Emerging dynamics of human campylobacteriosis in Southern Ireland

Infections with Campylobacter spp. pose a significant health burden worldwide. The significance of Campylobacter jejuni/Campylobacter coli infection is well appreciated but the contribution of non-C. jejuni/C. coli spp. to human gastroenteritis is largely unknown. In this study, we employed a two-tiered molecular study on 7194 patient faecal samples received by the Microbiology Department in Cork University Hospital during 2009. The first step, using EntericBio® (Serosep), a multiplex PCR system, detected Campylobacter to the genus level. The second step, utilizing Campylobacter species-specific PCR identified to the species level. A total of 340 samples were confirmed as Campylobacter genus positive, 329 of which were identified to species level with 33 samples containing mixed Campylobacter infections. Campylobacter jejuni, present in 72.4% of samples, was the most common species detected, however, 27.4% of patient samples contained non-C. jejuni/C. coli spp.; Campylobacter fetus (2.4%), Campylobacter upsaliensis (1.2%), Campylobacter hyointestinalis (1.5%), Campylobacter lari (0.6%) and an emerging species, Campylobacter ureolyticus (24.4%). We report a prominent seasonal distribution for campylobacteriosis (Spring), with C. ureolyticus (March) preceeding slightly C. jejuni/C. coli (April/May).