The acute diarrheal disease cholera remains a significant public health problem, due to its ability to spread rapidly and kill a high proportion of those affected. Vibrio cholerae, the etiologic agent of cholera, is a highly motile non-invasive Gram-negative bacterium which colonizes the small intestine and produces and secretes a potent enterotoxin called cholera toxin (CT), the major virulence determinant primarily responsible for the disease cholera