Laboratory of Microbiology, Oita Prefectural Institute of Health and Environment, Department of Public Health, Faculty of Medicine, Oita University, Oita 870-1117, Japan.
J Clin Microbiol. 2010 Nov;48(11):4107-14. doi: 10.1128/JCM.00677-10. Epub 2010 Sep 15.
The relationship to diarrhea of genes located on the pathogenicity islands (PAI) other than the locus of enterocyte effacement (LEE) was investigated. Enteropathogenic Escherichia coli (EPEC), the retention of espC on the EspC PAI, the OI-122 genes (efa1/lifA, nleB), the phylogenetic marker gene yjaA, and the bundle-forming pilus gene bfpA on the EPEC adherence factor (EAF) plasmid were studied. E. coli strains carrying the intimin gene (eae) without the Shiga toxin gene, isolated from patients with diarrhea (n = 83) and healthy individuals (n = 38) in Japan, were evaluated using PCR. The genotypes of eae and espC were identified by heteroduplex mobility assay (HMA). The proportions of strains isolated from individuals with and without diarrhea that carried these genes were as follows: bfpA, 13.3 and 7.9%, respectively; espC, 25.3 and 36.8%; efa1/lifA, 32.5 and 13.2%; nleB, 63.9 and 60.5%; yjaA, 42.2 and 55.3%. Statistical significance (P < 0.05) was achieved only for efa1/lifA. The proportion of strains lacking espC and carrying efa1/lifA was higher for patient-derived strains (30.1%) than for strains from healthy individuals (13.2%), but the difference was not significant. Strains carrying both espC and efa1/lifA were rare (2 strains from patients). Statistical analyses revealed significant relationships between espC and yjaA and between efa1/lifA and nleB, as well as significant inverse relationships between espC and efa1/lifA and between efa1/lifA and yjaA. espC was found in eae HMA types a1, a2, and c2, whereas efa1/lifA was found in types b1, b2, and c1. In addition, 6 polymorphisms of espC were found. The espC, yjaA, efa1/lifA, and nleB genes were mutually dependent, and their distributions were related to eae type, findings that should be considered in future epidemiological studies.
研究了致病性岛（PAI）上除肠上皮细胞消失（LEE）基因座以外的基因与腹泻的关系。研究了肠致病性大肠杆菌（EPEC）、EspC PAI 上的 espC、OI-122 基因（efa1/lifA、nleB）、EPEC 黏附因子（EAF）质粒上的 phylogenetic marker 基因 yjaA 和束形成菌毛基因 bfpA。使用 PCR 评估了从日本腹泻患者（n=83）和健康个体（n=38）中分离的携带 intimin 基因（eae）而无志贺毒素基因的大肠杆菌菌株。通过异源双链迁移分析（HMA）鉴定 eae 和 espC 的基因型。从腹泻和无腹泻个体中分离的菌株携带这些基因的比例如下：bfpA，分别为 13.3%和 7.9%；espC，分别为 25.3%和 36.8%；efa1/lifA，分别为 32.5%和 13.2%；nleB，分别为 63.9%和 60.5%；yjaA，分别为 42.2%和 55.3%。仅 efa1/lifA 达到统计学显著性（P<0.05）。源自患者的菌株缺失 espC 并携带 efa1/lifA 的比例（30.1%）高于源自健康个体的菌株（13.2%），但差异无统计学意义。同时携带 espC 和 efa1/lifA 的菌株很少（2 株来自患者）。统计分析显示 espC 与 yjaA 之间、efa1/lifA 与 nleB 之间存在显著关系，espC 与 efa1/lifA 之间以及 efa1/lifA 与 yjaA 之间存在显著负相关。espC 存在于 eae HMA 类型 a1、a2 和 c2 中，而 efa1/lifA 存在于类型 b1、b2 和 c1 中。此外，还发现了 espC 的 6 种多态性。espC、yjaA、efa1/lifA 和 nleB 基因相互依赖，其分布与 eae 类型有关，这些发现应在未来的流行病学研究中加以考虑。
