Cloning and molecular characterization of a unique hemolysin gene of Vibrio pommerensis sp nov.:: development of a DNA probe for the detection of the hemolysin gene and its use in identification of related Vibrio spp. from the Baltic Sea

A group of hemolytic Vibrio strains was isolated from surface water of the Baltic Sea in 1995. A typical representative strain, CH-291, was found to lyse washed human and animal erythrocytes. Hemolysis was found to be calcium-dependent and occurred over a temperature range from 25 to 37degreesC. The hemolysin-encoding genes were identified by screening a genomic library of total DNA from strain, CH-291. A cloned chromosomal DNA fragment of 15.6 kb conferred to Escherichia coli DH5alpha a hemolytic phenotype. Hybidization and sequence analysis showed the cloned sequence to be unique to these Baltic Sea Vibrio isolates and therefore provides a useful marker for their identification. Moreover, the cloned 15.6-kb DNA fragment possessed structural features typical for genetic island, including a decreased GC content and a flanking cryptic insertion sequence element. (C) 2003 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved.