Humans Surviving Cholera Develop Antibodies against Vibrio choleraeO-Specific Polysaccharide That Inhibit Pathogen Motility

Cholera is a severe dehydrating illness of humans caused by Vibrio cholerae. V. choleraeis a highly motile bacterium that has a single flagellum covered in lipopolysaccharide (LPS) displaying O-specific polysaccharide (OSP), and V. choleraemotility correlates with its ability to cause disease. The mechanisms of protection against cholera are not well understood; however, since V. choleraeis a noninvasive intestinal pathogen, it is likely that antibodies that bind the pathogen or its products in the intestinal lumen contribute to protection from infection. Here, we demonstrate that OSP-specific antibodies isolated from humans surviving cholera in Bangladesh inhibit V. choleraemotility and are associated with protection against challenge in a motility-dependent manner.