title: Genes involved in the synthesis and degradation of matrix polysaccharide in Actinobacillus actinomycetemcomitans and Actinobacillus pleuropneumoniae biofilms.
abstract: Biofilms are composed of bacterial cells embedded in an extracellular polysaccharide matrix. A major component of the Escherichia coli biofilm matrix is PGA, a linear polymer of N-acetyl-D-glucosamine residues in beta(1,6) linkage. PGA mediates intercellular adhesion and attachment of cells to abiotic surfaces. In this report, we present genetic and biochemical evidence that PGA is also a major matrix component of biofilms produced by the human periodontopathogen Actinobacillus actinomycetemcomitans and the porcine respiratory pathogen Actinobacillus pleuropneumoniae. We also show that PGA is a substrate for dispersin B, a biofilm-releasing glycosyl hydrolase produced by A. actinomycetemcomitans, and that an orthologous dispersin B enzyme is produced by A. pleuropneumoniae. We further show that A. actinomycetemcomitans PGA cross-reacts with antiserum raised against polysaccharide intercellular adhesin, a staphylococcal biofilm matrix polysaccharide that is genetically and structurally related to PGA. Our findings confirm that PGA functions as a biofilm matrix polysaccharide in phylogenetically diverse bacterial species and suggest that PGA may play a role in intercellular adhesion and cellular detachment and dispersal in A. actinomycetemcomitans and A. pleuropneumoniae biofilms.
authors.affiliation: Medical Science Building, Room C-636, 185 S. Orange Ave., Newark, NJ 07103, USA. kaplanjb@umdnj.edu
authors.forename: Jeffrey B
authors.initials: JB
authors.lastname: Kaplan
authors.forename: Kabilan
authors.initials: K
authors.lastname: Velliyagounder
authors.forename: Chandran
authors.initials: C
authors.lastname: Ragunath
authors.forename: Holger
authors.initials: H
authors.lastname: Rohde
authors.forename: Dietrich
authors.initials: D
authors.lastname: Mack
authors.forename: Johannes K-M
authors.initials: JK
authors.lastname: Knobloch
authors.forename: Narayanan
authors.initials: N
authors.lastname: Ramasubbu
mesh_terms: D000117:Acetylglucosamine / Q000737:chemistry; D016977:Actinobacillus pleuropneumoniae / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D016976:Aggregatibacter actinomycetemcomitans / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D018441:Biofilms / Q000254:growth & development*; D005798:Genes, Bacterial; D006801:Humans; D008969:Molecular Sequence Data; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D017422:Sequence Analysis, DNA
chemical_list: D001426:Bacterial Proteins; D011135:Polysaccharides, Bacterial; D000117:Acetylglucosamine