基因dat对单核细胞增生李斯特氏菌的生物学特性影响  

The Effect of Gene dat on Biological Characteristics of Listeria monocytogenes

作　　者：曾海娟[1] 谢曼曼[1] 丁承超 刘武康 董庆利[1] 刘箐[1] ZENG Hai-juan, XIE Man-man, DING Cheng-chao, LIU Wu-kang, DONG Qing-li, LIU Qing(Schl. of Med. Instrum＇t ＆ Food Engin. , Uni. of Shanghai for Sci. ＆ Technol. , Shanghai 20009)

机构地区：[1]上海理工大学医疗器械与食品学院,上海200093

出　　处：《微生物学杂志》2018年第3期9-15,共7页Journal of Microbiology

基　　金：国家自然科学基金项目(31371776);微创励志创新基金项目(YS30809102);上海市研究生教育创新计划

摘　　要：单核细胞增生李斯特氏菌(Listeria monocytogenes,Lm)是一种重要的食源性致病菌,其基因dat编码D-丙氨酸氨基转移酶,可将D-谷氨酸转变为D-丙氨酸,后者是细菌细胞壁肽聚糖的组成成分。在Lm野生株EGDe actA及inlB双基因缺失株(EGDeΔactAΔinlB)的基础上,利用同源重组的方法进一步构建了缺失基因dat的菌株(EGDeΔactAΔinlBΔdat),并对该缺失菌株生长状态、毒力基因表达水平、细胞侵袭及生物被膜的形成量等基本生物学特性进行研究,运用Real Time-PCR(RT-PCR)测定Lm毒力基因的相对表达量。结果表明,基因的缺失对突变菌株的生长能力以及生物被膜形成有重要的调控作用,并导致毒力基因srt A、plc A表达量下调,VIP、inlA表达量上调,对Coca-2细胞的侵袭无影响。此缺失株的构建为进一步研究基因dat的功能提供了材料。Listeria monocytogenes（ Lm） is an important foodborne pathogens,its gene dat encoding D-alanine aminotransferase,could convert D-glutamic acid into D-alanine,and the latter is the constituent for peptidoglycan of cell wall. In this study,based on actA and inlB double gene deletion of Lm wild type strain EGDe（ EGDe ΔactAΔinlB）,a dat gene deleted strain（ EGDe ΔactAΔinlBΔdat） was constructed using homologous recombination method,and the basic biological characteristics of the deleted strain,the growth,virulence gene expression,biofilm formation and cell invasion were studied. The results showed that the gene played an important role in regulating the growth and biofilm formation of the mutant strains,and led the virulence gene expression of srt A and plc A to reduce,and the expression of VIP and inlA to rise. There was no effect in Caco-2 cells invasion. The construction of the deleted strain provided a material for further study on the function of dat gene.

关 键 词：单核细胞增生李斯特氏菌 基因敲除 生长能力 RT-PCR 细胞侵袭 生物被膜 

分 类 号：Q933[生物学—微生物学] TS201.3[轻工技术与工程—食品科学]