Bidet P, Bonarcorsi S, Bingen E
Univ Paris Diderot, Sorbonne Paris Cité, EA 3105, Assistance Publique-Hôpitaux de Paris, Laboratoire de Microbiologie, Hôpital Robert-Debré, Paris, France.
Arch Pediatr. 2012 Nov;19 Suppl 3:S80-92. doi: 10.1016/S0929-693X(12)71279-4.
Extraintestinal pathogenic Escherichia coli (ExPEC) causing urinary tract infections, bacteraemia or meningitis are characterized by a particular genetic background (phylogenetic group B2 and D) and the presence, within genetic pathogenicity islands (PAI) or plasmids, of genes encoding virulence factors involved in adhesion to epithelia, crossing of the body barriers (digestive, kidney, bloodbrain), iron uptake and resistance to the immune system. Among the many virulence factors described, two are particularly linked with a pathophysiological process: type P pili PapGII adhesin is linked with acute pyelonephritis, in the absence of abnormal flow of urine, and the K1 capsule is linked with neonatal meningitis. However, if the adhesin PapGII appears as the key factor of pyelonephritis, such that its absence in strain causing the infection is predictive of malformation or a vesico-ureteral reflux, the meningeal virulence of E. coli can not be reduced to a single virulence factor, but results from a combination of factors unique to each clone, and an imbalance between the immune defenses of the host and bacterial virulence.
引起尿路感染、菌血症或脑膜炎的肠外致病性大肠杆菌（ExPEC）具有特定的遗传背景（系统发育组B2和D），并且在遗传致病岛（PAI）或质粒中存在编码毒力因子的基因，这些毒力因子参与上皮细胞黏附、穿越身体屏障（消化道、肾脏、血脑屏障）、铁摄取以及对免疫系统的抵抗。在众多已描述的毒力因子中，有两种与病理生理过程特别相关：P型菌毛PapGII黏附素与急性肾盂肾炎相关，在无异常尿流的情况下，K1荚膜与新生儿脑膜炎相关。然而，如果黏附素PapGII似乎是肾盂肾炎的关键因素，以至于在引起感染的菌株中其缺失可预测畸形或膀胱输尿管反流，那么大肠杆菌的脑膜毒力不能归结于单一毒力因子，而是由每个克隆特有的多种因素组合以及宿主免疫防御与细菌毒力之间的失衡导致的。
