Occurrence of virulence genes and strain diversity of thermophilic campylobacters isolated from cattle and sheep faecal samples

The objective of this study was to investigate the genotypic characteristics of Campylobacter isolates in Shiraz, Iran. A total of 40 Campylobacter isolates including 20 C. jejuni and 20 C. coli were recovered from both cattle and sheep faeces by cultivation methods. The isolates were identified on the basis of polymerase chain reaction (PCR) detection of 16SrRNA and multiplex PCR to determine two species. For confirmed isolates, PCR was carried out for the presence of virulence genes using specific primers. Other than verifying the genetic diversity of thermophilic Campylobacter isolates, flaA PCR-RFLP was performed. Results showed the high prevalence (100%) of the cadF gene and three genes associated with cytolethal distending toxin (CDT). Plasmid virB11 gene was not found in any Campylobacter isolate, and dissimilarities and discrepancies occurred in pldA, iamA, wlaN, waaC and cgtB genes. Among the 40 Campylobacter isolates studied, nine different types were defined by flaA-typing. Results indicated genetic diversity among Campylobacter isolates recovered from cattle and sheep faecal samples. Findings showed the potential ability of C. jejuni and C. coli with cattle and sheep origins to cause infection in humans.