Isolation rate of Campylobacter spp. and detection of virulence genes of Campylobacter jejuni across the broiler chain

Abstract

The aim of the study was to identify the isolation rate of thermotolerant campylobacters in a small-scale broiler-meat production farm over a one-year period. The second deliverable of the study was to determine the potential virulence markers. The laboratory investigation was performed on 283 samples (cloacal swabs, caeca, carcass swabs) collected on three sampling points (farm, slaughter line, and cold storage). The isolates obtained with the conventional microbiological method were confirmed with multiplex PCR for identification of campylobacters. The presence of 10 virulence genes was analyzed in the C. jejuni isolates ( flaA, racR, virB11, dnaJ, wlaN, cadF, ciaB, cdtA, cdtB, cdtC). Out of 283 samples, 169 (59.7%) were confirmed as Campylobacter spp., 111 (39.2%) C. jejuni, and 43 (15.2%) C. coli. C. jejuni was the most prevalent in all sampling points. Campylobacter spp. showed a characteristically seasonal prevalence with the highest isolation rate during the warmer period of the year. We detected the cadF and ciaB genes in all C. jejuni isolates. The flaA gene was present in 50% of the examined strains. The cdt genes (cdtA, cdtB, and cdtC) were confirmed in 52.8%, 52.8%, and 47.2% of the C. jejuni strains, respectively. C. jejuni showed 15 profiles of virulence patterns with four predominant profiles.

Keywords

• isolation rate
• campylobacter spp.
• virulence
• campylobacter jejuni
• broiler chain