SKLMM Workshop

报告题目：人体肠道双歧杆菌获得性耐药基因及其转移特性研究

报告人简介：
  杨虹，上海交通大学生命科学技术学院教授、博士生导师。1993年7月于江南大学（原无锡轻工业学院）发酵工程专业获得工学博士学位。1999-2006年先后在德国Hannover大学、日本筑波大学和加拿大LAVAL大学留学和访问研究。作为项目负责人曾主持了多项国家自然科学基金项目、国家科技部项目、上海市和企业委托等研究项目，并获得了教育部科技进步二等奖、上海高校优秀青年教师等荣誉。目前其主要研究方向：（1）益生乳酸细菌：益生双歧杆菌和乳杆菌的定向筛选及应用研究、双歧杆菌和乳杆菌等的降胆固醇和抗氧化等功能基因的克隆和异源表达研究、菌株的热应激和酸应激机制研究、耐药基因的横向漂移研究、有害产物的检测和产生机制研究；（2）环境微生物：富营养化湖泊中总浮游细菌、蓝藻和溶藻细菌等多个微生物群落结构分析及变迁规律的研究，溶藻细菌筛选及应用、溶藻活性物质分离纯化、溶藻功能基因的克隆、和溶藻机制的研究。

报告摘要：       
        With the abuse of macrolide, lincosamide, and streptogramin (MLS) antibiotics, the traditionally safe bifidobacterial strains in the human intestine could serve as a reservoir of MLS resistance genes. In the present study, the erm(X) gene was detected in 29 MLS-resistant strains and one MLS-susceptible strain among 92 bifidobacterial strains of human origin; this study is the first to report erm(X)-mediated MLS resistance in Bifidobacterium pseudocatenulatum, Bifidobacterium breve and Bifidobacterium 
bifidum. The insertion sequences (ISs) flanking antibiotic resistance (AR) genes (i.e., the genetic environment of AR genes) could contribute to the horizontal spreading of AR. However, the potential transferability of erm(X) in bifidobacteria has not been previously verified. Here, we retrieved four genetic environments (I-IV) of erm(X) from 30 erm(X)-positive bifidobacterial strains; this study is the first to identify the erm(X) gene in three new genetic environments (II, III and IV) in bifidobacteria. The erm(X) gene was individually flanked by IS1249 or IS3 in genetic environments I, II and IV and was simultaneously flanked by IS1249 and IS3 elements in genetic environment III. Only the transfer of erm(X) from genetic environment III, simultaneously flanked by IS1249 and IS3 elements was successfully observed in filter mating experiments. These findings suggest a synergic effect of IS1249 and IS3 elements in the transfer of erm(X) in bifidobacteria and further reveal that the various genetic environments of erm(X) result in significant differences in the transferability oferm(X) in bifidobacteria.

时  间：    2018年12月7日(星期五)12:30-13:45

地  点：    闵行校区生物药学楼树华多功能厅（800号）

主持人： 唐鸿志 教授

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