-
Infection and Immunity Mar 1983Human isolates of Actinomyces viscosus and Actinomyces naeslundii have been divided into six clusters in a numerical taxonomy study. Surface fibrils of strains... (Comparative Study)
Comparative Study
Human isolates of Actinomyces viscosus and Actinomyces naeslundii have been divided into six clusters in a numerical taxonomy study. Surface fibrils of strains representing these clusters were isolated and purified. Chemical analyses revealed that the major component of all fibrils was protein and that although differences in percentages of specific amino acid residues were found, the relative proportions of basic, acidic, polar uncharged, and nonpolar amino acids were rather similar among clusters. All of the fibrils except those from strain B236 (cluster 2) either failed to migrate or penetrated only slightly into gels during sodium dodecyl sulfate-polyacrylamide gel electrophoresis, even after boiling, reduction, or alkylation. Immunological studies by electron microscopic examination of fibril-antibody immunocomplexes, whole bacterial cell agglutination, inhibition of hemagglutination, and immunofluorescence by using antifibril antisera and antibodies demonstrated that strains of typical A. naeslundii (cluster 5) have a specific fibril-associated antigen(s) distinct from those of strains of other clusters. Cross-reactions for atypical A. naeslundii (cluster 3) were few. The fibrils from A. viscosus clusters 1, 2, 4, and 6 demonstrated several cross-reactions. By absorbing antifibril antibodies with cross-reactive strains it was possible to obtain cluster-specific antibodies, as determined by whole cell agglutination, only for cluster 5. Absorbed antifibril antisera for both A. naeslundii clusters 3 and 5 were specific by indirect immunofluorescence, whereas anti-cluster 1 fibril antisera cross-reacted only with other A. viscosus cluster representatives. Purification of Actinomyces fibrils by methods used for appendages of other species yields preparations containing common antigens among taxonomic groups. However, absorbing antifibril antisera, gamma globulin, or both has promise for producing cluster-specific reagents useful in identification.
Topics: Actinomyces; Amino Acids; Antigens, Bacterial; Bacterial Proteins; Cross Reactions; Epitopes; Fimbriae, Bacterial; Hemagglutination; Immune Sera; Species Specificity
PubMed: 6188696
DOI: 10.1128/iai.39.3.1325-1333.1983 -
Infection and Immunity Feb 1978Actinomyces viscosus ATCC 15987 was examined for the presence of cell-associated levan by absorption of myeloma proteins with antilevan activity and direct... (Comparative Study)
Comparative Study
Actinomyces viscosus ATCC 15987 was examined for the presence of cell-associated levan by absorption of myeloma proteins with antilevan activity and direct immunofluorescence. Levan was not detectable on the surface of glucose-grown A. viscosus, but after a brief incubation of these cells with 5% sucrose, they were encapsulated with tenaciously adhering levan. The levan layer constituted between 0.02 and 0.03% of the cell dry weight. In contrast, sucrose-grown A. viscosus cells possessed a low level of cell-associated levan, which was only moderately increased by incubation in sucrose and which partially existed as a loose slime rather than a tenacious capsule.
Topics: Actinomyces; Cell Wall; Dental Plaque; Fluorescent Antibody Technique; Glucose; Hemagglutination Tests; Myeloma Proteins; Polysaccharides, Bacterial; Sucrose
PubMed: 344220
DOI: 10.1128/iai.19.2.711-719.1978 -
Infection and Immunity Feb 1988Actinomyces viscosus LY7 cells adsorbed in high numbers to experimental pellicles formed on hydroxyapatite (HA) from human parotid or submandibular saliva but not to...
