Model for evaluation of pathogenicity of extra-intestinal pathogenic Escherichia coli

肠外致病性大肠杆菌致病性评价模型

• 批准号: 18590442
• 负责人: OHNISHI Makoto
• 金额: $ 2.5万
• 依托单位: National Institute of Infectious Diseases
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2006
• 资助国家: 日本
• 起止时间: 2006 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18590442/
• 关键词: pathogenic bacteria; extra-intestinal pathogenic Escherichia coli; urinary tract infection; competitive growth inhibition; 病原性大腸菌; 競争的排除; PFGE; 大腸菌

Total 501 Escherichia coli isolates were collected in this study, and were analyzed by using multi locus sequence typing method (MLST). As a result, 85.9% of extraintestinal pathogenetic E. coli (ExPEC) belonged to group B2, while among commensal E. call isolates, more than half were group A/B1, and 40.2% of the isolates belonged to group B2.Based on the results of MLST analysis, group B2 isolated divided into eight sub-groups. However the isolates from the B2 subgroup did not show any significant differences on growth capacity in urine, introducing ability of IL6, and adhesive potential to epithelial cells in vitro, which are suggested as virulence characters for ExPEC.Recently it is reported that cdiA gene has a contact bactericidal activity, and the cdiA might play a role for competition with other bacteria in human intestine. Among E. call isolates from acute cystitis, 57.8% of the isolates encoded the cdiA homologue, and the cdiA widely distributed in all subgroups of group B2 as well as A/B1 and D groups. The cdiA gene was known to be associated with pathogenicity islands (PAIs) encoding papGIII and hlyA. We could show genetic variation between these PAIs, which encoded papGIII, hlyA and cdiA.To investigate which type of E. coli on phylogeny is dominant in human intestine, we collected commensal E. coil form stool of healthy volunteers. During analysis of commensal E coli on genotype and phylogeny, we found out that a certain B2-8 strain was isolated from some healthy volunteers for more than half-year as the dominant strains, indicating that this strain has a potential to adjust for the environment. As this strain did not have the cdiA, this fact implied that another mechanism might provide ability to the strains as a dominant residence in the human intestine. We need to perform further analysis for investigating mechanisms on competitive growth inhibition in the human intestine.

本研究共收集到501株大肠杆菌，采用多位点序列分型法（MLST）进行分析。结果表明，85.9%的肠道外致病性大肠杆菌（ExPEC）属于B2组，而共生菌株中一半以上属于a /B1组，40.2%的菌株属于B2组。根据MLST分析结果，分离的B2组分为8个亚组。而B2亚群分离株在尿中生长能力、il - 6导入能力和体外对上皮细胞的粘附能力等方面均未表现出显著差异，这可能是ExPEC的毒力特征。近年来有报道称cdiA基因具有接触性杀菌活性，cdiA可能与人体肠道内其他细菌竞争。在急性膀胱炎的分离株中，编码cdiA同源物的占57.8%，cdiA广泛分布于B2群、A/B1群和D群的所有亚群中。已知cdiA基因与编码papGIII和hlyA的致病性岛（PAIs）有关。我们可以显示这些PAIs之间的遗传变异，它们编码papGIII， hlyA和cdiA。为了研究大肠杆菌在人类肠道中哪种类型的系统发育优势，我们收集了健康志愿者的共生大肠杆菌粪便。在对共生大肠杆菌进行基因型和系统发育分析时，我们发现从健康志愿者中分离出的某B2-8菌株为半年多的优势菌株，表明该菌株具有适应环境的潜力。由于该菌株不具有cdiA，这一事实表明，另一种机制可能为该菌株提供了在人类肠道中占主导地位的能力。我们需要进一步分析研究竞争性生长抑制在人类肠道中的机制。

项目成果

Phylogenetic analysis of extra-intesitinal pathogenic Escherichia coli.

肠外致病性大肠杆菌的系统发育分析。

• 发表时间: 2007
• 作者: Ohnishi;Makoto;et. al.
• 通讯作者: et. al.

Phylogenetic analysis of extra-intesitinal pathogenic Escherichia coli, and characterization of the isolates.

肠外致病性大肠杆菌的系统发育分析以及分离株的表征。

• 发表时间: 2008
• 作者: Ohnishi;Makoto;et. al.
• 通讯作者: et. al.

腸管外病原性大腸菌の系統および性状解析

肠外致病性大肠杆菌的系统发育和特征

• 发表时间: 2008
• 作者: Takahashi A;Kanamaru S;Kurazono H;Kunishima Y;Tsukamoto T;Ogawa O;Yamamoto S.;大西 真
• 通讯作者: 大西 真

腸管外病原性大腸菌の系統解析

肠外致病性大肠杆菌的系统发育分析

• 发表时间: 2007
• 作者: Ohnishi;Makoto;et. al.;大西 真
• 通讯作者: 大西 真

Molecular epidemiology of uropathogenic Escherichia coli.

尿路致病性大肠杆菌的分子流行病学。

• 发表时间: 2007
• 期刊: J Infect Chemother 13(2)
• 作者: Tanaka;H.;Tamai;E.;Miyata;S.;Taniguchi;Y.;Nariya;H.;Hatano;N.;Houchi H;Okabe;A;岡部 昭延;Yamamoto S
• 通讯作者: Yamamoto S