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PubMed1991

Interactions of sanguinarine and zinc on oral streptococci and Actinomyces species.

Sanguinaria extract, which contains benzophenanthridine alkaloids, has been used as a folk medicine for many years. Minimum inhibitory and minimum bactericidal concentrations (MIC and MBC values) for sanguinarine were determined for common and etiologically important plaque bacteria. Because the efficacy of sanguinarine is believed to be enhanced by zinc, isobolograms were assessed to determine their mode(s) of interaction. Hydrogen ion concentration influenced the inhibitory activity of both sanguinarine and zinc. For sanguinarine, at the optimum pH (6.5), MIC values were 4 or 8 micrograms/ml for Streptococcus mutans, Streptococcus sobrinus, Streptococcus sanguis, Actinomyces viscosus and Actinomyces naeslundii. MIC values were 0.125-0.50 mmol Zn/ml. MBC values ranged from 1 to 8 mmol Zn/ml at pH 5.5. Isobologram data revealed that sanguinarine and zinc interacted synergistically. Viadent oral rinse, which contained 300 micrograms sanguinaria extract/ml and 0.2% zinc chloride (14.9 mmol Zn/l), was inhibitory to all strains tested. MIC values were 1 or 2% (ml Viadent oral rinse/100 ml aqueous solution) for all strains except A. viscosus for which the MIC value was 12% (vol/vol).

Actinomyces↗

PubMed1995

Streptococci and actinomyces inhibit regrowth of Streptococcus mutans on gnotobiotic rat molar teeth after chlorhexidine varnish treatment.

Clinical studies suggest that the long-term suppression of mutans streptococci on tooth surfaces after intensive chlorhexidine therapy is mainly due to bacterial interference. Other streptococci and also Actinomyces naeslundii are proposed to inhibit regrowth of mutans streptococci after suppression by the agent. We have tested this hypothesis in gnotobiotic rats associated with Streptococcus mutans alone, or associated with S. mutans and strains of Streptococcus oralis, Streptococcus sanguis, Streptococcus gordonii, Streptococcus mitis biovar I, and A. naeslundii. Left lower jaws in these rats were treated with concentrated chlorhexidine varnish, and the return of S. mutans on the treated jaws monitored. In mono-associated rats, S. mutans regained the level of the untreated right lower jaw in approximately 1 week. In contrast, S. mutans remained suppressed for several weeks in rats multi-associated with other streptococci and actinomyces strains. The suppression was more pronounced in the rats fed on basal diet with little free sugars than in rats fed on a sucrose-containing diet. Counts of other streptococci recovered quickly from the intensive chlorhexidine treatment, but A. naeslundii remained suppressed for at least 1 week. The findings demonstrate the crucial importance of the oral microflora in controlling regrowth of mutans streptococci after chemotherapy.

Actinomyces↗

PubMed1982

Thoracic actinomycosis caused by actinomyces meyeri.

Two patients with chest infections caused by Actinomyces meyeri were seen during a 5-yr period. One patient was ill for 2 yr and had chronic infection manifested by bilateral cavitary and fibrotic changes on chest roentgenogram. A. meyeri was isolated from a chest wall lesion, transtracheal aspirate, and lung tissue. The other patient presented with a subcutaneous abscess of the left hip that yielded A. meyeri on culture. A localized lung infection and empyema were found. Both patients had other aerobes or anaerobes recovered from material haboring A. meyeri, a frequent finding in actinomycosis caused by Actinomyces israelii. To our knowledge, thoracic actinomycosis caused by A. meyeri has not been previously described.

Actinomyces↗

PubMed1984

A conceptual model for the co-existence of Streptococcus spp. and Actinomyces spp. in dental plaque.

