Beschreibung:
<jats:title>ABSTRACT</jats:title>
<jats:p>
We identified five different putative
<jats:italic>wav</jats:italic>
gene cluster types, which are responsible for the synthesis of the core oligosaccharide (OS) region of
<jats:italic>Vibrio cholerae</jats:italic>
lipopolysaccharide. Preliminary evidence that the genes encoded by this cluster are involved in core OS biosynthesis came from analysis of the recently released O1 El Tor
<jats:italic>V. cholerae</jats:italic>
genome sequence and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of O1 El Tor mutant strains defective in three genes (
<jats:italic>waaF</jats:italic>
,
<jats:italic>waaL</jats:italic>
, and
<jats:italic>wavB</jats:italic>
). Investigations of 38 different
<jats:italic>V. cholerae</jats:italic>
strains by Southern blotting, PCR, and sequencing analyses showed that the O1 El Tor
<jats:italic>wav</jats:italic>
gene cluster type is prevalent among clinical isolates of different serogroups associated with cholera and environmental O1 strains. In contrast, we found differences in the
<jats:italic>wav</jats:italic>
gene contents of 19 unrelated non-O1, non-O139 environmental and human isolates not associated with cholera. These strains contained four new
<jats:italic>wav</jats:italic>
gene cluster types that differ from each other in distinct gene loci, providing evidence for horizontal transfer of
<jats:italic>wav</jats:italic>
genes and for limited structural diversity of the core OS among
<jats:italic>V. cholerae</jats:italic>
isolates. Our results show genetic diversity in the core OS biosynthesis gene cluster and predominance of the type 1
<jats:italic>wav</jats:italic>
gene locus in strains associated with clinical cholera, suggesting that a specific core OS structure could contribute to
<jats:italic>V. cholerae</jats:italic>
virulence.
</jats:p>