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PubMed1987

Root surface caries subsequent to gingivectomy in rats inoculated with Streptococcus sobrinus (mutans) and Actinomyces viscosus.

We studied the effect of oral infection with cariogenic micro-organisms on alveolar bone loss and root surface caries subsequent to gingivectomy in rats. Thirty-six rats were fed diet MIT 200 (67% sucrose); one-half, the controls, had antibiotics added to the diet. At ages 18, 19, and 21 days, the experimental group was orally infected with streptomycin-resistant Streptococcus sobrinus (mutans) 6715 and Actinomyces viscosus M-100. At age 30 days, all animals were subjected to a gingivectomy on maxillary and mandibular left quadrants. The experimental group was re-inoculated at age 36 days. Animals were killed seven weeks after surgery. Jaws were stained, and planimetric measurements of exposed root surface area and caries on lingual/palatal surfaces of 1st and 2nd molars were made from video images with a computer/digitizer. Compared with the non-operated contralateral quadrants, gingivectomy significantly increased exposed root surface area in the maxilla and in the mandible in both the control and experimental groups. Oral inoculation significantly increased exposed root surface in mandibular (but not maxillary) quadrants which had received a gingivectomy, but had no effect on non-gingivectomized quadrants. There was no caries in the control group, whereas ten rats in the experimental group had root surface caries lesions, all in quadrants which had received a gingivectomy. This rat model should prove useful in further studies of root surface caries.

Actinomyces↗
PubMed1988

The effects of different levels of dietary sucrose on root caries subsequent to gingivectomy in conventional rats infected with Actinomyces viscosus M-100.

Three groups of weanling, Sprague-Dawley-derived rats were inoculated with Actinomyces viscosus M-100 and fed powdered diet containing either 67%, 5%, or 0% confectioner's sugar. Two further groups were fed diet containing 5% confectioner's sugar and inoculated with Streptococcus sobrinus 6715 or S. sobrinus 6715 plus A. viscosus M-100. The most coronal 1 mm of gingiva was removed from maxillary and mandibular right molar quadrants (gingivectomy), and the animals re-inoculated following gingivectomy. The animals were killed 64 days following gingivectomy, and the lingual surface of mandibular first molar roots was measured for exposed root-surface area and root caries. In the groups of rats infected with A. viscosus M-100, root caries area was significantly greater in the group fed diet containing 67% confectioner's sugar. Sucrose level did not significantly affect the amount of exposed lingual first molar root area regardless of whether the tooth had been subjected to a gingivectomy. In the groups of rats receiving diet containing 5% confectioner's sugar, there were no significant differences in root caries area or exposed root-surface area, regardless of the infection status of the animals. In the rat model presented here, a high level of dietary sucrose was a necessary condition for the initiation of root caries in the absence of other readily fermentable carbohydrates.

Actinomyces↗
PubMed1993

In vitro demineralization by strains of Actinomyces viscosus and Streptococcus sobrinus of sound and demineralized root surfaces.

Root sections were inoculated with one of two strains of Actinomyces viscosus or a strain of Streptococcus sobrinus and then incubated for 9 days in Trypticase soy broth (TSB) containing 0.25% glucose or TSB supplemented with 0.25% sucrose (TSB+S). Lesion progression was measured from microradiographs. One section from each group was examined with a transmission electron microscope. Lesion progression was associated with a fall in the pH of the medium. However, lesion progression was not correlated with the mean 48-hour pH of the medium. In both TSB and TSB + S, lesion progression with A. viscosus was significantly greater than in the S. sobrinus group. However, the mean 48-hour pH value in TSB + S was lower than that in the S. sobrinus group. Plaque formation in TSB was, subjectively, least in the S. sobrinus group. Examination of transmission electron micrographs revealed bacteria penetrating the surfaces of the sections and extending into the lesion in the A. viscosus groups but not in the S. sobrinus group. This in vitro bacterial plaque model of root caries may be suitable for investigations of the bacterial etiology of root-surface caries and the virulence factors associated with pathogenicity.

