Fig. 1
From: Pandemics, pathogenicity and changing molecular epidemiology of cholera in the era of global warming
Classification of Vibrio cholera. V. cholerae is classified firstly by serotype. O1 is subdivided into two biotypes, classic and El Tor on the basis of phenotypic characteristics (although genetic hybrids between the V. cholerae O1 classic and El Tor biotypes have been reported). Organisms in both biotypes are further classified according to the presence of somatic antigens into two major serotypes (Inaba and Ogawa) and an unstable intermediate type (Hikojima)