One of the most important questions in ecology is how to explain the co-existence of the variety of physiologically related organisms in the same habitat. A model is presented for the co-existence of Streptococcus species and Actinomyces species in dental plaque. The hypothesis is that these organisms co-exist because they simultaneously utilize several carbon and energy substrates. The hypothesis follows from the observation that the growth yield of oral streptococci and actinomyces in saliva is limited by carbohydrate. Preliminary experiments were undertaken to test the hypothesis using mixed chemostat cultures and gnotobiotic rats. Competition between S. mutans K1R and A. viscosus Ut2 in mixed chemostat cultures on glucose and asparagine was hampered by the early appearance of high-glucose-affinity variants of A. viscosus. From the physiological characteristics of S. sanguis and S. milleri, it might be predicted that simultaneous utilization of carbohydrate and arginine would enable these organisms to co-exist with S. mutans in an ecosystem. To test this mechanism under natural conditions, germ-free rats were inoculated with a combination of S. mutans K1R and S. sanguis P4A7 or the combination S. mutans K1R and S. milleri B448. The rats were fed on three different diets: (1) 58% cornstarch; (2) 48% cornstarch and 10% sucrose; and (3) 53% cornstarch and 5% arginine. The results of this experiment demonstrated that dietary arginine caused a significant decrease of the ratios K1R/P4A7 and K1R/B448 in dental plaque.(ABSTRACT TRUNCATED AT 250 WORDS)

Actinomyces↗

PubMed1985

In vitro attachment, salivary agglutination, and surface fibril density of fresh Actinomyces isolates from two distinct oral surfaces.

Whereas attachment specificity among bacterial species is well recognized, the question of specificity among strains of the same species isolated from distinct oral surfaces has not been studied. Twenty strains of Actinomyces, freshly isolated as they re-populated the cleaned teeth and tongues of a male twin pair, were compared for: (1) their ability to attach to saliva-coated hydroxyapatite (SHA), (2) the density of their surface fibrils, (3) their agglutination in saliva, and (4) their ability to agglutinate human erythrocytes. Differences among the strains were mostly along species rather than tissue source lines. The A. naeslundii strains were the least efficient in SHA attachment and had the least number of fibrils, but they were the most strongly agglutinated strains in saliva. The A. viscosus strains, while showing some tissue source differences in hemagglutination, were consistently alike in SHA attachment and fibril density. Salivary agglutination did not correspond with the ability to attach to SHA. Considering the surface characteristics of the Actinomyces species studied, strains of the same species isolated from distinct oral surfaces are apparently more alike than strains of the two closely-related species isolated from the same surface.

Actinomyces↗

PubMed1986

Actinomyces adsorption mediated by type-1 fimbriae.

Monospecific antibody against the type-1 fimbriae of Actinomyces viscosus T14V reacted with 12 strains of A. viscosus (serotype 2), 12 strains of A. naeslundii (serotype 2 or serotype 3), but not with 11 serotype 1 strains of A. naeslundii. All strains positive for the type-1 fimbrial antigen adsorbed strongly to saliva-treated hydroxyapatite, and in many instances (18 of 24 strains) this interaction was inhibited by the monospecific antibody. These findings strongly suggest that only those strains of actinomyces which possess type-1 fimbriae adhere to the tooth surfaces, and that these fimbriae constitute the principal adhesin involved in this interaction.

Actinomyces↗

PubMed1996

Effects of Actinomyces amphiphile on the fluidity of endothelial cells: a spin label study.

Actinomyces amphiphile (AcA) is an amphipathic molecule produced by Actinomyces viscosus that exhibits several biological activities. The effect of AcA on the fluidity and permeability of the plasma membrane in human umbilical vein endothelial cells was analyzed by a spin label method with 5- and 16-stearic acid nitroxide labels (SAL). These labels help to visualize the fluidity at the shallow (5-SAL) and deep (16-SAL) portions of the lipid bilayer. Cells were incubated with and without AcA (control) at 37 degrees C for 6 hours, and membrane fluidity was periodically measured. Another spin label, 4-(N, N-dimethyl-N-hexadecyl) ammonium-2, 2, 6, 6-tetramethyl-piperidine-1-oxyliodine (CAT-16), was also used to assess the physical state of the cell surface. The order parameter of 5-SAL was significantly lower in the cells incubated with AcA than in control cells after the six-hour incubation. The motion parameter of 16-SAL was significantly lower in AcA-treated cells than in controls after 4 and 6 hours of incubation. These findings indicated that the AcA increased the fluidity. There were no significant differences between the AcA-treated and control cells incubated for only 2 hours. In addition, there were no differences in CAT-16 measurements between AcA-treated and control cells. The release of endoplasmic lactate dehydrogenase (LDH) into the medium tended to increase in the AcA-treated vs. the control cells. LDH release increased in both a dose- and time-dependent manner, indicating that AcA increased the permeability of plasma membranes. These findings suggest that AcA alters the biophysical properties of the plasma membranes of endothelial cells, affecting membrane function.

