Molecular epidemiologic characterization of vibrio cholerae isolates in Guangxi,1997～2001

Objective To describe the molecular and epidemiologic features of the Vibrio cholerae strains in Guangxi from 1997 to 2001 and to explore their interrelation.Methods Blotting was used to detect genes ctxAB and zot,which were associated with the toxigenicity of Vibrio choleraeLabeled 16s rRNA,as a probe,was used for ribotype characterization of the organisms.Results Gene ctxAB and zot were found in all of the Vibrio cholerae O_ 139 strains tested;while ctxAB and zot were present in 97.67% and 95.35% of El Tor biotype strains,respectively.Six different ribotypes(RT_1-RT_6),mainly ribotypes 1 and 4,were identified.Conclusion The presence of ctxAB and zot among the overwhelming majority of tested isolates indicates the prevalence of highly toxigenic Vibrio cholerae strains in Guangxi.The ribotype profiles exhibits significant differences between strains isolated during 1997 to 2000 and those in 2001.Strains of the same ribotypes could originate from different serotypes and phage-biotypes.This study suggests the Inaba strains in 2001 have evolved from new clones and not be an extension of those in 2001.