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At least 433 records · Page 24Linked to original sources
PubMed1997

A rare case of disseminated actinomycosis caused by Actinomyces meyeri.

A case of disseminated actinomycosis caused by Actinomyces meyeri in a 43-year-old man is described. The patient presented with signs of pericarditis, weight loss, dry cough, and subsequently an inferior vena cava syndrome. Diagnosis of thoracic as well as abdominal actinomycosis was made 4 months after admission. This article stresses the importance of considering the diagnosis of the disease. Cure was achieved by administering penicillin for several months.

Actinomyces↗
PubMed1997

Inhibition of a Porphyromonas gingivalis colonizing factor between Actinomyces viscosus ATCC 19246 by monoclonal antibodies against recombinant 40-kDa outer-membrane protein.

1. Porphyromonas gingivalis, an important pathogen in human periodontal disease, aggregates with Actinomyces viscosus ATCC 19246. 2. Monoclonal antibodies (mAbs) against purified recombinant 40-kDa outer-membrane protein (r40-kDa, OMP) of P. gingivalis 381 inhibited its coaggregation with A. viscosus ATCC 19246 in a dose-dependent manner. 3. Five mAb clones against r40-kDa OMP were selected. The isotype of the five was IgG1. 4. Pg-ompA2 inhibited the coaggregation of several strains of P. gingivalis with A. viscosus ATCC 19246 cells.

Actinomyces viscosus↗
PubMed2002

Identification of a new biotype of Actinomyces hyovaginalis in tissues of pigs during diagnostic bacteriological examination.

Bacterial strains isolated from a large variety of necropsy samples of pigs and previously described as a phenotypical homogeneous group were shown to belong to the species Actinomyces hyovaginalis. This was unexpected because their colonial characteristics, as well as their origins, were very different from those originally reported for the vaginal strains on which the species description of A. hyovaginalis was based. Colonial morphology, as well as fermentation of cellobiose, reactions in hippurate and nitrate and production of beta-glucuronidase, allowed separation of the strains studied here from the vaginal strains. Analysis of tRNA intergenic length polymorphisms (tDNA-PCR), 16S rRNA-gene sequencing and DNA-DNA hybridizations were carried out and led to the proposal of a separate biotype within the species A. hyovaginalis. Since, the strains were isolated from different body sites, this biotype has been designated as the 'general' biotype of A. hyovaginalis, while the strains on which the original species description was based are designated as the 'vaginal' biotype.

Actinomyces↗
PubMed1990

Typing of Actinomyces pyogenes by its production and susceptibility to bacteriocin-like inhibitors.

A scheme for "fingerprinting" of Actinomyces pyogenes strains based on their production of (P-typing) and the sensitivity to (S-typing) bacteriocin-like substances has been developed. P-typing and S-typing of 42 A. pyogenes cultures with a set of 9 micrococcal and staphylococcal species as indicator strains and 9 streptococcal species as bacteriocin producer strains revealed 10 P types and 7 S types, respectively. The bacteriocin "fingerprinting" procedure might provide a means for subdividing A. pyogenes and may find application in epidemiological studies.

Actinomyces↗
PubMed1993

Adherence of Actinomyces pyogenes to HeLa cells mediated by hydrophobic surface proteins.

Determination of cell-surface hydrophobicity of Actinomyces pyogenes by hydrophobic interaction chromatography on phenyl-Sepharose revealed that all 42 cultures examined were strongly hydrophobic. The hydrophobic surface proteins were solubilized by mutanolysin treatment of the bacteria and isolated by hydrophobic interaction chromatography. In SDS-PAGE, they appeared with numerous protein bands and blocked the adhesion of whole bacterial cells to the gel matrix. The A. pyogenes cultures attached to HeLa cells in varying degrees. This attachment of A. pyogenes was greatly reduced in the presence of isolated hydrophobic proteins and in the presence of specific antibodies produced against hydrophobic surface proteins. The results of the present study demonstrate that hydrophobic surface proteins promote the capacity of A. pyogenes to adhere to HeLa cells.

Actinomyces↗
PubMed1993

Antimicrobial susceptibility testing of Actinomyces pyogenes: comparison of disk diffusion test and Api ATB Strep system with the agar dilution method.

