title: Campylobacter concisus pathotypes are present at significant levels in patients with gastroenteritis.
abstract: Given that Campylobacter jejuni is recognized as the most common cause of bacterial gastroenteritis worldwide, recent findings showing comparable levels of Campylobacter concisus in patients with gastroenteritis would suggest that this bacterium is clinically important. The prevalence and abundance of Campylobacter concisus in stool samples collected from patients with acute gastroenteritis was examined using quantitative real-time PCR. The associated virulence determinants exotoxin 9 and zonula occludens toxin DNA were detected for Campylobacter concisus-infected samples using real-time PCR. Campylobacter concisus was detected at high prevalence in patients with gastroenteritis (49.7 %), higher than that observed for Campylobacter jejuni (∼5 %). The levels of Campylobacter concisus were putatively classified into clinically relevant and potentially transient subgroups based on a threshold developed using Campylobacter jejuni levels, as the highly sensitive real-time PCR probably detected transient passage of the bacterium from the oral cavity. A total of 18 % of patients were found to have clinically relevant levels of Campylobacter concisus, a significant number of which also had high levels of one of the virulence determinants. Of these patients, 78 % were found to have no other gastrointestinal pathogen identified in the stool, which strongly suggests a role for Campylobacter concisus in the aetiology of gastroenteritis in these patients. These results emphasize the need for diagnostic laboratories to employ identification protocols for emerging Campylobacter species. Clinical follow-up in patients presenting with high levels of Campylobacter concisus in the intestinal tract is needed, given that it has been associated with more chronic sequelae.
authors.affiliation: School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney 2052, NSW, Australia.
authors.forename: Alexander P
authors.initials: AP
authors.lastname: Underwood
authors.affiliation: School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney 2052, NSW, Australia.
authors.forename: Nadeem O
authors.initials: NO
authors.lastname: Kaakoush
authors.affiliation: School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney 2052, NSW, Australia.
authors.forename: Nidhi
authors.initials: N
authors.lastname: Sodhi
authors.affiliation: Virology Division, Department of Microbiology, SEALS, Prince of Wales Hospital, Randwick, NSW, Australia.
authors.forename: Juan
authors.initials: J
authors.lastname: Merif
authors.affiliation: Department of Paediatrics, University Malaya Medical Centre, Kuala Lumpur, Malaysia.
authors.forename: Way
authors.initials: W
authors.lastname: Seah Lee
authors.affiliation: Gastrointestinal and Liver Unit, The Prince of Wales Hospital, Randwick, NSW 2031, Australia.
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Riordan
authors.affiliation: School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney 2052, NSW, Australia.|Virology Division, Department of Microbiology, SEALS, Prince of Wales Hospital, Randwick, NSW, Australia.
authors.forename: William D
authors.initials: WD
authors.lastname: Rawlinson
authors.affiliation: School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney 2052, NSW, Australia.
authors.forename: Hazel M
authors.initials: HM
authors.lastname: Mitchell
mesh_terms: D000293:Adolescent; D000328:Adult; D002167:Campylobacter / Q000145:classification* / Q000472:pathogenicity*; D002169:Campylobacter Infections / Q000382:microbiology*; D002648:Child; D002675:Child, Preschool; D003967:Diarrhea / Q000382:microbiology; D005243:Feces / Q000382:microbiology; D005260:Female; D005759:Gastroenteritis / Q000382:microbiology*; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D014774:Virulence; D055815:Young Adult