Recent advances in cholera genetics

Vibrio cholerae is a comprehensively studied human pathogen. Genetic analyses conducted in the recent past show that the pathogenic forms of the microbe share certain virulence traits that distinguish epidemic strains from non-epidemic forms. The microbe has a dual lifestyle, primarily residing in the aquatic environs in association with zooplankton and other flora, but is also capable of transiently residing in the human intestine with the toxigenic forms causing cholera. The presence of virulence-associated genes in environmental strains provides interesting avenues to understand the pathogenicity of the disease; this is especially so because rampant genetic exchange has been demonstrated as the primary cause for the origination of new epidemic forms in many instances. Cholera research took a new turn with the completion of the sequencing of the whole genome of an El Tor biotype strain, opening new vistas to probe into the deepest pathogenic secrets of the organism. This review attempts to bring together some of the most important researches in recent times that have gone into understanding the genetics of the cholera germ