Actinomyces viscosus↗
PubMed1995

Assay of proteases from Actinomyces pyogenes isolated from pigs and cows by zymography.

Extracellular proteases of Actinomyces pyogenes were assayed by zymography on SDS-polyacrylamide gel with the concentrated culture supernatant of 7 isolates from pigs and cows. When gelatin was used as a substrate, three proteases with molecular weights of 69, 59 and 55 kilodalton (kDA) were detected in all the isolates from both the pigs and cows. In addition to these proteases, 108 and 102 kDa proteases were detected in the swine and bovine isolates respectively. No protease bands appeared, however, when the calcium ion was absent from the buffer solution of the zymography. When casein was used as a substrate, the bands of 69, 59 and 55 kDa proteases were present, but 108 and 102kDa proteases were not detected in any of the isolates. The activity of all proteases was completely inhibited by phenylmethyl-sulfonyl fluoride and diisopropyl fluorophosphate but not by other protease inhibitors. From this result, it seems likely that the five proteases produced by A, pyogenes, originating from pigs and cows, are serine proteases.

Actinomyces↗
PubMed1997

Lymph node abscess due to Actinomyces viscosus in a cat.

In a four-year-old male cat, a subcutaneous phyma about 3.5 cm in diameter was surgically removed from the left inframandibular region. Histopathologically, the phyma was found to be the swollen medial retropharyngeal lymph node containing an actinomycotic abscess. The filamentous organisms in the abscess stained positively by the Gram's, Grocott's and periodic acid-Schiff methods, and were negative by the Ziehl-Neelsen method. By the immunoperoxidase method, the organisms were specifically identified as Actinomyces viscosus serotype 2 by its antiserum absorbed with A. viscosus serotype 1 antigen.

Abscess↗
PubMed1989

Properties of sialidase isolated from Actinomyces viscosus DSM 43798.

The cell-bound sialidase of Actinomyces viscosus DSM 43798 was solubilized by mechanical cell disruption and lysozyme treatment. The enzyme was enriched 30,000-fold by cation-exchange chromatography, gel-filtration, and FPLC ion-exchange chromatography, thus obtaining 10 micrograms sialidase protein from 26 g wet cells with a specific activity of 680 U/mg protein. Since sialidase activity was also found in the culture medium, this enzyme was isolated as well, requiring the additional application of FPLC gel-filtration. Both sialidase preparations were apparently homogenous on SDS-PAGE and have similar properties. The substrate specificity of the A. viscosus sialidase was tested with 16 sialoglycoconjugates: The enzyme showed a higher activity with serum glycoproteins than with gangliosides, mucins or sialyllactoses. 4-O-Acetylated N-acetylneuraminic acid was not cleaved from equine submandibular gland mucins or serum glycoproteins in contrast to N-acetyl- and N-glycoloylneuraminic acid. 9-O-Acetyl-N-acetylneuraminic acid was released from bovine submandibular gland mucin, as confirmed by TLC. The sialidase hydrolyses alpha(2----6)-linkages more rapidly than alpha(2----8)- and alpha(2----3)-bonds. Cations, except Hg2+, or chelating agents have no influence on enzyme activity. The sialidase has a relatively high molecular mass of 150 kDa, but consists of only one unit. The enzyme is labile towards freezing and thawing, but can be stored at 4 degrees C in 0.1 M acetate buffer, pH 5.

Actinomyces↗
PubMed1991

Cloning, sequencing and expression of the sialidase gene from Actinomyces viscosus DSM 43798.

