The species 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 . Type 1 fimbriae mediate binding of cells to salivary proline-rich proteins. Specific polyclonal antisera against type 1 and type 2 fimbriae of T14V revealed both types of fimbriae on serovar WVA963 strain PK1259. To investigate the role of type 2 fimbriae of strain PK1259 in 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 Cogstrain 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 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 Cogmutant PK3092. These blots revealed a 95 kDa putative adhesin in the parent strain PK2399 that was absent in the Cogmutant 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.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error