Determination of phylogenetic relationship among Vibrio parahaemolyticus isolates from Persian gulf and the evaluation of their susecptibilty to antibiotics

Vibrio parahaemolyticus is a pathogenic vibrio that exists in the sea coast worldwide. This bacterium causes diarrhea because of consumption of raw sea foods. The purpose of the present study was the determination of phylogenetic relationship among Vibrio parahaemolyticus isolates from Persian gulf and evaluation of their susecptibility to antibiotics.
A total 89 water, sediment, fish and shrimp samples were collected from different regions of the Persian Gulf and evaluated for isolation and identification (phenotypic and molecular (16SrRNA)) of Vibrio parahaemolyticus . Then Kanagawa positive and negative Vibrio parahaemolyticus isolates were separated and the phylogenetic relationship among the isolates and two standard genes were determined. Finally, susceptibility of Kanagawa positive Vibrio parahaemolyticus to antibiotics and Minimal inhibitory concentrations were assessed by disk diffusion and double serial dilution methods.
A total nine Vibrio parahaemolyticus were isolated and identified from the samples. Of all five strains were Kanagawa positive and 4 strains were Kanagawa negative. All isolates exhibited phylogenetic relationship to each other except NSP1 strain. The results obtained from antibiotic susceptibility illustrated that Kanagawa positive Vibrio parahaemolyticus were resistance to Vancomycin, Oxacillin, and Amikacin and susceptible to Trimetoprim Sulfometaxazole. The lowest Minimal inhibitory Concentration (MIC) value was found for Sulfometaxazole and highest MIC value was found for Nitofuran.
The present study illustrated that pathogenic and nonpathogenic Vibrio parahaemolyticus of Persian Gulf have phylogenetic relationship. Hence, horizontal gene transfer occurs among them. In addition, Trimetoprim Sulfometaxazole might be consided a durg of choice for treatment of the patient suffering from Vibrio parahaemolyticus infections.