HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Fallarino, A. Articles by Focareta, T. Search for Related Content PubMed PubMed Citation Articles by Fallarino, A. Articles by Focareta, T. Agricola Articles by Fallarino, A. Articles by Focareta, T.

Cloning and characterization of a novel haemolysin in Vibrio cholerae O1 that does not directly contribute to the virulence of the organism^b

Microbial Pathogenesis Unit, Discipline of Microbiology and Immunology, Department of Molecular Biosciences, The University of Adelaide, Adelaide, SA 5005, Australia¹

Author for correspondence: Tony Focareta. Tel: +61 8 83034149. Fax: +61 8 83034362. e-mail: antonio.focareta{at}adelaide.edu.au

A previously undescribed haemolysin, distinct from the major Vibrio cholerae O1 El Tor haemolysin, HlyA, was cloned from the O1 classical biotype strain Z17561. This novel haemolysin showed 71·5% overall similarity to the -thermostable direct haemolysin of Vibrio parahaemolyticus, and so it has been termed V. cholerae -thermostable haemolysin (Vc-TH, encoded by the dth gene). An ORF found immediately downstream, which appears to be transcriptionally and translationally linked to dth, displayed strong homology to the family of acyl-CoA synthetases. When expressed from an inducible promoter in Escherichia coli, Vc-TH was shown to be a 22·8 kDa protein active on sheep red blood cells. Co-expression of acs with dth had no effect on the haemolytic activity or cytoplasmic localization of Vc-TH. A V. cholerae Z17561 dth::Km^R mutant showed unaltered behaviour in the infant mouse cholera model.

Keywords: enteric disease, virulence factor acyl-CoA synthetase, thermostable

Abbreviations: KP, Kanagawa phenomenon; TDH, thermostable direct haemolysin; TLH, thermolabile haemolysin; TRH, TDH-related haemolysin; Vc-TH, -thermostable haemolysin of V. cholerae; -VPH, -thermostable haemolysin of V. parahaemolyticus

^b The GenBank accession number for the sequence reported in this paper is AJ007495.

^a Present address: AstraZeneca R & D Boston, 35 Gatehouse Drive, Waltham, MA 02451, USA.