Exclusive presence of lactose-sensitive fimbriae on a typical strain (WVU45) of Actinomyces naeslundii

Abstract

Lactose-sensitive fimbriae were identified as the only fimbriae present on Actinomyces naeslundii WVU45 (ATCC 12104). A single antigen reactive with antiserum against WVU45 cells was detected by cross immunoelectrophoresis of isolated fimbriae, and a monospecific antiserum against this antigen reacted with all fimbriae observed on the bacterial surface by immunoelectron microscopy. Moreover, the loss of one cell surface antigen by a spontaneous mutant of A. naeslundii WVU45 (WVU45M), isolated by its failure to react with a monospecific antibody against the fimbriae, was associated with the loss of all fimbriae. The functional involvement of the fimbriae in lactose-sensitive bacterial adherence was demonstrated by the ability of WVU45, but not WVU45M, cells to agglutinate neuraminidase-treated erythrocytes and by the lactose-sensitive hemagglutinating activity of immune complexes formed with isolated fimbriae and monospecific antibody. Bacterial agglutination assays with different monospecific antibodies revealed an antigenic similarity between the fimbriae of A. naeslundii WVU45 and the lactose-sensitive fimbriae (type 2) of Actinomyces viscosus T14V. In contrast, cross-reactivity was not observed between the WVU45 fimbriae and type 1 fimbriae, the structures involved in lactose-resistant adherence of strain T14V to saliva-treated hydroxyapatite. Functional differences between the fimbriae of A. naeslundii and A. viscosus strains may be correlated with well-established differences in the in vivo distribution of these organisms: namely, the preference of typical A. naeslundii for epithelial surfaces and of A. viscosus for tooth surfaces.

Pathogenicity of Actinomyces israelii and Arachnid propionica: experimental infection in guinea pigs and phagocytosis and intracellular killing by human polymorphonuclear leukocytes in vitro

“…The fimbriae play an important role by mediating adhesion to a variety of other cells and tissues. The type 1 fimbriae found on A. viscosus mediate bacterial attachment to the tooth surface and saliva-coated hydroxyapatite and the type 2 fimbriae are associated with a lectin activity that mediates the adhesion between epithelial cells and PMNs as well as coaggregation with other bacteria (11,12,36). The lectin associated with type 2 fimbriae has also recently been shown to produce a respiratory burst in PMNs, with the release of toxic oxygen intermediates and enzymes (37).…”

Binding of Actinomyces naeslundii to glycosphingolipids

“…Attachment of radioiodinated bacteria to the gangliosides was assessed on a duplicate chromatogram. The chromatogram was dipped in polyisobutylmethacrylate (Polysciences Inc., Warrington, Pa.) for 1 min and blocked with 0.5% bovine serum albumin in phosphate-buffered saline (0.02 M P043-, 0.15 M NaCl [pH 7.2]) for 2 h. A. naeslundii WVU45 was cultured as previously described (7); washed in Hanks balanced salt solution (Flow Laboratories, Inc., McLean, Va.) containing 0.2 mg of CaCl2 per ml, 0.2 mg of MgSO4 per ml, and 0.2% bovine serum albumin (HBSS'); adjusted to 109 cells per ml; and incubated for 1 h at 22°C with 25 ,ug of R64 rabbit immunoglobulin G per ml that is reactive with nonfimbrial bacterial surface antigens (6). The bacteria were * Corresponding author.…”

Identification of Polymorphonuclear Leukocyte and HL-60 Cell Receptors for Adhesins of Streptococcus gordonii and Actinomyces naeslundii

“…Bacteria. A. naeslundii WVU45 and WVU45M as well as S. gordonii DL1 (Challis) and M5 have been described (10,23,52). All bacteria were grown in complex medium, washed three times with Hanks balanced salt solution (Bio-Whittaker, Inc.), and adjusted to approximately 2 ϫ 10 9 bacteria per ml (turbidity, 260 Klett units).…”