Medical Microbiology Department, College of Medicine, Al-Nahrain University, Baghdad, Iraq.
Sci Rep. 2024 Aug 2;14(1):17966. doi: 10.1038/s41598-024-68867-w.
Colibactin, is a cyclomodulin expressed from polyketide synthase (pk) genomic islands. These bacterial toxins interfere with the eukaryotic cell cycle and induce DNA damage. The aim of the present study was to investigate the prevalence of colibactin production among E. coli strains recovered from different infections, determine the similarity of clb nucleotide sequences, and identify genotype of isolates using multilocus sequence typing(MLST). This was a prospective, cross-sectional study conducted from January 2022 to February 2023. A total of 117 clinical isolates were obtained from various sample types collected from outpatients and inpatients recruited to the Department of Bacteriology Labs in different hospitals in Baghdad, Iraq. clbA/clbR, clbB and clbP/clbQ were detected via conventional PCR, and partial sequencing of amplicons was performed via Sanger sequencing. For select isolates, MLST genotyping was performed. The most common phylogenetic group was B2 (61/106; 57.54%). Among the E. coli strains, 27/106 (25.47%) were clb + ve, and the most common type was clbB (13/27; 48.14%). Analysis of the partial sequencing of clb among the strains revealed high molecular similarity. Genotyping of 37 selected E. coli strains via MLST revealed 28 different genotypes. There was a high prevalence of colibactin production in phylogroup B2, and it seems that the clb + ve strains had conserved molecular structures. There was high genetic diversity among the strains tested.
产肠毒素大肠埃希菌是一种由聚酮合酶（PK）基因岛表达的环调节素。这些细菌毒素干扰真核细胞周期并诱导 DNA 损伤。本研究旨在调查不同感染中分离的大肠埃希菌菌株产肠毒素的流行情况，确定 clb 核苷酸序列的相似性，并使用多位点序列分型（MLST）鉴定分离株的基因型。这是一项从 2022 年 1 月至 2023 年 2 月进行的前瞻性、横断面研究。从伊拉克巴格达不同医院的细菌学实验室收集的各种样本类型中获得了 117 株临床分离株。通过常规 PCR 检测 clbA/clbR、clbB 和 clbP/clbQ，通过 Sanger 测序对扩增子的部分序列进行测序。对部分分离株进行 MLST 基因分型。最常见的进化群是 B2（61/106；57.54%）。在大肠埃希菌菌株中，27/106（25.47%）为 clb+ve，最常见的类型为 clbB（13/27；48.14%）。对菌株中 clb 的部分测序分析显示，分子相似性很高。通过 MLST 对 37 株选定的大肠埃希菌菌株进行基因分型，发现了 28 种不同的基因型。B2 进化群中肠毒素的产生率很高，似乎 clb+ve 菌株具有保守的分子结构。测试的菌株具有很高的遗传多样性。
