title: Molecular evolution and functional divergence of Vibrio cholerae.
abstract: The purpose of this review is to synopsize and highlight the recent subtle genetic changes in cholera causing toxigenic Vibrio cholerae with special reference to their virulence, integrating and conjugative elements and toxin-antitoxin systems. It is not intended to cover issues on the whole genome sequence and epidemiology of cholera.
  
  
  
  Analyses have been made using major published works on genetic changes associated with potential virulence, integrating and conjugative elements and toxin-antitoxin systems of toxigenic V. cholerae. During the course of evolution, V. cholerae strains show evidence of genetic selection for the expression of additional virulence, better survival in the environment, colonization ability and antimicrobial resistance. Some of the critical modifications that occurred at the molecular level include CTXϕ genome, cholera toxin B-subunit, integrating and conjugative elements and toxin-antitoxin systems. Frequent changes in the genome of V. cholerae appear to be an ongoing dynamic process that is assisting the pathogen to subtly change during or after epidemics of cholera.
  
  
  
  Cholera is a reemerging public health problem. Continued basic research is important to understand the changing dynamics of bacterial virulence, survival strategies and disease pathogenesis for efficient therapeutic intervention and to abort transmission of the disease.
authors.affiliation: aTranslational Health Science and Technology Institute, Faridabad bNational Institute of Pharmaceutical Education and Research cNational Institute of Cholera and Enteric Diseases, Kolkata, West Bengal dSouth East Asia Regional Office, World Health Organization, New Delhi, India.
authors.forename: Bhabatosh
authors.initials: B
authors.lastname: Das
authors.forename: Gururaja P
authors.initials: GP
authors.lastname: Pazhani
authors.forename: Anirban
authors.initials: A
authors.lastname: Sarkar
authors.forename: Asish K
authors.initials: AK
authors.lastname: Mukhopadhyay
authors.forename: G Balakrish
authors.initials: GB
authors.lastname: Nair
authors.forename: Thandavarayan
authors.initials: T
authors.lastname: Ramamurthy
mesh_terms: D002771:Cholera / Q000382:microbiology*; D002772:Cholera Toxin; D004196:Disease Outbreaks; D019143:Evolution, Molecular; D016680:Genome, Bacterial; D006801:Humans; D014734:Vibrio cholerae / Q000235:genetics* / Q000472:pathogenicity* / Q000502:physiology
chemical_list: D002772:Cholera Toxin