Pulsed-field gel electrophoresis fingerprinting of Campylobacter jejuni and Campylobacter coli strains isolated from clinical specimens, Iran.

The aim of this study was to determine the clonal correlation of Campylobacter strains isolated from diarrheal children under 5 years of age in Iran using the PFGE method and to determine the antimicrobial susceptibility and virulence gene content of strains. Of 750 patients with bacterial diarrhea, 33 (4%) Campylobacter spp., including 31 C. jejuni (94%) and 2 C. coli (6%), were isolated during 18-month period in Tehran, Iran. Except for one strain, remaining Campylobacter strains were positive for the flaA gene. A complete set of cytolethal distending toxin (CDT) encoding genes (cdtABC) were detected in 52% of the C. jejuni strains, while the 2 C. coli isolates under study only harbored cdtA and cdtB of the CDT cluster. All strains were resistant to at least three antibiotic classes. Resistance to ampicillin among C. coli and C. jejuni strains was 100% and 84%, respectively, and 80% of all strains were susceptible to gentamicin. PFGE genotyping generated 19 pulsotypes with two major clusters, displaying the maximum and minimum similarity of 100% and 26%, respectively. The C. coli strains showed clearly distinct pulsotypes and each fell within separate clusters. A very homogeneous Campylobacter population was detected among Iranian patients with 33 % of strains showing identical banding patterns and no clear correlation was observed between antibiotic resistance profiles and PFGE patterns of the isolates.