The use of the disk diffusion and the Api ATB Strep system or a related technique for a few antibiotics was compared with the agar dilution method for antimicrobial susceptibility testing of 103 clinical isolates of Actinomyces pyogenes. There was complete agreement between disk diffusion and MIC in 98.8%, with minor errors, in 0.7% and with very large errors, in 0.5% of cases. The common criteria for the interpretation of zones could be kept for penicillin G, amoxicillin, methicillin, cephalothin, erythromycin, lincomycin, pristinamycin, vancomycin, rifampin, streptomycin, kanamycin, gentamicin and chloramphenicol. The proposed breakpoints for a tetracycline 30 IU disk were > or = 22 mm for susceptibility and < 22 mm for resistance. There was complete agreement between the ATB strip system and MIC in 98.3% of cases, with minor errors in 0.9% and with very large errors, in 0.8% of cases. All the dissimilarities were due to streptomycin and tetracycline and results could not be reported for these 2 antibiotics when using this system. Wells with kanamycin and gentamicin at low concentrations as well as chloramphenicol should be included by the manufacturer.

Actinomyces↗
PubMed1994

Molecular typing of Actinomyces pyogenes isolates.

The molecular characterization of 28 clinical Actinomyces pyogenes strains was attempted. SDS-PAGE protein profiles did not allow to distinguish isolates. Restriction endonuclease analysis of total DNA gave the finest differentiation between strains but the profiles were difficult to read. Ribotypes after DNA digestion by Bst EII or Sma I have a high discriminatory power and are more helpful epidemiological markers. No relationship could be demonstrated between molecular types and clinical sources.

Actinomyces↗
PubMed1989

Characterization of extracellular neuraminidase produced by Actinomyces pyogenes.

Extracellular neuraminidase from Actinomyces pyogenes could be isolated by ammonium sulfate precipitation, ion exchange chromatography with DEAE cellulose and gel filtration on Ultrogel ACA 54. The purified enzyme had a molecular weight of approximately 50,000 Dalton, a pH optimum at pH 6.0, a temperature optimum at 55 degrees C and a Km value of 1.4 X 10(-4) mol/l with N-acetyl-neuraminlactose as substrate. Preparative isoelectric focussing of the culture supernatant revealed neuraminidase activity mainly at pH 6.5. The enzyme activity was not influenced by metalions or EDTA.

Actinomyces↗
PubMed1989

Isolation and characterization of an extracellular protease of Actinomyces pyogenes.

An extracellular protease from Actinomyces pyogenes ATCC 19411 could be isolated by ion exchange chromatography with DEAE cellulose and high performance gel filtration (FPLC) on Superose 12 prep grade. The purified enzyme had a relative molecular mass of approximately 37,000 Dalton, a pH optimum at 7.5, a temperature optimum at 50 degrees C, and a Km value of 2.2 mg/ml with azocasein as substrate. The enzyme activity was clearly inhibited by PMSF, EDTA, the metal ion Zn++ and only weakly by Cd++ and Co++. Preparative isoelectric focussing of the culture supernatant from A. pyogenes ATCC 19411 revealed one major point with protease activity at pH 5.2.

Actinomyces↗
PubMed2003

Polymerase chain reaction detection of Propionibacterium propionicus and Actinomyces radicidentis in primary and persistent endodontic infections.

OBJECTIVE: Propionibacterium propionicus and the recently described species Actinomyces radicidentis have been isolated from infections of endodontic origin; nevertheless, the possibility exists that their actual prevalence may have been underestimated by culture. The purpose of our study was to assess the occurrence of these 2 species in different types of endodontic infections by using the sensitive 16S rDNA-based nested polymerase chain reaction approach. STUDY DESIGN: To detect these 2 species, nested polymerase chain reaction was performed directly in samples taken from primary endodontic infections associated with asymptomatic periradicular lesions, acute apical periodontitis, or acute periradicular abscesses and in samples from patients in whom endodontic therapy had failed. DNA was extracted from the samples and initially amplified by using universal 16S rDNA primers. In the second round of amplification, the first polymerase chain reaction products were used to detect a specific 16S rDNA fragment of either P propionicus or A radicidentis. RESULTS: P propionicus was detected in 6/21 (29%) root canal samples from teeth with chronic periradicular lesions, in 5/10 (50%) cases diagnosed as acute apical periodontitis, and in 7/19 (37%) pus samples aspirated from acute periradicular abscesses. Overall, this species was found in 18/50 (36%) samples taken from primary endodontic infections. Of the root canal samples obtained from root-filled teeth with chronic periradicular lesions, P propionicus was detected in 7/12 (58%) cases. A radicidentis was detected in 1/21 (5%) root canal samples from teeth with chronic periradicular lesions and in 1/10 (10%) cases of acute apical periodontitis. No pus sample yielded this species. In general, A radicidentis was detected in 2/50 (4%) samples taken from primary endodontic infections and in 1/12 (8%) root canal samples taken from patients in whom endodontic treatment had failed. CONCLUSIONS: P propionicus was found in a relatively large number of patients with primary and persistent endodontic infections. This strengthens the assumption that this bacterial species is an endodontic pathogen associated with different forms of periradicular diseases. In contrast, A radicidentis was only occasionally detected in the patients examined. The role played by this species in endodontic infections remains to be clarified.

