Cloning and sequencing of a novel hemolysis gene of Vibrio cholerae.

A hemolysis gene (hlx) which lyses sheep erythrocytes on blood agar plates when expressed in Escherichia coli was cloned from Vibrio cholerae. The cloned gene is predicted to encode a polypeptide of 92 amino acid residues with a deduced molecular mass of 10,451. E. coli transformed with this gene lysed sheep, goose, horse and chicken erythrocytes but not those of guinea pig and human. The hlx gene was observed in classical- and El Tor-biotype V. cholerae O1, V. cholerae non-O1, and V. mimicus, but not in V. parahaemolyticus.