Chromosomal DNA from Actinomyces viscosus was digested with restriction endonucleases and the fragments ligated with pUC-vectors were used to transform Escherichia coli cells. Clones bearing the required sialidase gene were detected by spraying the colonies with the fluorogenic sialidase substrate MU-Neu5Ac. The identity of the cloned sialidase was confirmed after the 5700-fold enrichment and comparison with the purified enzyme of A. viscosus. Both sialidases were identical with regard to molecular mass, substrate specificity tested with sialyllactoses, and the inhibition of their activity by heterologous antisialidase antibodies. The sequenced insert (EMBL accession number X62276) revealed a mol% G + C of 68.2, typical for A. viscosus. An open reading frame of 2739 bp follows a sequence with dyad symmetry and an AG-rich region, and codes for 913 amino acids representing a molecular mass of 113 kDa. The conserved amino acid sequence [Ser-X-Asp-X-Gly-X-Thr-Trp] typical for bacterial sialidases was found at five positions in the predicted amino acid sequence. The gene of this enzyme is expressed by E. coli, despite the low relatedness of both species.

Actinomyces viscosus↗
PubMed1980

Cell-mediated immune response to fractionated products of Actinomyces viscosus cultures.

Since bacterial invasion of host tissue has not been shown to occur in the course of periodontitis, many investigators believe that products released from dental plaque microorganisms enter the tissue and elicit a series of host responses leading to the pathological condition. This study, therefore, was designed to explore the possibility that cell-free products isolated from Actinomyces viscosus cultures are able to induce cell-mediated immunological responses in experimental animals. Hartley strain guinea pigs were sensitized with concentrated cell-free products of A. viscosus culture supernatant fluids mixed with Freund complete adjuvant. After 10 to 17 days the animals responded to challenge with this material with skin reactions indicative of delayed-type hypersensitivity. Furthermore, cells isolated from sensitized animals produced mitogenic factor and macrophage migration inhibition factor (MIF) when cultured with the material. The cell-free culture products were fractionated by column chromatography and electrophoresis. Several partially purified components were shown to induce cell-mediated responses in guinea pigs as determined by skin tests and by mitogenic factor and MIF assays. It is apparent that this single microorganism associated with dental plaque is capable of producing several substances which can induce a cell-mediated immune response and subsequent tissue inflammation in laboratory animals.

Actinomyces↗
PubMed1981

Immune response to keyhole limpet hemocyanin and oral Actinomyces viscosus antigens in Macaca arctoides.

The humoral and cell-mediated immune response to keyhole limpet hemocyanin and antigens from a monkey oral strain of Actinomyces viscosus were investigated in Macaca arctoides. Prior to immunization no responses were detected. Immunization resulted in the production of antibodies to both antigen preparations, the development of a positive skin test and significant stimulation of peripheral blood lymphocytes using the in vitro lymphocyte blastogenesis technique. Furthermore, these responses were continuously detectable for more than 1 year postimmunization with keyhole limpet hemocyanin and for up to 6 months postimmunization with A. viscosus antigens. The capability of developing immune responses in these animals, particularly to A. viscosus antigens, added further to their use as a model for the study of the role of the host immune response to these antigens in the pathogenesis of human periodontal disease.

Actinomyces↗
PubMed1989

Caries on root surfaces exposed following gingivectomy in conventional rats infected with Streptococcus sobrinus and Actinomyces viscosus.

To study the ability of bacteria associated with coronal caries to initiate root surface caries, a rat model was used. Root surfaces were exposed by gingivectomy in rats fed a caries-promoting diet and orally inoculated with either Actinomyces viscosus M-100, Streptococcus sobrinus (mutans) 6715, or both. A fourth group received a diet containing antibiotics. The animals were sacrificed 64 days following the gingivectomy performed on the right molar quadrants. Gingivectomy significantly increased exposed lingual root length and root caries incidence. There were no caries on non-gingivectomy root surfaces. Root surface caries incidence in the groups inoculated with A. viscosus and A. viscosus plus S. sobrinus did not differ. For both these groups, root caries incidence was significantly greater than that for the group inoculated with S. sobrinus alone. Root caries incidence in this latter group did not differ from that in the control group.

Actinomyces↗
PubMed1989

The effect of ofloxacin on experimental periodontitis in hamsters infected with Actinomyces viscosus ATCC 15987.

