Variation of toxigenic Vibrio cholerae O1 in the aquatic environment of Bangladesh and its correlation with the clinical strains.

The diversity of toxigenic V. cholerae O1 in the aquatic environment of Bangladesh is not known. A total of 18 environmental and 18 clinical strains of toxigenic V. cholerae O1 were isolated simultaneously from four different geographical areas and tested for variation by the pulsed-field gel electrophoresis method. Environmental strains showed diversified profiles and one of the profiles was common to some environmental strains and most clinical strains. It appears that one clone has an advantage over others to cause disease. These findings suggest that the study of the molecular ecology of V. cholerae O1 in relation to its environmental reservoir is important in identifying virulent strains that cause disease.