Myanmar Health Sciences Research Journal
Volume 27, Number 3
TITLE: Genotypic Characteristics of Vibrio cholerae Strains from Myanmar: Comparison between Past and Recent Isolates
AUTHOR: Wah Wah Aung, Kazuhisa Okada, Mar Mar Nyein, Mya Mya Aye, Nan Aye Thidar Oo, Toe Sandar, Mathukorn Na-Ubol, Wirongrong Natakuathung & Shigeyuki Hamada
SOURCE: Myanmar Health Sciences Research Journal. 2015; 27(3): 163-168
ABSTRACT: Atypical E1 Tor Vibrio cholerae, which possesses traits of both classical and E1 Tor biotypes, has replaced the seventh pandemic E1 Tor V. cholerae O1 in Asian and African countries. The origin and spread of these E1 Tor V. cholerae in Myanmar should be tracked by genomic analysis. The genotypic characteristic of recent (2012) and past (1982-1996) clinical V. cholerae O1 isolates from Yangon, Myanmar were investigated. V. cholerae isolates were confirmed by culture, biochemical identification, serotyping and polymerase chain reaction. Eight V. cholerae strains isolated during 1982-1996 and 34 strains isolated in 2012 were undergone genotypic analysis by Pulse Field Gel Electrophoresis Typing (PFGE) and Multilocus Variable Number Tamdem Repeat Analysis DNA sequencing. Recent 2012 isolates were atypical E1 Tor, which carried the classical cholera toxin B subunit gene (ctxBCla) and E1 Tor repressor gene (rstRE1) and exhibited a total of 10 PFGE patterns. Among V. cholerae O1 strains isolated during 1982-1996, 4 pulsotypes were identified and they were different from 2012 PFGE patterns. Pulsotype Y1 and Y4 isolates carried ctxBEl and rstRE1 and they are related to seventh cholera pandemic E1 Tor strains. Pulsotype Y2 isolate was atypical E1 Tor which carried ctxBCla and rstRE1. Remarkably,seventh cholera pandemic prototype E1 Tor was observed only in 1982 isolates and atypical E1 Tor with ctxBCla and rstRE1 was found to be existed in Yangon 30 years ago. This study provided basic genetic information on past and recent cholera strains in Myanmar.
SUBJECT HEADINGS: Vibrio cholerae, Genotypic characteristics, Myanmar