|
|
||||||||
1Laboratory of Microbial Ecology, National Institute of Dental Research, National Institutes of Health, Bethesda, MD 20892, USA
2Microbiology Research Group, School of Biological Sciences, Stopford Building, Manchester University, Oxford Road, Manchester M13 9PT, UK
ABSTRACT
The species Actinomyces serovar WVA963 is among the 20 bacteria most frequently isolated from human subgingival plaque. The interactions of this species with streptococci are inhibited by lactose, a function associated with type 2 fimbrial surface structures in Actinomyces naeslundii. Type 1 fimbriae mediate binding of cells to salivary proline-rich proteins. Specific polyclonal antisera against type 1 and type 2 fimbriae of A. naeslundii T14V revealed both types of fimbriae on Actinomyces serovar WVA963 strain PK1259. To investigate the role of type 2 fimbriae of strain PK1259 in Actinomyces-Streptococcus lactose-inhibitable coaggregations, spontaneous coaggregation-defective (Cog-) mutants that failed to coaggregate with streptococci were isolated; three were chosen for study. All three mutant strains synthesized type 1 fimbriae and a 59 kDa protein; mutant strains PK2415 and PK3092 synthesized type 2 fimbriae and a 57 kDa protein. In contrast, the Cog-strain PK2407 did not agglutinate with anti-type 2 antibodies or show the 57 kDa band, suggesting that the 57 kDa protein was the type 2 fimbrial subunit. Polyclonal antiserum raised against the Actinomyces serovar WVA963 strain PK2399, an antibiotic-resistant derivative of wild-type PK1259, blocked coaggregation between this strain and streptococci. Anti-PK2399 serum absorbed with mutant strain PK3092 bearing type 2 fimbriae retained its blocking ability. Surface sonicates of the parent and mutant strains were adsorbed to streptococcal cells and to lactose-agarose beads. Lactose eluates from both the streptococcal cells and the affinity beads were characterized by SDS-PAGE and corresponding immunoblots using anti-PK2399 serum absorbed with Cog-mutant PK3092. These blots revealed a 95 kDa putative adhesin in the parent strain PK2399 that was absent in the Cog-mutant strain PK3092. These results suggest the presence of a putative 95 kDa actinomyces adhesin distinct from the 57 kDa type 2 fimbrial subunit and that this adhesin mediates lactose-inhibitable coaggregation with streptococci.
*Author for correspondence: Paul E. Kolenbrander. Tel: +1 301 496 1497. Fax: +1 301 402 0396. e-mail: kolenbrander@yoda.nidr.nih.gov
This article has been cited by other articles:
![]() |
M. E. Davey and G. A. O'toole Microbial Biofilms: from Ecology to Molecular Genetics Microbiol. Mol. Biol. Rev., December 1, 2000; 64(4): 847 - 867. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Hallberg, C. Holm, U. Ohman, and N. Stromberg Actinomyces naeslundii Displays Variant fimP and fimA Fimbrial Subunit Genes Corresponding to Different Types of Acidic Proline-Rich Protein and beta -Linked Galactosamine Binding Specificity Infect. Immun., September 1, 1998; 66(9): 4403 - 4410. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| INT J SYST EVOL MICROBIOL | MICROBIOLOGY | J GEN VIROL |
| J MED MICROBIOL | ALL SGM JOURNALS | |