pks+肠杆菌科细菌致病性的研究进展

Progress on pathogenicity research of pks-positive Enterobacteriaceae

pks基因岛是编码非核糖体肽合成酶(NRPS)、聚酮合成酶(PKS)和NRPS/PKS杂合酶的基因组岛。pks基因岛主要存在于肠杆菌科细菌中,最常存在于B2群大肠埃希菌中,并常与其他毒力因子共存。pks+大肠埃希菌能合成基因毒素colibactin,诱导细胞中的DNA双链断裂和染色体不稳定,导致细胞衰老或死亡。因此,pks+大肠埃希菌与结直肠肿瘤、脑膜炎、败血症等疾病的发生密切相关。流行病学研究也证实了pks+大肠埃希菌与多种疾病相关。除了基因毒性外,pks+大肠埃希菌也具有抗炎、镇痛和抗菌等积极作用。因此,pks+大肠埃希菌具有复杂的生物学作用。然而,pks+大肠埃希菌致病机制仍未完全清晰。本文描述了pks基因岛的概况及其在肠杆菌科细菌中的流行情况,并对pks+大肠埃希菌的生物学作用进行了概述,以期为进一步研究提供参考。

The pks genomic island encodes non-ribosomal peptide synthase(NRPS),polyketide synthases(PKS),and hybrid NRPS/PKS synthetase.This genomic island is mainly found in the members of the family Enterobacteriaceae,and is especially common in Escherichia coli of phylogroup B2 while frequently coexisting with other virulence factors.The pks-positive E.coli is able to synthesize colibactin,a genotoxic chemical compound.Thus,this pks-positive bacteria may induce the breaking of DNA double-strand and chromosomal instability,which lead to senescence and apoptosis of cells.As a result,pks-positive E.coli is positively associated with the occurrence of diseases such as colorectal neoplasms,neonatal meningitis,and septicemia.Epidemiological studies have also confirmed that pks-positive E.coli is associated with a variety of diseases.However,the exact pathogenic mechanism of pks-positive E.coli is still not understood.Despite its genotoxicity,the pks-positive E.coli also exhibits some positive effects including anti-inflammatory,analgesic,and antibiotic abilities.Therefore,the biological role of pks-positive E.coli is complicated.In this review,an overview of the pks genomic island and its prevalence in Enterobacteriaceae,as well as the biological function of pks-positive E.coli is described,aiming to provide references for further researches.