Cloning of a gene encoding a unique haemolysin from Klebsiella pneumoniae and its potential use as a species-specific gene probe

A gene, designated khe, that encodes a haemolysin of Klebsiella pneumoniae CMC-1 has been cloned and sequenced. When expressed in Escherichia coli, a unique peptide of approximately 20 kDa was identified. Nucleotide sequence analysis predicted a single open reading frame (ORF) of 486 bp encoding a162 amino acid polypeptide with an estimated pl of 6.77. No extensive sequence homology could be identified between khe and any reported sequence at either the nucleotide or amino acid level. Furthermore, DNA hybridizations under high stringency conditions failed to show any cross hybridizations to several bacteria including K. oxytoca, K. planticola, K. terrigena and K. ornithinolytica. These data indicate that we have cloned a unique gene, which is highly conserved among tested K. pneumoniae isolates. (C) 2002 Published by Elsevier Science Ltd.