Investigation of campylobacter species other than C. jejuni and C. coli in acute gastroenteritis

Campylobacter infections are the most commonly detected food-borne bacterial infections in Europe and America. Although C. jejuni and C. coli are responsible for 95% of Campylobacter infections, reports of non-jejuni/coli Campylobacter species have been increasing recently. In this study, it was aimed to isolate Campylobacter species other than C. jejuni/coli by different conventional culture methods and also identify the strains by biochemical and molecular methods. In this study, fecal samples of 500 patients admitted to the hospital with acute gastroenteritis between December 2016 -January 2018 and those of 100 healthy individuals were evaluated for the presence of Campylobacter spp. by culture method both using a selective medium and membrane filter method. Bacteria were identified to genus level by conventional methods and PCR and to species level by multiplex PCR. In our study 31 (6.2%) Campylobacter spp. were isolated all from ill individuals. Of these bacteria, 21 (67.8%) were C. jejuni, 9 (29%) were C. coli and one (3.2%) as C. concisus. C. jejuni strains gave positive result by hippurate hydrolysis test whereas C. coli strains gave negative. However, the strain which was determined to be C. consicus by mPCR gave false positive result. This finding was confirmed by PCR method specific for hippuricase (hipO) gene. In generally, the use of molecular methods for identification of Campylobacter at species level was found to be more reliable. The patient infected by with C. concisus developed acute bloody diarrhea with abdominal pain and vomiting that ended in seven days. Microscopical analysis of the stool revealed polymorphonuclear leukocytes and Salmonella, Shigella, Aeromonas, Yersinia and Vibrio were negative in the culture. C. concisus strain was thought to be associated with diarrhea. The study was the first study carried out among humans in which Campylobacter species other than C. jejuni/C.coli were investigated and C. concisus was isolated.