一株未知黏附基因型的尿道致病性大肠埃希菌UPEC4030株的基因分析  

Genomic analysis of an unkown pap genotype from uropathogenic Escherichia coli 4030 strain

作　　者：吴庆刚[1] 张敬平[1] 陈锦英[2] 郑明寰[3] 尤凤兴[1] 姜永[1] 

机构地区：[1]无锡市疾病预防控制中心,214023 [2]天津医科大学基础医学院 [3]中国疾病预防控制中心传染病预防控制所

出　　处：《中华流行病学杂志》2008年第11期1123-1127,共5页Chinese Journal of Epidemiology

基　　金：卫生部科研基金资助项目（WKJ2006-2-10）

摘　　要：目的比较尿道致病性大肠埃希菌UPEC4030株papG和papA基因与相关序列的差异，以明确UPEC4030 papA基因变异情况及与papG的组合形式，确定是否为未知基因型。方法采用基因克隆测序方法，分别对UPEC4030株papG和papA基因进行序列分析，并与相关序列进行比较。结果UPEC4030 papA由722个碱基对组成，编码192个氨基酸的多肽。与10个基因型UPEC papA核苷酸序列和推导的氨基酸序列同源性比较，分别为36．11％～77．95％和22．20％～78．34％；与papA基因分型多重PCR引物序列比较，下游分型引物在UPECA030 papA相应位置上的序列同源性只有10．00％～66．67％，表明该菌株papA确实为未知的基因型。UPECA030菌株papG全基因片段由1100个碱基组成，编码337个氨基酸的多肽，其核苷酸及推导的氨基酸序列与Ⅱ型papG代表株UPECIA2相比较，同源性分别为99．00％和99．11％，表明UPEC4030 papG属于Ⅱ型。结论UPEC4030 papA为未知的基因型，其papG属于Ⅱ型。Objective To investigate the differences between the sequences of papa and papG of UPEC4030 strain and the related genes, to better understand the genetic variation of UPEC4030 papa and its combination forms with papG so as to identify if it was a new genotype. Methods Cloning and sequencing methods were used to analyze the sequences of papG and papa of UPEC4030 strain and to compare their related sequences. Results Through sequence analysis of papa, it was revealed that there was a 722 bp gene, encoding 192 amino acid polypeptide. The overall homology of the papa genes between UPEC4030 and the standard strains of ten F types were 36.11%-77.95% and 22.20%-78.34% at nucleotide and deduced amino acid levels. Homology between the sequences of reverse primers and the corresponding sequence of UPEC4030 papA was 10.00%-66.67%. The results confirmed that UPEC4030 strain contained a novel papa variant. Through sequence analysis of UPEC4030 papG, we revealed a 1100 bp gene, encoding 337 amino acid polypeptide. The homology of the papG genes between UPECA030 and UPEC IA2, the standard strain, was 99.00% at nucleotide level and 99.11% at deduced amino acid and UPEC4030 strain carried class Ⅱ genotype of papG. Conclusion UPECA030 strain contained an unknown papA variant or the new genotype and carried class Ⅱgenotype of papG. The pathogenic mechanism and epidemiology call for further study.

关 键 词：尿道致病性大肠埃希菌 基因测序 未知基因型 

分 类 号：R378[医药卫生—病原生物学]