LTA and vibrio infectious disease: Some research studies have shown that heat-labile toxin (LT) secreted by Enterotoxigenic Escherichia coli (ETEC) and Vibrio cholerae, as well as cholera enterotoxin (CT) secreted by Vibrio cholerae, stimulate adenylate cyclase, resulting in an increase in the cAMP level and the activation of cAMP-dependent protein kinase A (PKA), ultimately leading to the phosphorylation of CFTR channels (Sears and Kaper, 1996; Vaandrager et al., 1997; Hug et al., 2003).