OralCampylobacterspecies: Initiators of a subgroup of inflammatory bowel disease?

Abstract

In recent years, a number of studies detected a significantly higher prevalence of Campylobacter species such as Campylobacter concisus (C. concisus) in intestinal biopsies and fecal samples collected from patients with inflammatory bowel disease (IBD) compared to controls. Most of these Campylobacter species are not of zoonotic origin but are human oral Campylobacter species. Bacterial species usually cause diseases in the location where they colonize. However, C. concisus and other oral Campylobacter species are associated with IBD occurring at the lower parts of the gastrointestinal tract, suggesting that these Campylobacter species may have unique virulence factors that are expressed in the lower parts of the gastrointestinal tract.

Genome analysis of Campylobacter concisus strains from patients with inflammatory bowel disease and gastroenteritis provides new insights into pathogenicity

“…The core-genome, the sequences of six housekeeping genes and the 23S rRNA gene consistently assigned these C. concisus strains into two genomospecies (Figs 1, 2, 3). The enteric strains did not form distinct groups within both genomospecies, further supporting our previous theory that some oral C. concisus strains may cause enteric disease when colonizing the intestinal tract33132. The previous study examining eight C. concisus strains reported that 16S rRNA gene of C. concisus strains was able to differentiate C. concisus strains isolated from patients with CD and gastroenteritis, this was not observed in our study where 36 C. concisus strains were examined (Fig.…”

Clinical relevance of infections with zoonotic and human oral species of Campylobacter

“…Bacteria generally cause a disease where they colonize, but C. concisus is unusual in that the colonization site of C. concisus is normally the oral cavity, but the species is associated with gastrointestinal diseases like IBD. C. concisus is capable of colonizing the intestine, possibly by producing unique virulence factors only expressed in the intestinal environment (Zhang, 2015). Although related pathogenesis mechanism is unclear yet, these results indicate that C. concisus may be related to initiation of IBD.…”

“…Although the cause of IBD is poorly understood, it is assumed that IBD occurs in humans because of a genetic predisposition and is triggered by an environmental factor (Sartor, 2006). In a review by Zhang (2015), a number of studies are cited that reported that Campylobacter spp. was detected at significantly higher prevalence in intestinal samples from IBD patients.…”

“…This method could not reveal whether C. concisus is related to IBD. C. concisus is also isolated from dental samples and normally colonizes the human oral cavity, but it is not clear whether it colonizes the intestinal tract (Zhang et al, , 2015. In a study by Zhang et al (2009), they found that prevalence of C. concisus is higher among IBD patients (51%) than controls (2%) according to an identification method based on C. concisus-specific IgG antibody levels in addition to successfully isolated viable bacteria from an intestinal biopsy of IBD patients.…”

“…The presence of H2 gas allows C. concisus to grow regardless of whether the conditions are microaerobic and anaerobic. Thus, in individuals whose intestinal environment has an ability to provide H2, C. concisus is likely to colonize the intestine and use H 2 during the growth (Zhang, 2015). Bacteria generally cause a disease where they colonize, but C. concisus is unusual in that the colonization site of C. concisus is normally the oral cavity, but the species is associated with gastrointestinal diseases like IBD.…”