Actinomyces↗
PubMed1981

Potential salicylamide antiplaque agents: in vitro antibacterial activity against Actinomyces viscosus.

A series of 55 salicylamides, including 3,5-dibromo-, 5-n-alkyl-, and 5-n-acylsalicyloyl derivatives of various anilines, heterocyclic amines, benzylamines, and alkylamines, was synthesized and evaluated for in vitro antibacterial activity against Actinomyces viscosus, an adherent oral microorganism implicated in periodontal disease. The in vitro minimum inhibitory concentrations of 15 4'-bromosalicylanilides were found to correlate (r = 0.92) with estimated log D values. Several nonhalogenated salicylanilides, such as 5-n-hexyl- (40) and 5-n-decanoyl-4'-nitrosalicylanilide (47), were found to exhibit higher levels of in vitro antibacterial activity against a number of Actinomycetes than did tribromsalan (1) or fluorophene (2).

Actinomyces↗
PubMed2001

Actinomyces naeslundii fimbrial protein Orf977 shows similarity to a streptococcal adhesin.

The nucleotide sequence of the chromosomal DNA, upstream of Actinomyces naeslundii T14V fimbrial gene fimA, was determined. One open reading frame (orf977) encoding 977 amino acids was found, preceded by a gene homologous to elongation factor TU. Database searches revealed that Orf977 was homologous to CshA, a Streptococcus gordonii protein involved in cell adhesion. Previous studies had already determined two genes in the type 2 fimbrial gene cluster of A. naeslundii T14V: the structural subunit fimA, and orf365 with unknown function, followed by ribosomal genes. This study completes the type 2 fimbrial gene cluster sequence.

Actinomyces↗
PubMed2003

Induction of suppressor cells following mucosal presentation of Actinomyces viscosus in mice.

Mucosal presentation of Actinomyces viscosus results in antigen-specific systemic immune suppression, known as oral tolerance. The aim of the present study was to determine the mechanism by which this oral tolerance is induced. DBA/2 mice were gastrically immunized with A. viscosus. Serum, Peyer's patch (PP) and spleen cells were transferred to syngeneic recipients which were then systemically challenged with the sameiA. viscosus strain. To determine antigen-specificity of cells from gastrically immunized mice, recipients which received immune spleen cells were also challenged with Porphyromonas gingivalis. One week after the last systemic challenge, the delayed type hypersensitivity (DTH) response was determined by footpad swelling and the level of serum IgG, IgA and IgM antibodies to A. viscosus or P. gingivalis measured by an ELISA. No suppression of DTH response or of specific serum antibodies was found in recipients which received serum from gastrically immunized mice. Systemic immune suppression to A. viscosus was observed in recipients which had been transferred with PP cells obtained 2 days but not 4 and 6 days after gastric immunization with A. viscosus. Conversely, suppressed immune response could be seen in recipients transferred with spleen cells obtained 6 days after gastric immunization. The immune response to P. gingivalis remained unaltered in mice transferred with A. viscosus-gastrically immunized cells. The results of the present study suggest that oral tolerance induced by A. viscosus may be mediated by antigen-specific suppressor cells which originate in the PP and then migrate to the spleen.

Actinomyces viscosus↗
PubMed2003

Streptococci and Actinomyces induce antibodies which cross react with epithelial antigens in periodontitis.