Syrian hamsters were infected with Actinomyces viscosus ATCC 15987 by inoculation into the oral cavity to induce experimental periodontitis. The effect of an antibiotic, ofloxacin (OFLX), on the experimental periodontitis was examined. In Group A, OFLX gel was applied daily to the gingival mucosa, 2 weeks after bacterial inoculation. Groups B and C were an infected control and a noninfected control, respectively. The hamsters in these three groups were fed a powdered high-sucrose diet. The hamsters in Group D, also a noninfected group, were fed an ordinary solid diet. Salivary occult blood test, evaluation of gingival and plaque index, measurement of alveolar bone loss, bacterial examination, and histological observation were performed 11 weeks after infection. Group B exhibited significantly higher levels of gingival index, plaque index, and alveolar bone loss than the noninfected controls. Severe inflammation of the gingivae, formation of gingival pockets, migration of many inflammatory cells, and obvious bone loss were also observed in Group B. However, these inflammatory changes were milder in Group A, which was treated with OFLX.

Actinomyces↗
PubMed2005

Salivary Actinomyces naeslundii genospecies 2 and Lactobacillus casei levels predict pregnancy outcomes.

BACKGROUND: Gravida's poor periodontal health is emerging as a modifiable independent risk factor for preterm delivery and low birth weight. METHODS: To test the hypothesis that oral bacteria other than periodontal pathogens are also associated with pregnancy outcomes, specific oral bacterial levels measured during pregnancy were evaluated in relation to gestational age and birth weight while controlling for demographic, medical, and dental variables. The study population consisted of 297 predominantly African- American women who were pregnant for the first time. The salivary bacterial levels evaluated were Streptococcus mutans, Streptococcus sobrinus, Streptococcus sanguinus, Lactobacillus acidophilus, Lactobacillus casei, Actinomyces naeslundii genospecies (gsp) 1 and 2, total streptococci, and total cultivable organisms. RESULTS: For 1 unit increase in log(10) A. naeslundii gsp 2 levels, there was a 60 gm decrease in birth weight (beta = -59.7 g; SE = 29.1; P = 0.04), and a 0.17 week decrease in gestational age (beta = -0.17 wk; SE = 0.09; P = 0.05). In contrast, per 1 unit increase in log(10) L. casei levels, there was a 42 gm increase in birth weight (beta = 42.2 g; SE = 19.3; P = 0.03), and a 0.13 week increase in gestational age (beta = 0.13 week; SE = 0.06; P = 0.04). CONCLUSIONS: We conclude that other oral bacterial species can also be related to pregnancy outcomes in addition to previously reported periodontal pathogens. These organism levels may not only predict poor pregnancy outcomes, but also be used as modifiable risk factors in reducing prematurity and low birth weight.

Actinomyces↗
PubMed2003

Lung abscess caused by Actinomyces odontolyticus.

A 64-year-old woman with periodontal disease was admitted because of fever, right chest pain, and bloody sputum. Her chest radiograph revealed a nodular shadow in the right middle lung fields. From the results of a needle aspiration biopsy, she was diagnosed with a lung abscess due to Actinomyces odontolyticus (A. odontolyticus) and Streptococcus spp. The patient improved quickly with antibiotics. To our knowledge, only nine cases of pulmonary infection due to A. odontolyticus have been reported, and we report the first case in Japan. Although respiratory disease caused by A. odontolyticus is rare, the association of this organism should be considered even in healthy individuals.

Actinomyces↗
PubMed1984

A longitudinal study of Actinomyces israelii in the female genital tract.

A prospective longitudinal investigation was performed to study variations in the occurrence of Actinomyces israelii with reference to four microorganisms, staphylococci, E. coli, P. acnes and C. albicans, in the female genital tract. Fifteen healthy women were studied during all phases of the menstrual cycle. Sampling was made from the cervix, vagina and perineal area three times a week during two consecutive menstrual periods and during menstruation from napkins and tampons. Altogether 1108 samples were taken on 349 sampling occasions for different cultural procedures. A. israelii was identified in all women, in varying frequencies (range 4 to 74% of sampling occasions). As a mean, A. israelii was recovered in 24% of the perineal samples, 13% of the vaginal and 6% of the cervical samples. The occurrence of A. israelii was related neither to the recovery of reference microorganisms nor to the phase of the menstrual cycle, the amount of bleeding or discharge, the pH of the vaginal specimens, the contraceptive method used, or to the use of different sanitary products. It is our conclusion that A. israelii appears to be a part of the indigenous genital flora of healthy women.

