%0 Journal Article %A Fallarino, Angelo %A Attridge, Stephen R. %A Manning, Paul A. %A Focareta, Tony %T Cloning and characterization of a novel haemolysin in Vibrio cholerae O1 that does not directly contribute to the virulence of the organismbbThe GenBank accession number for the sequence reported in this paper is AJ007495. %D 2002 %J Microbiology, %V 148 %N 7 %P 2181-2189 %@ 1465-2080 %R https://doi.org/10.1099/00221287-148-7-2181 %K δ-VPH, δ-thermostable haemolysin of V. parahaemolyticus %K KP, Kanagawa phenomenon %K TRH, TDH-related haemolysin %K thermostable %K TLH, thermolabile haemolysin %K virulence factor acyl-CoA synthetase %K TDH, thermostable direct haemolysin %K Vc-δTH, δ-thermostable haemolysin of V. cholerae %K enteric disease %I Microbiology Society, %X 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 δ-thermostable direct haemolysin of Vibrio parahaemolyticus, and so it has been termed V. cholerae δ-thermostable haemolysin (Vc-δTH, 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-δTH 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-δTH. A V. cholerae Z17561 dth::KmR mutant showed unaltered behaviour in the infant mouse cholera model. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-148-7-2181