Actinomyces viscosus LY7 cells adsorbed in high numbers to experimental pellicles formed on hydroxyapatite (HA) from human parotid or submandibular saliva but not to pellicles prepared from human plasma or serum. To determine the nature of the salivary components responsible for promoting adhesion, pellicles were prepared from fractions of submandibular and parotid saliva obtained by chromatography on Trisacryl GF 2000 columns. Adsorption of LY7 cells was promoted by two groups of fractions. Each group was rechromatographed on DEAE-agarose. Fractions which promoted adsorption of LY7 cells were found by polyacrylamide gel electrophoresis to contain the acidic proline-rich proteins (PRPs) and statherin. Pellicles prepared from 12-micrograms/ml solutions of pure PRP-1, PRP-2, or parotid isoelectric focusing (PIF-slow) variant promoted maximal adsorption of A. viscosus LY7 cells. Somewhat higher concentrations of PRP-3 and PRP-4 were required for maximal adsorption, indicating that the 44-residue carboxy-terminal segment of PRP-1, PRP-2, and PIF-slow enhances LY7 binding but is not essential. Much higher concentrations of statherin were required to promote LY7 adsorption. Adsorption of LY7 cells to pellicles prepared from PRP-1 was not affected over the range of pH 5 to 8. Adsorption was also not inhibited by 50 mM lactose, which is consistent with the notion that type 1 fimbriae, rather than type 2 fimbriae, were responsible. A. viscosus T14, Actinomyces odontolyticus ATCC 17982, and Actinomyces israelii 12597 also adsorbed to PRP-1 pellicles, whereas Actinomyces naeslundii ATCC 12104 did not. Although A. viscosus cells bind strongly to adsorbed PRP-1, the presence of PRP-1 or PRP-3 in solution did not inhibit adhesion. Similarly, [3H]PRP-1 did not bind to LY7 cells, nor was it degraded when incubated with the organism. However, LY7 cells adsorbed to [3H]PRP-1 pellicles. These data suggest that hidden molecular segments of PRP become exposed when the protein adsorbs to HA; these segments then react with adhesins of LY7 cells. The apparent ability of A. viscosus cells to recognize segments of PRPs which are exposed only in surface-adsorbed molecules provides a novel mechanism which enables the organism to attach to teeth when suspended in salivary secretions.
Topics: Actinomyces; Adsorption; Bacterial Adhesion; Dental Plaque; Fimbriae, Bacterial; Hydroxyapatites; Peptide Fragments; Salivary Proteins and Peptides
PubMed: 2892794
DOI: 10.1128/iai.56.2.439-445.1988 -
Oral Microbiology and Immunology Feb 1996A monoclonal antibody to Actinomyces naeslundii (A. viscosus) T14V-J1 type 1 fimbriae, capable of inhibiting the adherence of this bacterium to salivary proline-rich... (Comparative Study)
Comparative Study
A monoclonal antibody to Actinomyces naeslundii (A. viscosus) T14V-J1 type 1 fimbriae, capable of inhibiting the adherence of this bacterium to salivary proline-rich protein-treated hydroxyapatite, was generated by immunization of SWR mice with A. naeslundii 55-19, a strain derived from T14V-J1 that possess only type 1 fimbriae. Supernatants of hybridomas were screened for reactivity with purified type 1 fimbriae. An IgG monoclonal antibody, 86-49E, blocked the adsorption of the parent strain to proline-rich protein-treated hydroxyapatite by 77% with 1.0 microgram/ml of the monoclonal antibody; the Fab fragment derived from this monoclonal antibody inhibited adherence by 38% at the same concentration. Similarly, the adherence of strain 55-19 was inhibited by 100% and 64% to proline-rich protein-treated hydroxyapatite with 1.0 micrograms/ml of IgG and Fab fragments respectively. Control monoclonal antibody to the subunit of type 1 fimbriae, as well as to Actinobacillus actinomycetemcomitans caused only minimal adherence inhibition. Monoclonal antibody 86-49E also agglutinated both type 1 fimbriae-bearing strains of A. naeslundii T14V-J1 and 55-19 but not strains 59-51 and 147, which lack type 1 fimbriae. Further confirmation of the specificity of monoclonal antibody 86-49E was obtained using these fimbria-deficient mutant strains in an enzyme-linked immunosorbent assay, with the monoclonal antibody binding only to strains possessing type 1 fimbriae. Immunogold labeling in conjunction with electron microscopy suggested binding of monoclonal antibody 86-49E occurring near the distal end of the fimbriae. In contrast, when a monoclonal antibody specific for the type 1 fimbrial subunit but not capable of adherence inhibition was used together with 86-49E in double-labeling experiments, extensive labeling of the fimbriae by the subunit antibody was noted. These data suggest that a monoclonal antibody specific for the type 1 fimbriae of A. naeslundii that is capable of binding to a discrete site on the fimbriae has the capacity to inhibit the adsorption of this organism to saliva-treated hydroxyapatite.
