Genetic structure and distribution of four pathogenicity islands (PAI I536 to PAI IV536) of uropathogenic Escherichia coli strain 536
Genetic structure and distribution of four pathogenicity islands (PAI I536 to PAI IV536) of uropathogenic Escherichia coli strain 536
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DOI：
10.1128/iai.70.11.6365-6372.2002
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发表时间：
2002-11-01
影响因子：
3.1
通讯作者：
Hacker, J
中科院分区：
文献类型：
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作者：
Dobrindt, U;Blum-Oehler, G;Hacker, J
对于尿路致病性大肠杆菌菌株 536 (O6:K15:H31)，确定了三个致病岛 (PAI)（PAI I-536 至 PAI III536）及其侧翼区域（约 270 kb）的 DNA 序列，以进一步表征该菌株的毒力潜力。 PAI I-536 至 PAI III536 表现出 PAI 的典型特征，例如 (i) 与 tRNA 编码基因相关； (ii) G+C含量与宿主基因组不同； (iii) 侧翼重复结构； (iv) 一种马赛克状结构，包含大量具有已知或未知功能的功能性、截短性和非功能性假定开放阅读框（OP.F）； (v) 存在许多可移动遗传元件的片段。 PAI I-536 到 PAI III536 的大小范围在 68 到 102 kb 之间。虽然这些岛包含几个 ORF 和已知的毒力决定簇，描述了其他肠外致病性大肠杆菌 (ExPEC) 分离株的 PAI，但它们也包含编码假定毒力因子的尚未鉴定的 ORF。 PAI IV536 的遗传结构代表了最初在致病性耶尔森氏菌中鉴定出的编码铁载体系统的所谓高致病性岛的核心元件，通过样本测序进一步表征了 PAI IV536 的遗传结构。首次研究了尿路致病性大肠杆菌中的多个 PAI 序列（PAI I-536 至 PAI IV536），并广泛研究了它们在几种野生型大肠杆菌分离株中的存在。获得的结果表明这些PAI或至少其大片段在其他致病性大肠杆菌分离株中是可检测到的。这些结果支持了我们的观点，即通过水平基因转移获得大 DNA 区域（例如 PAI）是细菌病原体进化的重要因素。
For the uropathogenic Escherichia coli strain 536 (O6:K15:H31), the DNA sequences of three pathogenicity islands (PAIs) (PAI I-536 to PAI III536) and their flanking regions (about 270 kb) were determined to further characterize the virulence potential of this strain. PAI I-536 to PAI III536 exhibit features typical of PAIs, such as (i) association with tRNA-encoding genes; (ii) G+C content differing from that of the host genome; (iii) flanking repeat structures; (iv) a mosaic-like structure comprising a multitude of functional, truncated, and nonfunctional putative open reading frames (OP.Fs) with known or unknown functions; and (v) the presence of many fragments of mobile genetic elements. PAI I-536 to PAI III536 range between 68 and 102 kb in size. Although these islands contain several ORFs and known virulence determinants described for PAIs of other extraintestinal pathogenic E. coli (ExPEC) isolates, they also consist of as-yet-unidentified ORFs encoding putative virulence factors. The genetic structure of PAI IV536, which represents the core element of the so-called high-pathogenicity island encoding a siderophore system initially identified in pathogenic yersiniae, was further characterized by sample sequencing. For the first time, multiple PAI sequences (PAI I-536 to PAI IV536) in uropathogenic E. coli were studied and their presence in several wild-type E. coli isolates was extensively investigated. The results obtained suggest that these PAIs or at least large fragments thereof are detectable in other pathogenic E. coli isolates. These results support our view that the acquisition of large DNA regions, such as PAIs, by horizontal gene transfer is an important factor for the evolution of bacterial pathogens.