title: Molecular cloning and genetic analysis of the rfb region from Shigella flexneri type 6 in Escherichia coli K-12.
abstract: The rfb gene cluster which determines the biosynthesis of the Shigella flexneri serotype 6 O-antigen specificity has been cloned in pHC79, generating plasmids pPM3115 and pPM3116. These plasmids mediate expression, in Escherichia coli K-12, of lipopolysaccharides (LPS) immunologically similar to the S. flexneri type 6 LPS as judged by SDS-PAGE and Western-immunoblot analysis using S. flexneri type 6 specific antisera. Thus, unlike other S. flexneri serotypes, no additional loci are required for serotype specificity. This expression is independent of E. coli K-12 rfb genes. Southern-hybridization analysis using the 16.2-kb BglII probe from S. flexneri type 6 rfb region detected very little sequence homology in S. flexneri serotypes 1-5, however, some homology was detected with E. coli O2 and O18, but not in E. coli 0101 strains, Salmonella and Vibrio cholerae.
authors.affiliation: Department of Microbiology and Immunology, University of Adelaide, South Australia.
authors.forename: K C
authors.initials: KC
authors.lastname: Cheah
authors.forename: D W
authors.initials: DW
authors.lastname: Beger
authors.forename: P A
authors.initials: PA
authors.lastname: Manning
mesh_terms: D015139:Blotting, Southern; D015153:Blotting, Western; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D004926:Escherichia coli / Q000235:genetics*; D005798:Genes, Bacterial; D005838:Genotype; D008070:Lipopolysaccharides / Q000302:isolation & purification; D005810:Multigene Family; D010641:Phenotype; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid; D012763:Shigella flexneri / Q000235:genetics*
chemical_list: D004269:DNA, Bacterial; D008070:Lipopolysaccharides