Actinomyces viscosus↗

PubMed1999

Secretory immunoglobulin A heavy chain presents Galbeta1-3GalNAc binding structures for Actinomyces naeslundii genospecies 1.

Adherence of Actinomyces naeslundii ATCC 12104 to hydroxyapatite beads coated with protein fractions of parotid saliva, obtained by gel filtration on S-200 HR columns, showed GalNAcbeta1-3Galalpha-O-ethyl-inhibitable binding to high-molecular-weight proteins (Strömberg et al., 1992). The present study investigates the nature of these high-molecular-weight binding proteins and determines their specific ability to mediate adherence to representative strains of Actinomyces species. Strain ATCC 12104 bound specifically in a lactose-inhibitable manner to the heavy chain of secretory immunoglobulin A (S-IgA), contained within a high-molecular-weight parotid protein fraction separated on SDS-PAGE and transferred to a solid membrane support. Lactose-inhibitable binding to the heavy chain of S-IgA from human colostrum was also demonstrated. Peanut agglutinin bound to the heavy chain of parotid and colostrum S-IgAs contained on solid support membranes, confirming the presence of Galbeta1-3GalNAc residues on these molecules. Both salivary and colostrum S-IgA aggregated with strain ATCC 12104 in a GalNAcbeta1-3Galalpha-O-ethyl-inhibitable fashion. Further separation of high-molecular-weight salivary proteins on S-500 HR columns showed GalNAcbeta1-3Galalpha-O-ethyl-inhibitable binding to both mucin- and S-IgA-containing fractions. The presence of S-IgA in salivary pellicles formed in vivo on teeth was demonstrated by Western blot analysis of pellicle extracts with anti-IgA antibodies. Among strains representing A. naeslundii genospecies 1 and 2 and A. odontolyticus, only those of genospecies 1 with a particular adherence profile showed efficient GalNAcbeta1-3Galalpha-O-ethyl-inhibitable binding to S-IgA. Thus, oligosaccharides on S-IgA may promote bacterial aggregation (or adherence) and provide a mechanism by which S-IgA can interact with bacteria without prior immunological challenge.

Actinomyces↗

PubMed1999

Glucose and lactate metabolism by Actinomyces naeslundii.

Actinomyces are among the predominant bacteria in the oral microflora. This review discusses the glucose and lactate metabolism of Actinomyces naeslundii and its ecological significance in dental plaque. This bacterium has the Embden-Meyerhof-Parnas (EMP) pathway as the main route to degrade glucose. The EMP pathway-derived metabolic intermediates, phosphoenolpyruvate (PEP) and pyruvate, are further converted into different end-products, depending on the environment. Under anaerobic conditions in the absence of bicarbonate, the pyruvate is converted into lactate by a lactate dehydrogenase. In the presence of bicarbonate, the PEP is combined with bicarbonate and then converted into succinate through the succinate pathway, while the pyruvate is converted into formate and acetate through the pyruvate formate-lyase pathway. Under aerobic conditions, the pyruvate liberates acetate and CO2 through a pathway initiated by a pyruvate dehydrogenase. A. naeslundii strains also degrade lactate, aerobically, to acetate and CO2 through the conversion of lactate into pyruvate by a NAD-independent lactate dehydrogenase. These strains also synthesize glycogen from a glycolytic intermediate, glucose 6-phosphate. Besides atmospheric conditions and bicarbonate, the intracellular reduction-oxidation potential, carbohydrate concentration, and environmental pH also modulate the metabolism of A. naeslundii. Some of the phosphorylating enzymes involved in A. naeslundii metabolism--e.g., GTP/polyphosphate (PPn)-dependent glucokinase, pyrophosphate (PPi)-dependent phosphofructokinase, UDP-glucose pyrophosphorylase, and GDP/IDP-dependent PEP carboxykinase--are unique to A. naeslundii and have not been found in other oral bacteria. The utilization of PPn and PPi as phosphoryl donors, together with glycogen synthesis and lactate utilization, could contribute to the efficient energy metabolism found in A. naeslundii. Through this flexible and efficient metabolic capacity, A. naeslundii can adapt to fluctuating environments and compete with other bacteria in dental plaque. Further, this bacterium may modify the dental plaque environment and promote the microbial population shifts in dental plaque.

