Importance of Ompw gene to diagnose Vibrio cholerae isolated from stool and water samples

Background. Cholera is a severe acute watery diarrheal disease caused by O1 and O139 serogroup of Vibrio cholerae. The outer-membrane protein W (OmpW) a virulence factor, is involved in inducing protective immunity and triggering the immune response. The aim of this study is to find a rapid and accurate method for diagnosing Vibrio cholerae and investigate the possibility of OmpW gene to achieve this goal, and identify the effective antibiotic against this bacteria. Methods. The current study included 400 stool samples from patients who were suspected of having cholera and 50 samples of water have been collected from various water liquefaction stations in Thi-Qar province. The samples were examined by routine and advanced biochemical, serological methods and molecular method by using PCR to amplify 16S rDNA gene and gene OmpW. Results. Results of stool samples revealed that only 41 (10.25%) of the isolates were identified as Vibrio cholerae by biochemical methods while 38 (92.68%) of the isolates were diagnosed as Ogawa serotype of Vibrio cholerae serogroup O1 by serological and molecular methods. While the water samples did not reveal the appearance of Vibrio cholerae by molecular diagnosis. The study revealed a difference in the resistence rates of isolates to some antibiotics, with the highest percentage rate of resistance (100%) to trimethoprim-sulfamethoxazole while lowest percentage rate of resistance (5.26%) to piperacillin-tazobactam. Also, the study noted 56.58% of isolated V. cholera were resistant for tested antibiotics, 24.73% of isolated V. cholera were gave intermediate response, while 18.69% were sensitive for tested antibiotics. Conclusion. All identified isolates were registered in GenBank, two isolates with number LC793854 and LC793858 were recorded as new isolates. OmpW gene showed great accuracy to diagnose Vibrio cholerae, no less important than the accuracy of 16S rDNA gene to diagnose of these bacteria, and Piperacillin-tazobactam is the best antibiotic to treatment of cholera.