Characterization of Campylobacter jejuni isolates from dairy cattle farms in Korea

Abstract

Campylobacter jejuni is a major foodborne pathogen that is being increasingly identified in various countries worldwide. In this study, 298 samples from 15 dairy cattle farms in Korea were collected between August 2012 and September 2013 in order to measure the prevalence of C. jejuni. These cattle isolates, together with C. jejuni from other sources (chicken, human, and duck), were characterized based on virulence and survival gene profiles, pulsed-field gel electrophoresis (PFGE) analysis, and flaA typing. A total of 71 C. jejuni strains were isolated from the 298 samples, and C. jejuni was found to be prevalent in 9 of the 15 cattle farms. HtrA was expressed in all 111 isolates tested, whereas 4 other genes (flhB, cdtB, perR, crsA) were present in most isolates

by contrast, virB11 and hcp were detected in 12 (10.8%) and 54 (48.6%) of the 111 isolates, respectively. Based on a 90%-similarity criterion, 46 PFGE patterns, 39 flaApatterns, and 60 composite patterns were detected from the PFGE analysis and flaA typing results. The discriminatory indices for PFGE, flaA typing, and composite results were 0.9584, 0.9445, and 0.9766, respectively. Similar band patterns were observed between cattle farms and between cattle, chicken, and human isolates. In conclusion, diverse C. jejuni genotypes were identified in cattle farms in Korea, and the tested isolates possessed virulence and survival-factor genes that might present a risk for human campylobacteriosis. Therefore, strict hygiene measures must be developed in cattle farms in order to reduce the threat of human campylobacteriosis to the public.