Actinomyces↗

PubMed1987

Osteomyelitis of the foot due to Actinomyces meyeri: a case report.

Anaerobic osteomyelitis occurs uncommonly with Actinomyces as a cause of approximately half of the reported cases. Although Actinomyces is a common organism in the mouth flora, it is an uncommon pathogen in osteomyelitis occurring in the extremity. The following reports the only known case of anaerobic osteomyelitis of the foot secondary to A. meyeri.

Actinomyces↗

PubMed2004

Salivary receptors for the proline-rich protein-binding and lectin-like adhesins of oral actinomyces and streptococci.

Colonization of the tooth surface by actinomyces and viridans group streptococci involves the attachment of these bacteria to adsorbed salivary components of the acquired enamel pellicle. The hypothesis that this attachment depends on specific adhesins has now been assessed from the binding of bacteria with well-defined adhesive properties to blots of SDS-PAGE-separated parotid and submandibular-sublingual (SM-SL) saliva. Streptococcus sanguis and type 2 fimbriated Actinomyces naeslundii, which bound terminal sialic acid and Galbeta1-3GalNAc, respectively, recognized only a few SM-SL salivary components, primarily MG2. In contrast, type 1 fimbriated A. naeslundii and S. gordonii, which bound purified proline-rich proteins (PRPs), recognized several other components from both SM-SL and parotid saliva. Significantly, bacteria that lacked PRP-binding and the lectin-like activities detected by binding to MG2 failed to bind any immobilized salivary component. These findings suggest the involvement of specific adhesins in bacterial recognition of many adsorbed salivary proteins and glycoproteins.

Actinomyces↗

PubMed1976

Light and electron microscopic observations of osteoclastic alveolar bone resorption in rats monoinfected with Actinomyces naeslundii.

Alveolar bone destruction in rats monoinfected with Actinomyces naeslundii proceeds via osteoclastic resorption. The osteoclastic activity is discontinuous, i.e. short periods of vigorous osteoclastic activity are followed by longer periods of inactivity during which the alveolar crest may be covered with osteoblastic cells or in many cases devoid of bone cells. The net effect in the monoinfected rats is rapid bone loss. Periods of osteoclastic activity were associated with dense inflammatory infiltration of the interdental tissue, ulceration of col epithelium and the presence of large adherent plaques of Actinomyces. Ultrastructural examination revealed uninuclear as well as multinuclear osteoclasts. These cells contained numerous mitochondria, abundant Golgi apparatuses, and well developed ruffled borders indicating that they were physiologically active in bone resorption.

Actinomyces↗

PubMed1983

Actinomyces israelii in the genital tract of women with and without intra-uterine contraceptive devices.

Actinomycosis involving the female genital tract is more common among IUD users than others. The diagnosis is difficult and often delayed. It has been suggested that the finding of Actinomyces-like organisms or A. israelii in cervical smears indicates a risk of developing actinomycosis. A. israelii has not been regarded as a part of the indigenous genital flora. A group of IUD users without symptoms of genital tract infections were compared with a control group without IUDs. No Actinomyces-like organisms were found on cytological examination of cervical smears. Immunofluorescent staining and cultures identified A. israelii in 4% of the IUD users and in 3% of the non-users. Serologic precipitin tests for actinomycosis were negative in all women. None developed actinomycosis on follow-up of positive cases. The study indicates that A. israelii is a commensal of the female genital tract. The identification of A. israelii alone does not indicate that the patient risks developing actinomycosis. Other methods such as a serology test should be useful in defining the clinical significance of the findings.

