods which can be used to track transport relevant to produce contamination. The results of this study will fill the gap of contamination, characteristics changes, genetic correlation of non-O157 STEC at different stages of transmission in vegetable planting. It also will provide a theoretical basis to prevent and control non-O157 STEC contamination of vegetable planting, and protect the health of consumers.

非O157产志贺毒素大肠埃希菌 ( STEC ) 污染蔬菜导致严重的食源性疫情暴发，是近年来全球范围内普遍关注的、重要的食品安全问题。本项目以非O157 STEC为研究对象，开展蔬菜种植过程中该菌的污染传递特征的研究。优化分离培养方法，建立快速血清鉴定方法，获得蔬菜种植过程中不同环节的菌株污染数据；比较不同环节来源菌株间毒力基因型、环境适应性（耐药性和碳源、氮源利用）及致病性差异；运用脉冲场凝胶电泳和多位点可变数目串联重复序列分型方法建立数据库比较菌株间遗传相关性并进行追溯调查；从而填补我国可生食蔬菜非O157 STEC污染传递特征变化及遗传相关性的空白。该课题的研究将为制定可生食蔬菜种植业非O157 STEC的预防控制措施提供理论依据，对保护消费者健康具有重要意义。

非O157产志贺毒素大肠埃希菌 ( STEC )导致严重的食源性疫情暴发。本项目建立复杂基质中非O157 产志贺毒素大肠埃希菌（Shiga toxin-producing Escherichia coli，STEC）的分离及鉴定，可以实现20小时内快速检测；在四省（市）进行涵盖养殖场、零售食品及腹泻病人中以致泻性大肠埃希菌(diarrheagenic Escherichia coli, DEC)为主食源性致病菌的污染来源及分布特征；阐明不同来源致泻性大肠埃希氏菌分离株的重要表型、基因型、致病力等差异；运用全基因组序列分析技术发现高致病性耐药STEC菌株耐药机制及传播特征。本项目按研究计划完成相关任务，课题负责人以第一标注发表SCI论文4篇（为第一作者或责任作者），以第二标注发表SCI1篇（并列第一作者），项目负责人获得北京市人才项目优秀人才培养资助-青年拔尖个人。