Perturbation of epithelial structure is a prominent but poorly understood feature of the immunopathological response to bacterial antigens which characterizes the destructive lesion of periodontitis. Western analysis of sera from 22 patients with periodontitis detected multiple antigens in extracts of epithelial cells whereas sera from 12 periodontally healthy subjects displayed only trace reaction with epithelial antigens. To investigate a possible relationship between the bacterial flora adjacent to diseased sites and the presence of antibodies reactive with epithelium, subgingival plaque samples were taken from deep periodontal pockets and cultured anaerobically. Gram positive bacteria containing antigens cross-reactive with epithelial cells were reproducibly isolated by probing membrane colony-lifts with affinity-isolated (epithelium-specific) antibodies and identified by 16S rDNA sequence homology as streptococci (S. mitis, S. constellatus and two S. intermedius strains) and Actinomyces (A. georgiae, and A. sp. oral clone). Conversely, when serum from patients with periodontitis was absorbed with the captured bacterial species the number of epithelial antigens recognized was specifically reduced. It was concluded that development of cross-reactive antibodies related to these organisms may contribute to perturbation of the epithelial attachment to the tooth and the progression of periodontitis. These autoreactive antibodies could also be a contributing factor in other diseases affecting epithelia.

Actinomyces↗
PubMed1997

Isolation of Actinomyces viscosus strain GA: characteristics of its cellular biological retardant(s).

Actinomyces viscosus strain GA produces an exocellular biological retardant(s) that prevents certain vegetable plants from becoming overgrown. The biological retardant(s) was assayed using the etiolated wheat coleoptile assay, and fractionation of culture supernatant fluid resulted in a partial purification of the retardant(s). The biological retardant(s) was most active around pH 7 in the bioassay and when applied to sterile soil mixture. The biological retardant(s) was tentatively identified as a derivative of a rare hexose carbohydrate (but not an amino sugar) but an exact structure was not determined. In a sterilized synthetic soil system, the biological retardant(s) has an effect on tomato cultivars similar to that observed by the synthetic plant growth regulators Alar (succinic acid 2,2,-dimethylhydrazide) and Bonzi (paclobutrazol).

Actinomyces↗
PubMed2000

Actinomycosis of dogs caused by Actinomyces hordeovulneris.

Actinomyces hordeovulneris was isolated from the lesions of chronic pyogranulomatous pleuritis and pericarditis of one of three dogs showing similar symptoms. The parietal pleura and the pericardium were thickened and covered with fine short threads of angiofibroblastic tissue. About 500-1000 ml of reddish purulent exudate in the thorax of all three dogs contained large numbers of rice-grain-sized, soft, yellowish-white granules ("sulphur granules"). These granules had a central core of branching filaments of gram-positive bacteria embedded in thick granulation tissue. The parietal pleura, the mediastinal pleura and the pericardium were infiltrated mainly with neutrophils, and to a lesser extent with lymphocytes and plasma cells. A small number of eosinophils and giant cells was also observed. Large numbers of pyogranulomas embedded in the granulation tissue were composed of a core of necrotized granulation tissue, mixed with clusters of gram-positive branching bacteria, surrounded by an area of intact and degenerating neutrophils and lymphocytes. Bacteria were detected in the lesions by Brown-Brenn staining and were isolated from one of the affected animals. The isolated bacteria were identified as A. hordeovulneris. This was the first isolation of A. hordeovulneris in Hungary.

Actinomyces↗
PubMed2001

[Acute retrocecal appendicitis caused by an Actinomyces israelii mixed infection].

We report the rare case of a retrocecal appendicitis in an adult caused by an Actinomyces israelii mixed infection. Suspecting an acute appendicitis the explorative laparotomy was performed. Appendectomy with extensive drainage of the abscess and subsequent high-dose penicillin therapy over several months were the definitive treatment, resulting in complete healing. Special features of clinical symptomatology and problems concerning diagnosis and differential diagnosis are discussed.

Actinomyces↗
PubMed2003

Effect of sustained-release chlorhexidine varnish on Streptococcus mutans and Actinomyces viscosus in orthodontic patients.

This study evaluated the effect of sustained-release chlorhexidine varnish on orthodontic patients. Ten children, ages 10 to 16 years, participated. Bacterial levels of Streptococcus mutans and Actinomyces viscosus and total counts were evaluated in sputum samples. These counts were evaluated at 4 stages: before orthodontic treatment, at least 2 weeks after bonding of the brackets, 1 week after application of chlorhexidine varnish, and 3 weeks after application of chlorhexidine varnish. Increases in bacterial levels of S mutans and in the total bacterial count were detected after the brackets were bonded. One week after the sustained-release chlorhexidine varnish was applied, a significant decrease of total bacterial levels and S mutans was observed. This decrease persisted for 3 weeks after the first application. No significant change in A viscosus levels occurred during that period. The results provide additional evidence that sustained-release chlorhexidine varnish decreases S mutans levels in orthodontic patients with fixed appliances and therefore might be useful in preventing caries lesions.

Actinomyces viscosus↗