Vibrio cholerae

Abstract

"Vibrio cholerae O1 serogroup El Tor biotype strains are the cause of the current seventh cholera pandemic starting in 1961 and have gradually replaced the classical biotype strains that caused the sixth cholera pandemic. At the time the O139 serogroup strains emerged, there was a cryptic but important change in El Tor biotype strains. First appearing in 1991, atypical strains harboring the classical cholera toxin gene have entirely replaced the prototype El Tor strains producing El Tor type toxin, similar to the prototype El Tor biotype strains replacing the classical biotype strains 30 years before. The atypical El Tor biotype strains now should be considered typical El Tor strains since they have prevailed globally. In this chapter, genetic changes in the CTX phage, which is a filamentous phage that can lysogenize the V. cholerae genome, and the genome of the V. cholerae O1 El Tor biotype strains of the seventh cholera pandemic are presented. ? 2014 by John Wiley & Sons, Ltd. All rights reserved.