title: Quantitative expression of cholera toxin mRNA in Vibrio cholerae isolates with different CTX cassette arrangements.
abstract: Cholera toxin (CT) is the major virulence factor produced by Vibrio cholerae. Several genomic arrangements within the CTX cassette have been elucidated in V. cholerae. Previously, it was shown that three different CTX cassette arrangements, one complete CTX cassette (arrangement A), one complete and two incomplete CTX cassettes (arrangement B), and two complete CTX cassettes (arrangement C), exist within V. cholerae isolates. In the present study, the level of CT expression by V. cholerae isolates carrying different CTX cassette arrangements was evaluated. Real-time quantitative PCR analysis showed unequal production of CT mRNA in V. cholerae isolates with different CTX arrangements. V. cholerae with the CTX arrangement C expressed more CT mRNA than isolates with the other CTX arrangements. In addition, CT mRNA was expressed more in the isolates with CTX arrangement B than in those with arrangement A. Overall, these results suggest that the arrangement and number of regulatory elements (rstA) within the CTX cassette could affect the level of expression of CT.
authors.affiliation: Department of Microbiology, Pasteur Institute of Iran, Tehran, Iran.|Department of Microbiology & Immunology, Babol University of Medical Sciences, Babol, Iran.
authors.forename: Seyed Mahmoud
authors.initials: SM
authors.lastname: Amin Marashi
authors.affiliation: Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
authors.forename: Bita
authors.initials: B
authors.lastname: Bakhshi
authors.affiliation: Applied Microbiology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
authors.forename: Abbas Ali
authors.initials: AA
authors.lastname: Imani Fooladi
authors.affiliation: Department of Microbiology, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Akbar
authors.initials: A
authors.lastname: Tavakoli
authors.affiliation: Science and Research Branch, Islamic Azad University, Tehran, Iran.
authors.forename: Afsoon
authors.initials: A
authors.lastname: Sharifnia
authors.affiliation: Department of Microbiology, Pasteur Institute of Iran, Tehran, Iran.
authors.forename: Mohammad R
authors.initials: MR
authors.lastname: Pourshafie
mesh_terms: D002772:Cholera Toxin / Q000096:biosynthesis* / Q000235:genetics; D020869:Gene Expression Profiling; D023061:Gene Order; D006801:Humans; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D014734:Vibrio cholerae / Q000235:genetics*; D037521:Virulence Factors / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D012333:RNA, Messenger; D037521:Virulence Factors; D002772:Cholera Toxin