title: Capsular polysaccharide production and serum survival of Vibrio vulnificus are dependent on antitermination control by RfaH.
abstract: The human pathogen Vibrio vulnificus undergoes phase variation among colonial morphotypes, including a virulent opaque form which produces capsular polysaccharide (CPS) and a translucent phenotype that produces little or no CPS and is attenuated. Here, we found that a V. vulnificus mutant defective for RfaH antitermination control showed a diminished capacity to undergo phase variation and displayed significantly reduced distal gene expression within the Group I CPS operon. Moreover, the rfaH mutant produced negligible CPS and was highly sensitive to killing by normal human serum, results which indicate that RfaH is likely essential for virulence in this bacterium.
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA.
authors.forename: Shana B
authors.initials: SB
authors.lastname: Garrett
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA.
authors.forename: Katherine L
authors.initials: KL
authors.lastname: Garrison-Schilling
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA.
authors.forename: Jeffrey T
authors.initials: JT
authors.lastname: Cooke
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA.
authors.forename: Gregg S
authors.initials: GS
authors.lastname: Pettis
mesh_terms: D016667:Bacterial Capsules / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D007136:Immunoglobulins / Q000097:blood / Q000494:pharmacology; D050296:Microbial Viability / Q000187:drug effects; D009154:Mutation; D009876:Operon; D010445:Peptide Elongation Factors / Q000172:deficiency / Q000235:genetics*; D010641:Phenotype; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D015534:Trans-Activators / Q000172:deficiency / Q000235:genetics; D041261:Vibrio vulnificus / Q000187:drug effects / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D037521:Virulence Factors / Q000172:deficiency / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D007136:Immunoglobulins; D010445:Peptide Elongation Factors; D011135:Polysaccharides, Bacterial; D011994:Recombinant Proteins; D015534:Trans-Activators; D037521:Virulence Factors
keywords: capsular polysaccharide; phase variation; serum survival; transcriptional antiterminator