Open AccessClassical and El Tor Biotypes of Vibrio cholerae Differ in Timing of Transcription of tcpPH during Growth in Inducing Conditions
Author(s) -
Yvette M. Murley,
Jaideep Behari,
Robert W. Griffin,
Stephen B. Calderwood
Publication year - 2000
Publication title -
infection and immunity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.508
H-Index - 220
eISSN - 1070-6313
pISSN - 0019-9567
DOI - 10.1128/iai.68.5.3010-3014.2000
Subject(s) - biology , vibrio cholerae , transcription (linguistics) , el tor , cholera toxin , virulence , transcription factor , cholera , gene , promoter , genetics , microbiology and biotechnology , gene expression , bacteria , linguistics , philosophy
Two protein pairs inVibrio cholerae , ToxRS and TcpPH, are necessary for transcription from thetoxT promoter and subsequent expression of cholera virulence genes. We have previously shown that transcription oftcpPH in classical strains ofV. cholerae is activated at mid-log-phase growth in ToxR-inducing conditions, while transcription oftcpPH in El Tor strains is not. In this study, we showed that while transcription oftcpPH differs at mid-log-phase growth in ToxR-inducing conditions between the biotypes, transcription is equivalently high during growth in AKI conditions. We usedtcpPH ::gusA transcriptional fusions to quantitate expression oftcpPH in each biotype throughout growth in ToxR-inducing conditions and showed that although transcription oftcpPH is reduced at mid-log-phase growth in an El Tor strain, transcription is turned on later in growth to levels in excess of those in the classical strain (although cholera toxin is not produced). This suggests that the difference in expression of cholera virulence factors in response to ToxR-inducing conditions between the El Tor and classical biotypes ofV. cholerae may be related to the timing of transcription oftcpPH rather than the absolute levels of transcription.