Genetic diversities in atypical El Tor strains from Vibrio cholerae O1 serogroup in Fujian Province, China
10.3969/cjz.j.issn.1002-2694.2014.08.003
- VernacularTitle:福建省非典型 O1群埃尔托型霍乱弧菌的研究
- Author:
Aiping CHEN
;
Enhui ZHENG
;
Quwen LI
;
Haibin XU
;
Jinsong YANG
;
Linglan WANG
;
Jinfeng ZHENG
;
Yansheng YAN
- Publication Type:Journal Article
- Keywords:
V ibrio cholerae;
virulence gene;
PCR;
allele;
sequence analysis
- From:
Chinese Journal of Zoonoses
2014;(8):787-792
- CountryChina
- Language:Chinese
-
Abstract:
The emergence of atypical El Tor strains from V .cholerae in South Asia and Africa has been attributed to several outbreaks in recent decades ,however ,backgrounds of such strains in China remain exclusive .In this study ,PCR am-plification of both El Tor and classical alleles for ctxB ,tcpA ,rstR and hlyA genes was attempted in sixty-nine El Tor isolates from Fujian between 1962 to 2005 ,in addition ,some amplicons were sequence-analyzed .Thus ,the time point of atypical EVC strains in Fujian was determined ,genetic diversities of such strains were investigated .It was revealed that ctxB-Cl ,tcpA-Cl and hlyA genes were detected in O1 serogroup EVC isolates from Fujian since 1962 .Although rstR-Cl gene was solely detected in isolates between 1994 to 2000 .It was indicated by sequence analysis that atypical EVC strains from Fujian possessed a novel T→G mutation at residual 204 of the ctxB gene .Remarkably ,two novel ctxB genotypes (ctxB-10 and ctxB-11) were identified in one strain .The residual 115-C of ctxB in ctxB-11 showed characteristics of ctxB-Cl ,however ,its residual 203-T demonstra-ted characteristics of ctxB-El .This observation implied that it was common in O1 serogroup EVC strains from Fujian hybrid-ized with classical alleles since 1962 ,which would be the earliest time-point for the emergence of atypical El Tor strains hitherto in literature .Emergence of atypical El Tor strains harboring rstR-Cl in Fujian occurred since 1994 .Meanwhile ,novel mutation sites and ctxB genotypes were observed in Fujian isolates ,including diverse combination of ctxB genotypes in one strain and combination of biotype-specific sites in ctxB sequences .In summary ,molecular characterization of O 1 serogroup EVC strains from Fujian was unique and geography-associated .
