a Department of Medicine, Division of Gastroenterology , University of California San Francisco , San Francisco , CA , USA.
b Department of Infectious Diseases , Aalborg University Hospital , Aalborg , Denmark.
Gut Microbes. 2019;10(1):34-44. doi: 10.1080/19490976.2018.1472201. Epub 2018 Sep 25.
Campylobacter concisus has been isolated from patients with gastroenteritis and inflammatory bowel disease (IBD), as well as healthy subjects. While strain differences may plausibly explain virulence differentials, an alternative hypothesis posits that the pathogenic potential of this species may depend on altered ecosystem conditions in the inflamed gut. One potential difference is oxygen availability, which is frequently increased under conditions of inflammation and is known to regulate bacterial virulence. Hence, we hypothesized that oxygen influences C. concisus physiology. We therefore characterized the effect of microaerophilic or anaerobic environments on C. concisus motility and biofilm formation, two important determinants of host colonization and dissemination. C. concisus isolates (n = 46) sourced from saliva, gut mucosal biopsies and feces of patients with IBD (n = 23), gastroenteritis (n = 8) and healthy subjects (n = 13), were used for this study. Capacity to form biofilms was determined using crystal violet assay, while assessment of dispersion through soft agar permitted motility to be assessed. No association existed between GI disease and either motility or biofilm forming capacity. Oral isolates exhibited significantly greater capacity for biofilm formation compared to fecal isolates (p<0.03), and showed a strong negative correlation between motility and biofilm formation (r = -0.7; p = 0.01). Motility significantly increased when strains were cultured under microaerophilic compared to anaerobic conditions (p<0.001). Increased biofilm formation under microaerophillic conditions was also observed for a subset of isolates. Hence, differences in oxygen availability appear to influence key physiological aspects of the opportunistic gastrointestinal pathogen C. concisus.
弯曲菌属（Campylobacter concisus）已从肠胃炎和炎症性肠病（IBD）患者以及健康受试者中分离出来。虽然菌株差异可能合理地解释了毒力差异，但另一种假说认为，该物种的致病潜力可能取决于发炎肠道中生态系统条件的改变。一个潜在的差异是氧气的可用性，在炎症条件下通常会增加，并且已知会调节细菌的毒力。因此，我们假设氧气会影响弯曲菌属（Campylobacter concisus）的生理学。因此，我们研究了微需氧或厌氧环境对弯曲菌属（Campylobacter concisus）运动和生物膜形成的影响，这是宿主定植和传播的两个重要决定因素。本研究使用了来自 IBD（n = 23）、肠胃炎（n = 8）和健康受试者（n = 13）的唾液、肠道黏膜活检和粪便中分离的弯曲菌属（Campylobacter concisus）分离株（n = 46）。使用结晶紫测定法测定生物膜形成能力，而通过软琼脂评估分散度则允许评估运动能力。GI 疾病与运动或生物膜形成能力之间没有关联。口腔分离株与粪便分离株相比，生物膜形成能力显著更高（p<0.03），并且运动和生物膜形成之间存在强烈的负相关（r = -0.7；p = 0.01）。与厌氧条件相比，在微需氧条件下培养时，菌株的运动能力显著增加（p<0.001）。在微需氧条件下，一部分分离株的生物膜形成也增加了。因此，氧气可用性的差异似乎会影响机会性胃肠道病原体弯曲菌属（Campylobacter concisus）的关键生理方面。