Topics: Actinomyces viscosus; Adhesins, Bacterial; Animals; Antibodies, Bacterial; Antibodies, Monoclonal; Antibody Specificity; Bacterial Adhesion; Bacterial Outer Membrane Proteins; Durapatite; Female; Fimbriae, Bacterial; Immunoglobulin Fab Fragments; Immunoglobulin G; Immunohistochemistry; Mice; Mice, Inbred Strains; Microscopy, Electron; Protein Binding; Saliva
PubMed: 8604255
DOI: 10.1111/j.1399-302x.1996.tb00336.x -
Journal of Bacteriology Apr 1991Interbacterial adhesion (coadhesion) is considered a major determinant of dental plaque ecology. In this report, we studied several aspects of the adhesion of...
Interbacterial adhesion (coadhesion) is considered a major determinant of dental plaque ecology. In this report, we studied several aspects of the adhesion of Porphyromonas (Bacteroides) gingivalis to hexadecane in order to use the liquid hydrocarbon as a convenient substratum for coadhesion assays. Washed suspensions of hydrophobic P. gingivalis 2561 cells were vortexed with hexadecane to yield highly stable cell-coated droplets. Kinetics of coadhesion between Actinomyces viscosus cells and P. gingivalis-coated hexadecane droplets (PCHD) was subsequently studied. Aliquots of PCHD were added to A. viscosus suspensions, and the mixtures were gently rotated. Avid adhesion of A. viscosus cells to the immobilized P. gingivalis layer could be readily measured by the decrease in turbidity in the aqueous phase, following phase separation. Despite the ability of A. viscosus cells to adsorb to hexadecane following vigorous mixing, gentle mixing did not appreciably promote adhesion to bare hexadecane. Moreover, extensive microscopic examinations revealed that A. viscosus cells adhered exclusively to the bound P. gingivalis cells rather than to exposed areas of hexadecane. Coadhesion of A. viscosus to the PCHD appeared to follow first-order kinetics, attaining 80% levels within 30 min. Electron micrographs revealed A. viscosus cells adhering to the P. gingivalis cell layer adsorbed at the hexadecane-water interface. Interestingly, P. gingivalis cells did not appear to penetrate the hexadecane. A viscosus mutants lacking type 1 or type 2 fimbriae or both were still able to bind to the PCHD. No obvious correlation was observed between relative hydrophobicity of A. viscosus strains and their binding to PCHD. However, defatted bovine serum albumin, an inhibitor of hydrophobic interactions, was the most potent inhibitor among those tested. The data suggest that this approach provides a simple, quantitative technique for studying kinetics of bacterial coadhesion which is amenable to both light and electron microscopic observation.
Topics: Actinomyces; Alkanes; Arginine; Asparagine; Bacterial Adhesion; Bacteroides; Lysine; Microscopy, Electron; Phenylalanine; Serum Albumin, Bovine
PubMed: 1901571
DOI: 10.1128/jb.173.8.2581-2589.1991 -
Infection and Immunity Feb 1980Laboratory strains representing six numerical taxonomy clusters and fresh isolates of human Actinomyces viscosus and Actinomyces naeslundii were studied by standard...
