School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia.
Helicobacter Research Laboratory, Marshall Centre for Infectious Diseases Research and Training, School of Pathology and Laboratory Medicine, University of Western Australia, Perth, WA, Australia.
Emerg Microbes Infect. 2018 Apr 11;7(1):64. doi: 10.1038/s41426-018-0065-6.
Campylobacter concisus is an oral bacterium that is associated with inflammatory bowel disease (IBD) including Crohn's disease (CD) and ulcerative colitis (UC). C. concisus consists of two genomospecies (GS) and diverse strains. This study aimed to identify molecular markers to differentiate commensal and IBD-associated C. concisus strains. The genomes of 63 oral C. concisus strains isolated from patients with IBD and healthy controls were examined, of which 38 genomes were sequenced in this study. We identified a novel secreted enterotoxin B homologue, Csep1. The csep1 gene was found in 56% of GS2 C. concisus strains, presented in the plasmid pICON or the chromosome. A six-nucleotide insertion at the position 654-659 bp in csep1 (csep1-6bpi) was found. The presence of csep1-6bpi in oral C. concisus strains isolated from patients with active CD (47%, 7/15) was significantly higher than that in strains from healthy controls (0/29, P = 0.0002), and the prevalence of csep1-6bpi positive C. concisus strains was significantly higher in patients with active CD (67%, 4/6) as compared to healthy controls (0/23, P = 0.0006). Proteomics analysis detected the Csep1 protein. A csep1 gene hot spot in the chromosome of different C. concisus strains was found. The pICON plasmid was only found in GS2 strains isolated from the two relapsed CD patients with small bowel complications. This study reports a C. concisus molecular marker (csep1-6bpi) that is associated with active CD.
短小弯曲杆菌是一种口腔细菌，与炎症性肠病（IBD）相关，包括克罗恩病（CD）和溃疡性结肠炎（UC）。短小弯曲杆菌由两个基因组种（GS）和多种菌株组成。本研究旨在鉴定区分共生和与 IBD 相关的短小弯曲杆菌菌株的分子标记。研究检测了来自 IBD 患者和健康对照者的 63 株口腔短小弯曲杆菌分离株的基因组，其中 38 个基因组在本研究中进行了测序。我们鉴定了一种新型分泌肠毒素 B 同源物 Csep1。csep1 基因存在于 56%的 GS2 短小弯曲杆菌菌株中，存在于质粒 pICON 或染色体中。在 csep1 中发现了 654-659bp 位置的 6 个核苷酸插入（csep1-6bpi）。在来自活动期 CD 患者的口腔短小弯曲杆菌菌株中（47%，7/15）发现 csep1-6bpi 的存在明显高于健康对照者（0/29，P=0.0002），而在活动期 CD 患者中 csep1-6bpi 阳性短小弯曲杆菌菌株的流行率明显高于健康对照者（67%，4/6 比 0/23，P=0.0006）。蛋白质组学分析检测到 Csep1 蛋白。在不同短小弯曲杆菌菌株的染色体中发现了 csep1 基因热点。仅在来自两个发生小肠并发症的复发 CD 患者的 GS2 菌株中发现了 pICON 质粒。本研究报告了一种与活动期 CD 相关的短小弯曲杆菌分子标记（csep1-6bpi）。
