Sequence diversity in the major fimbrial subunit gene (flp-1) of Actinobacillus actinomycetemcomitans.
Oral Microbiol Immunol
; 17(6): 354-9, 2002 Dec.
Article
em En
| MEDLINE
| ID: mdl-12485326
Cells of the periodontal pathogen Actinobacillus actinomycetemcomitans exhibit tight adherence to surfaces such as glass, plastic and hydroxyapatite, a property that probably plays an important role in the ability of this bacterium to colonize teeth and other surfaces. Tight adherence is mediated by long fibrils of bundled pili (fimbriae) that form on the surface of the cell. The flp-1 gene encodes the major pilin protein component of A. actinomycetemcomitans fimbriae. In this study we compared flp-1 DNA sequences from 43 strains of A. actinomycetemcomitans isolated in Europe, Japan and the United States and identified seven distinct flp-1 allelic classes. DNA and predicted protein sequences were almost completely conserved within each flp-1 class but were highly divergent between classes. Most amino acid substitutions occurred in the C-terminus of the pilin protein, a region that has been shown to be important for the bundling and adhesive properties of the pili. flp-1 classes correlated with serotypes and 16S rRNA genotypes in most strains. At least five strains showed evidence of horizontal transfer of flp-1 between strains of different serotypes and 16S rRNA genotypes. Four of the seven flp-1 classes were present in geographically diverse isolates. Strains representing all seven flp-1 classes, but not a strain carrying a transposon insertion in flp-1, bound avidly to polystyrene in an in vitro adherence assay. Strains representing six of the seven flp-1 classes were isolated from localized juvenile periodontitis patients, suggesting that phylogenetically diverse strains carry pathogenic potential. Our findings provide a framework for future biochemical, immunological and genetic studies of A. actinomycetemcomitans fimbriae.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Bactérias
/
Variação Genética
/
Aggregatibacter actinomycetemcomitans
/
Fímbrias Bacterianas
Tipo de estudo:
Prognostic_studies
Limite:
Adult
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
Oral Microbiol Immunol
Assunto da revista:
ALERGIA E IMUNOLOGIA
/
MICROBIOLOGIA
/
ODONTOLOGIA
Ano de publicação:
2002
Tipo de documento:
Article
País de afiliação:
Estados Unidos
País de publicação:
Dinamarca