Molecular typing and virulence gene profiles of Campylobacter jejuni isolated from human, animals, and meat in northern Iran

Campylobacter jejuni is one of the most important agents in gastrointestinal infections both in developed and developing countries. Determining the source of the human infections and the relationship of virulence gene properties and origin of the isolates are necessary epidemiologic data to control the infection in an area. We conducted a present study to genotype C. jejuni isolates recovered from human, broiler, cattle, poultry meat, and cattle meat in Mazandaran province, north of Iran. For this purpose, 100 isolates of C. jejuni (20 isolates from each source), which had been previously isolated, were subjected to Random Amplification of Polymorphic DNA Polymerase Chain Reaction (RAPD-PCR), 16S rRNA Restriction Fragment Length Polymorphism (RFLP) analysis and six virulence genes (cdtA, cdtB, cdtC, cadF, iamA and pldA) pattern. In total, 98 isolates were typed using RAPD-PCR and 32 different genotypic patterns were observed. All 100 isolates showed similar enzymatic digestion pattern in 16S rRNA-RFLP technique by using DdeI and AluI enzymes. The cadF gene showed a 100% presence among the isolates. The prevalence of cdtA, cdtB, cdtC, pldA, and iamA genes was 97%, 97%, 96%, 72% and 60%, respectively. Ten different genotypic patterns (VP1-VP10) were identified from the presence of six virulence genes. According to the results, 16S rRNA-RFLP cannot type the isolates, but both RAPD and virulence typing methods showed significant relationships between some of the genotypes and a specific source. A potential role of poultry isolates in human infections was observed using these two methods. RAPD technique had the best results for typing of the Campylobacter isolates between these three methods.