Laboratory strains representing six numerical taxonomy clusters and fresh isolates of human Actinomyces viscosus and Actinomyces naeslundii were studied by standard flocculation slide tests for the ability to hemagglutinate erythrocytes (RBC) from various animal species. Human AB and horse RBC were agglutinated more frequently and rapidly than others; guinea pig RBC were agglutinated by only a few strains. Human AB RBC were selected for studies of hemagglutination mechanisms. Treatment of RBC with clostridial neuraminidase (NTRBC) greatly enhanced hemagglutination for almost all strains. In hapten inhibition experiments in which various concentrations of sugars were used, beta-galactosides were the most effective inhibitors of hemagglutination for both RBC and NTRBC; inhibition of NTRBC agglutination required higher concentrations. Soybean lectin agglutinated both RBC and NTRBC but not Actinomyces cells. NTRBC agglutinated at a 125-fold-lower concentration. Hemagglutination was sensitive to ethylenediaminetetraacetate for one strain tested. Hemagglutination reactions were reversible by addition of beta-galactosides. The ability of Actinomyces strains to "prime" RBC for hemagglutination by removing sialic acid to expose more penultimate beta-galactoside sites was studied by recycling Actinomyces-agglutinated RBC which were dispersed with a lactose solution and washed free of bacteria (primed RBC). Priming in this manner augmented subsequent hemagglutination by indicator Actinomyces strains and made the RBC more sensitive to agglutination by soybean lectin. The priming ability of Actinomyces strains generally correlated with the amount of sialic acid removed from primed RBC. Strains representing the numerical taxonomy clusters differed in both their hemagglutinating and priming activities. Cluster 5 strains (typical A. naeslundii) were good agglutinators of RBC, NTRBC, and primed RBC but were poor primers. Cluster 3 strains (atypical A. naeslundii) were the weakest hemagglutinators but could prime RBC adequately for subsequent agglutination by other strains. Together, these data indicate that Actinomyces hemagglutination proceeds via a two-step mechanism: (i) neuraminidase removal of terminal sialic acid and (ii) lectin-like binding to exposed beta-galactoside-associated sites on the RBC. Strains differ in the extent to which they can perform the two functions, and this specificity may relate to their taxonomic classification.
Topics: Actinomyces; Animals; Carbohydrates; Edetic Acid; Galactosides; Guinea Pigs; Hemagglutination; Horses; Humans; Lectins; Neuraminidase
PubMed: 6769798
DOI: 10.1128/iai.27.2.335-343.1980 -
Journal of Dental Research Mar 1984Actinomyces viscosus and Actinomyces naeslundii differ in their abilities to colonize tooth and epithelial surfaces. These differences appear to be associated with the...
Actinomyces viscosus and Actinomyces naeslundii differ in their abilities to colonize tooth and epithelial surfaces. These differences appear to be associated with the distribution of different fimbriae on the two species and with the distinct adherence-related functions of these structures.
Topics: Actinomyces; Adhesiveness; Adsorption; Adult; Antigens, Bacterial; Fimbriae, Bacterial; Hemagglutination; Humans; Hydroxyapatites; Saliva; Streptococcus sanguis
PubMed: 6142065
DOI: 10.1177/00220345840630030701 -
Infection and Immunity Oct 1987There is limited evidence, mostly indirect, to suggest that the adherence of Bacteroides gingivalis to teeth may be enhanced by the presence of gram-positive dental...
There is limited evidence, mostly indirect, to suggest that the adherence of Bacteroides gingivalis to teeth may be enhanced by the presence of gram-positive dental plaque bacteria like Actinomyces viscosus. The purpose of this study was to carry out direct quantitative assessments of the cohesion of B gingivalis and A. viscosus by using an in vitro assay modeled on the natural sequence in which these two species colonize the teeth. The assay allowed comparisons to be made of the adherence of 3H-labeled B. gingivalis 2561 and 381 to saliva-coated hydroxyapatite beads (S-HA) and A. viscosus WVU627- or T14V-coated S-HA (actinobeads) in equilibrium and kinetics binding studies. A series of preliminary binding studies with 3H-labeled A. viscosus and parallel studies by scanning electron microscopy with unlabeled A. viscosus were conducted to establish a protocol by which actinobeads suitable for subsequent Bacteroides adherence experiments could be prepared. By scanning electron microscopy, the actinobeads had only small gaps of exposed S-HA between essentially irreversibly bound A. viscosus cells. Furthermore, B. gingivalis cells appeared to bind preferentially to the Actinomyces cells instead of the exposed S-HA. B. gingivalis binding to both S-HA and actinobeads was saturable with at least 2 X 10(9) to 3 X 10(9) cells per ml, and equilibrium with saturating concentrations was reached within 10 to 20 min. B. gingivalis always bound in greater numbers to the actinobeads than to S-HA. These findings provide direct measurements supporting the concept that cohesion with dental plaque bacteria like A. viscosus may foster the establishment of B. gingivalis on teeth by enhancing its adherence.