Actinomyces↗
PubMed1992

Disseminated actinomycosis due to Actinomyces meyeri and Actinobacillus actinomycetemcomitans.

A 44-year-old man presented with pulmonary lesions and neurological symptoms suggestive of lung carcinoma with cerebral metastases. He had non-specific chest X-ray findings since 6 years and he also suffered from relapsing purulent skin lesions which resolved spontaneously or by short courses of antibiotic treatment. When corticosteroids were given, multiple subcutaneous swellings developed that spontaneously ruptured. The pus contained Actinomyces meyeri and Actinobacillus actinomycetemcomitans. On operation, the intracerebral lesions appeared to be abscesses and the same bacteria were cultured as from the skin lesions. Bronchoscopical examination did not reveal a diagnosis. Amoxicillin was given for 12 months and the patient recovered.

Actinobacillus Infections↗
PubMedDate not supplied

Necrotizing funisitis associated with Actinomyces meyeri infection: a case report.

Necrotizing funisitis is associated with an increased rate of stillbirth, perinatal infection, and preterm delivery. No one organism has been associated with necrotizing funisitis, although this condition has been linked with congenital syphilis in some studies. We report a case of necrotizing funisitis in a 24-year-old G2P0A2 woman who experienced preterm labor at 31 weeks of gestation. Examination of the placenta revealed severe chorioamnionitis and necrotizing funisitis; large numbers of gram-positive filamentous branching organisms could be seen on the surface of the cord and within Wharton jelly. Initial cultures of the placenta, which had not been maintained under anaerobic conditions after delivery, were negative. A fragment of the cord was then homogenized; anaerobic culture on brain-heart infusion agar yielded Actinomyces meyeri. This organism usually resides in the periodontal sulcus and has not been previously reported in the female genital tract. The mother gave a history of a dental abscess that flared up and drained with each of her three pregnancies; the pain was particularly severe during the last 2 months of this pregnancy, so she had the tooth removed after delivery. The infant was treated for prematurity and presumed sepsis and did well.

Actinomyces↗
PubMed1976

Endocarditis caused by Actinomyces viscosus.

A case of severe endocarditis caused by Actinomyces viscosus is described in a previously healthy 70-year-old man. The isolated strain has been characterized by biochemical tests, gas-liquid chromatography and serology. The pathogenic significance of the organism is discussed and the difficulty in reaching a correct diagnosis due to the similarity to species of Corynebacterium is pointed out.

Actinomyces↗
PubMed1977

Antimicrobial in vitro susceptibility of actinomyces israelii and arachnia propionica.

46 reference strains and clinical isolated of Actinomyces israelli and 8 strains of Arachnia propionica--the causative microorganisms of actinomycosis in man--were tested for their in vitro susceptibility to penicillin, sulfaisodimidine, erythromycin, tetracycline, lincomycin, clindamycin, metronidazole and tinidazole by the agar dilution method. All strains were susceptible to benzylpenicillin (minimum inhibitory concentrations, MICs of less than or equal to 0.064 mug/ml). Many strains were resistant in vitro to sulfaisodimidine (MICs 4.0-32.0 mug/ml). Erythromycin, tetracycline, clindiamycin and lincomycin possessed in vitro activity at concentrations readily attainable in serum. Due to adverse side-effects associated with clindamycin and lincomycin therapy, erythromycin and tetracycline may be the best alternative drugs to penicillin in the treatment of actinomycosis. In contrast, in vitro resistance (MICs greater than or equal to 4.0 mug/ml) of the pathogenic actinomycetes to metronidazole and tinidazole implies that these drugs may not be valuable in the therapy of human actinomycosis.

Actinomyces↗