Actinomyces↗

PubMed1982

Novel antigens of oral Actinomyces species prepared from a cell wall enzyme lysate.

Purified cell walls of Actinomyces viscosus and Actinomyces naeslundii were solubilized by the enzymatic action of Ml N-acetylmuramidase. Soluble cell wall carbohydrate antigens were purified by column chromatography. A purified antigen preparation (fraction C) from A. viscosus ATCC 19246 was found to contain deoxyhexoses (rhamnose and 6-deoxytalose), hexosse (galactose, glucose and mannose), and a peptidoglycan component. This preparation gave a single precipitin band against antiserum to homologous whole cells. Similar antigen preparations were purified from Ml enzyme lysate of A. viscosus SK4 and A. naeslundii ATCC 12104 cell walls.

Actinomyces↗

PubMed1976

[Electron microscopic study of the structure of colonies of culture of Actinomyces parvullus producing actinomycin D].

Ultrafine structure of the mycellium of the colonies of active and non-active variants of Actinomyces parvullus, producing actinomycin D was studied. Functional rebuilding of the cells of the substrate and aerial mycellium during the colony development in connection with synthesis and accumulation of the antibiotic by the culture was shown. The process of production and secretion of an amorphous material in the cells of the substrate mycellium of the active variant of Actinomyces parvullus was studied. It was supposed that the above process was associated with the antibiotic synthesis by the organism cells. The phenomenon of intrahyphal growth of the hyphae observed in both the active and inactive variants of the colonies was rather characteristic of the cells of the culture studied.

Actinomyces↗

PubMedDate not supplied

[Review of the systematic position of Actinomyces orientalis (Pittenger et Brigham) Krass. 1970 and its reclassification as Proactinomyces orientalis (Pittenger et Brigham) comb. nov].

The micromorphology, growth cycle, chemical composition of the cell walls, and the susceptibility to lysozyme and specific phages were studied with the culture of Actinomyces orientalis RIA-1074. It is seggested on the basis of these studied to transfer the culture from the Actinomyces genus to the Proactinomyces genus and to rename it Proactinomyces orientalis (Pittinger et Brigham) comb. nov.

Actinomyces↗

PubMedDate not supplied

[Lysogeny in heat-tolerant hydrocarbon-oxidizing actinomycetes of species Actinomyces griseomycini].

Six strains of thermophilic hydrocarbon-oxidizing Actinomyces griseomycini were tested for lysogeny. The lysogenic state was detected in the four strains and their phages were isolated. The phages isolated from the three strains were virulent and cause lysis of the host culture. All isolated phages were specific and did not cause lysis of other actinomycetes species. However, the phages had different activity towards the six studied strains of Actinomyces griseomycini. One phage induced lysis only of its indicator culture, other phages caused lysis of four strains, including those two from which no phage was isolated. All phages produced negative colonies of identical morphology. The morphology of their particles was also the same. The phages induced cross-resistance and were characterized by thermoresistance.

Actinomyces↗

PubMed1992

[An ischiorectal abscess due to Actinomyces].

Actinomycosis is a chronic granulomatous inflammatory disease, with fistulization tendency, caused by Actinomyces. The clinical observation in presented of a patient with intermittent fever of three weeks duration, associated to pain and functional impotence of the right hip, observing with CT Scan an ischium-rectal abscess. After spontaneous fistulization, Actinomyces israelii was isolated in the biopsy sample by culture in anaerobic medium, confirming the diagnosis by anatomo-pathology. The patient was treated with intravenous penicillin for six weeks, followed by six months of oral treatment with which the symptoms disappeared and the radiological images normalized. Bone infection ranges between 1 and 15% of total actinomycosis.

Abscess↗