Topics: ABO Blood-Group System; Actinomyces; Bacterial Adhesion; Bacteroides; Culture Media; Female; Humans; Kinetics; Male; Microscopy, Electron, Scanning; Microspheres; Models, Biological; Saliva; Scintillation Counting; Tooth
PubMed: 3653983
DOI: 10.1128/iai.55.10.2391-2397.1987 -
Journal of Dental Research May 1990Studies on the microbiology of root surface caries between 1970 and 1975 placed emphasis on Gram-positive pleomorphic filamentous rods, particularly Actinomyces viscosus... (Review)
Review
Studies on the microbiology of root surface caries between 1970 and 1975 placed emphasis on Gram-positive pleomorphic filamentous rods, particularly Actinomyces viscosus and Actinomyces naeslundii. Both of these species had been shown to produce root surface caries in experimental animals. Since this time, studies have placed more emphasis on Streptococcus mutans, and S. mutans and Lactobacillus are significant in prediction of root surface caries risk in patients. Subsequent studies confirmed an association between S. mutans and 'soft' or 'initial' root lesions. Thus, it is important when determining the microflora of root surface lesions to make careful characterization of the state of the lesion. A second important aspect of the analysis of bacterial communities associated with root surface caries is better definition of the organisms. Most studies have concentrated on 'target organisms' S. mutans, S. sanguis, A. viscosus, A. naeslundii, Lactobacillus, and Veillonella. However, it has been known for 17 years that the Actinomyces associated with the lesions may be variants of A. viscosus and A. naeslundii. Such strains (intermediate strains) have been described in taxonomic studies of Actinomyces, yet little is known of the differences in physiology of these strains or their relationship to root surface caries. A similar situation exists with oral Streptococcus where new taxonomic divisions are being proposed. Recognition of the potential diversity within the 'target' genera of root surface caries could yield valuable data. Recent studies suggest that this is so, since samples from root surface lesions which contain S. mutans and Lactobacillus show a high isolation of S. mitis 1 and no isolations of A. naeslundii. Careful definition of the lesions of root surface caries and the flora will allow analysis to relate a specific bacterial community to the state fo the lesion and assist in monitoring the control of the lesion through fluoride and antibacterials.
Topics: Actinomyces; Dental Caries; Humans; Lactobacillus; Streptococcus; Tooth Root
PubMed: 2186069
DOI: 10.1177/00220345900690051701 -
Caries Research 1988The relative glycogen synthetic and degradative activities of Actinomyces viscosus and Actinomyces naeslundii, freshly isolated from root surface caries and noncaries...
The relative glycogen synthetic and degradative activities of Actinomyces viscosus and Actinomyces naeslundii, freshly isolated from root surface caries and noncaries sites, were compared. The glycogen synthetic activity was measured by incubating glucose-(or sucrose-)grown resting cells with 100 mM glucose (or sucrose) and U-[14C]-glucose (or U-[14C]-sucrose) on a pH-stat maintained at 5.0, 6.0, and 7.0 for 1 h under anaerobic conditions. For the glycogen degradation assays, after the 1-hour incubation period, the cells were reincubated under similar conditions, but in the absence of external carbon sources. Carbohydrate utilization and total acid formation were also monitored. Both the glucose- and sucrose-grown cells of A. viscosus and A. naeslundii strains originating from root surface caries lesions synthesized approximately twice as much glycogen as the strains of noncaries origin. Although there were significant differences in the rates of glycogen synthesis, the rates of glycogen degradation were essentially the same for the Actinomyces strains from both caries and noncaries sites. However, the time required for glycogen degradation by the strains from caries sites was much longer. This study suggests that the abilities of A. viscosus and A. naeslundii originating from root surface caries lesions to synthesize large amounts of glycogen and to degrade this stored polymer slowly under conditions of starvation, particularly in an acidic environment, may be one of the factors contributing to the cariogenic potential of these organisms in root surface caries.
Topics: Actinomyces; Dental Caries; Dental Plaque; Glucose; Glycogen; Hydrogen-Ion Concentration; Sucrose; Tooth Root
PubMed: 3165713
DOI: 10.1159/000261109