The susceptibility of Campylobacter concisus to the bactericidal effects of normal human serum. Issue 3 (28th January 2015)

• Record Type: Journal Article
• Authors: Kirk, Karina Frahm; Nielsen, Hans Linde; Nielsen, Henrik
• Is Part Of: Apmis. Volume 123:Issue 3(2015:Mar.)
• Page Start: 269
• Page End: 274
• Publication Date: 2015-01-28
• Subjects: Pathology -- Periodicals; Microbiology -- Periodicals; Immunology -- Periodicals; 572
• DOI: 10.1111/apm.12346
• Languages: English
• ISSNs: 0903-4641

Abstract

<abstract abstract-type="main" id="apm12346-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p> <italic>Campylobacter concisus</italic> is an emerging pathogen of the gastrointestinal tract that has been associated with Barrett's oesophagus, enteritis and inflammatory bowel disease. Despite having invasive potential in intestinal epithelial cells <italic>in‐vitro, </italic> bacteraemic cases with <italic>C. concisus</italic> are extremely scarce, having only been reported once. Therefore, we conducted a serum resistance assay to investigate the bactericidal effects of human complement on <italic>C. concisus</italic> in comparison to some other <italic>Campylobacter</italic> species. In total, 22 <italic>Campylobacter</italic> strains were tested by incubation with normal human serum and subsequent cultivation in microaerobic conditions for 48 hours. Killing time was evaluated by decrease in total CFU over time for incubation with different serum concentrations. Faecal isolates of <italic>C. concisus</italic> showed inoculum reduction to less than 50% after 30 min. <italic>Campylobacter jejuni</italic> was sensitive to serum, but killing was delayed and a bacteraemic <italic>Campylobacter fetus</italic> subsp. <italic>fetus</italic> isolate was completely serum resistant. Interestingly, sensitivity of enteric <italic>C. concisus</italic> to human serum was not associated to different faecal‐calprotectin levels. We find that faecal isolates of <italic>C. concisus</italic> are sensitive to the bactericidal effects of serum, which may explain why <italic>C. concisus</italic> is not associated to bacteraemia.</p> </abstract>