Detection of toxigenic Vibrio cholerae by PCR

Tholera toxin (CT) is a major virulence factor of V. cholerae causing water diarrhea. The detection of CT-producing V. cholerae using conventional culture-, biochemical- and immunological-based assays is time-consuming, laborious, and requiring more than three days perform. In this work a specific primers for ctxB gene were used for detection of V. cholera in water samples. Few colonies of V. cholera were suspended in water and used as a template in PCR reaction for the detection of ctxB gene. The 391-bp sequence of a gene that codes for the cholera toxin B subunit was amplified by PCR. Direct use of V. cholerae pure culture for PCR replaces the need for DNA extraction or boiling. Increase the concentration of MgCl2 enhances the efficiency of amplification. The specificity of the assay was determined to be specific for V. cholerae but not for, vibrio related bacteria, E. coli, Non- Agglutinable (NAG) V. cholerae, and Aeromonas sp.