猪源大肠杆菌 O157：H7与 O157的差异蛋白质组学分析

Differential Proteomic Analysis between Escherichia coli Isolates O157:H7 and O157 from Swine

为了阐述O157:H7与O157的致病力差异与蛋白质表达差异之间的关系,我们利用双向电泳技术和质谱技术对大肠杆菌两类菌株之间进行蛋白质组学差异分析。菌体蛋白经双向电泳技术分离后,利用软件Image Master TM2DPlatinum7.0对所得双向电泳图谱进行差异分析并借助质谱技术对差异蛋白质点进行鉴定,获得了背景清晰、分辨率高、重复性好的菌体总蛋白的双向电泳图谱。两样品图谱差异分析结果表明,共确定了28个有效的蛋白质差异点(Av.ratio>2.0,ANOVA<0.05),经质谱鉴定将这28个差异点注释成23种蛋白质。对得到注释的23种蛋白质进行功能分类,发现7类蛋白质与致病性密切相关,即溶菌酶抑制剂、通用应激蛋白、LuxS、鞭毛蛋白以及3种外膜蛋白。本结果将为进一步研究O157:H7菌株的致病因子,探究O157:H7与其它大肠杆菌菌株的致病力差异,以及建立快速鉴别诊断O157:H7的试剂盒提供重要的依据。

Differential proteomic analysis between E. coli strains O157：H7 and O157 was carried out, in order to clarify the relationship between virulence and differentially expressed proteins of different E. coli strains. Two-dimensional electrophoresis （2-DE） was used to separate bacterial proteins and Image MasterTM 2D Platinum 7.0 software performed variation analysis of the obtained 2D maps. The differentially expressed proteins were identified by mass spectrometry. The 2D maps of bacterial total protein with clear background, high resolution and good reproducibility were obtained. The variation analysis of two samples was performed and a total of 28 differentially expressed protein spots （by fliter Av. ratio〉2.0 and ANOVA〈0.05） were detected. These protein spots were identified as 23 unique protein groups by mass spectrometry. The functional classification of annotated proteins indicated that seven kinds of proteins were closely related to bacterial virulence including C-lysozyme inhibitor, universal stress protein, LuxS, flagellin and 3 outer membrane proteins. This research provides an important proteomic basis for studying virulence factors, finding pathogenicity differences and establishing the rapid diagnosis kit of the bacterial strain O157：H7.