title: Analysis of a gene cluster of Enterococcus faecalis involved in polysaccharide biosynthesis.
abstract: Previously, we described a gene cluster of Enterococcus faecalis OG1RF that produced an antigenic polysaccharide when cloned in Escherichia coli. The polysaccharide antigen was not detectable in E. faecalis strains, however. Here, we show by reverse transcriptase-PCR that the 16 genes in this region are transcribed in OG1RF. Gene disruption of orfde4, encoding a putative glycosyl transferase, and orfde6, a putative dTDP-rhamnose biosynthesis gene, generated two OG1RF mutants. The mutants showed delayed killing and a higher 50% lethal dose in a mouse peritonitis model. In addition, two mucoid E. faecalis isolates from patients with chronic urinary tract infections were found to produce the polysaccharide antigen.
authors.affiliation: Department of Microbiology and Molecular Genetics, University of Texas Medical School, Houston, Texas 77030, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Xu
authors.forename: K V
authors.initials: KV
authors.lastname: Singh
authors.forename: X
authors.initials: X
authors.lastname: Qin
authors.forename: B E
authors.initials: BE
authors.lastname: Murray
authors.forename: G M
authors.initials: GM
authors.lastname: Weinstock
mesh_terms: D000818:Animals; D013293:Enterococcus faecalis / Q000235:genetics* / Q000254:growth & development / Q000276:immunology; D005798:Genes, Bacterial; D006801:Humans; D051379:Mice; D005810:Multigene Family; D009154:Mutation; D016366:Open Reading Frames; D010538:Peritonitis / Q000209:etiology; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis* / Q000276:immunology; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic
chemical_list: D011135:Polysaccharides, Bacterial; D012333:RNA, Messenger