Escherichia coli clone Sonnei (Shigella sonnei) had a chromosomal O-antigen gene cluster prior to gaining its current plasmid-borne O-antigen genes.

ABSTRACT: O antigen is part of the lipopolysaccharide present in the outer membrane of gram-negative bacteria. The surface-exposed O antigen is subject to selection by the host immune system, which may account for the maintenance of many different O-antigen forms. Characteristically, all genes specific to O-antigen synthesis are clustered in a region close to the his and gnd genes on the chromosome of Escherichia coli and related species. Shigella sonnei, essentially a clone of E. coli (E. coli clone Sonnei), is an important human pathogen and is unusual in that its O-antigen gene cluster is located on a plasmid. Our results suggest that it once had a normal chromosomal O-antigen gene cluster which has been largely deleted. We suggest that the O antigen encoded by the plasmid-borne genes offered a s

SUBMITTER: Lai V 

PROVIDER: S-EPMC107268 | biostudies-literature | 1998 Jun

REPOSITORIES: biostudies-literature