Comparative analysis of clinical and environmental Vibrio cholerae strains isolated in Vietnam

In Vietnam, from 1979-1996, there were 56050 infectious cholera cases and 1272 deaths reported nationally. In 2006-2010, the reported cases were 3646. Since 2010, no new cholera cases have been reported in Vietnam, largely due to the effectiveness of the oral cholera vaccine campaign implemented through the National Expanded Programme on Immunization which was rolled out from 1992. However, V. cholerae non 01, and non 139 was still isolated from the environment post 2010. In order to prevent future outbreaks, it is important to understand the relationship between these environmental isolates and representative clinical isolates from previous outbreaks. Thus our aims in this study were; to compare the genomic structure of clinical and environmental strains isolated in Hanoi; to investigate the presence and roles of TSS6 and TCP systems, and ctxA in environmental isolates; and lastly to suggest biomarkers which can be used to classify pathogenic and nonpathogenic V. cholerae strains.