Comparative genomics of epidemic strains from cholera patients revealed evolution of Vibrio cholerae O1


Cholera is an acute serious diarrheal disease caused by a bacterial pathogen Vibrio cholerae O1, and this infectious disease is a major public health problem in many developing countries. The Bengal region including Kolkata City is considered the epicenter for the cholera pandemic. Therefore, for control and prevention, it is important to understand the genetic dynamism of the strains from cholera patients in Kolkata, India.

By collaborating with other institutions including the National Institute of Infectious Diseases, Dr. Shin-ichi Miyoshi obtained and analyzed the whole genome sequence data of 80 strains isolated between 2007 and 2014 in Kolkata. His research group also carried out the study on the periodical variation of the heterogeneous genomic region termed the Vibrio seventh pandemic island (VSP)-II.

The results of the comparative genomic analysis revealed the heterogeneity of VSP-II in Kolkata strains. Namely, they found the continuous mutation of the VSP-II and the resulting shift of the predominant strain to a virulent strain in 2010. These findings demonstrate that the epidemic of cholera in Kolkata was caused by several distinct strains that have been constantly changing within the genetic lineages of V. cholerae O1 in recent years.

Daisuke Imamura, Masatomo Morita, Tsuyoshi Sekizuka, Tamaki Mizuno, Taichiro Takemura, Tetsu Yamashiro, Goutam Chowdhury, Gururaja P. Pazhani, Asish K. Mukhopadhyay, Thandavarayan Ramamurthy, Shin-ichi Miyoshi, Makoto Kuroda, Sumio Shinoda, and Makoto Ohnishi.

Title of original paper
Comparative genome analysis of VSP-II and SNPs reveals heterogenic variation in contemporary strains of Vibrio cholerae O1 isolated from cholera patients in Kolkata, India.

Journal, volume, pages and year
PLoS Negl Trop Dis 11,e0005386 (2017).

Digital Object Identifier (DOI)

Journal website

Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University.

Graduate School website

Genetic variation of VSP-II in V. cholerae O1 Kolkata strains.