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At least 667 records · Page 37Linked to original sources
PubMed1989

In vitro function of bovine neutrophils against Actinomyces pyogenes.

Factors that influenced the in vitro bactericidal activity of bovine neutrophils against Actinomyces pyogenes were investigated. Neutrophils and serum from 2 clinically normal donor cows were incubated with bacteria for 2 hours. To determine bactericidal activity, colony-forming units were counted after a 48-hour incubation on blood agar plates. Microscopic examination indicated that in the presence of serum, bacteria were cell associated after incubation, whereas when serum was replaced by medium, bacteria were not cell associated. Bactericidal activity of neutrophils was similar whether the sera were heat-treated at 56 C for 30 minutes or were not heated. Heating the serum at 65 C for 30 minutes significantly (P less than 0.001) reduced bactericidal activity. Bactericidal activity decreased (P less than 0.001) as serum concentration (less than 10%) decreased. More than 80% of the bacteria were killed within the 40 minutes of incubation. The opsonizing capacity of serum varied significantly (P less than 0.01) among 12 cows. Similarly, neutrophil bactericidal activity (by cow) was affected significantly (P less than 0.001). Preincubation of serum with A pyogenes significantly (P less than 0.001) reduced the opsonizing ability of the serum. Culture filtrate of A pyogenes was not chemotactic for neutrophils in vitro.

Actinomyces↗
PubMedDate not supplied

Association of amoebae and actinomyces in an intrauterine contraceptive device user.

A patient wearing an intrauterine contraceptive device (IUD) was diagnosed as being colonized by Actinomyces and amoebae by examination of a routine Papanicolaou smear. The patient received vaginal treatment with metronidazole, which temporarily eliminated the protozoa; however, it was necessary to remove the IUD to definitively eradicate the microorganisms. Follow-up Papanicolaou smears taken after removal of the IUD have been normal and free of both microorganisms.

Actinomyces↗
PubMed1989

Specific antibody in milk whey and phagocytosis of Actinomyces pyogenes by neutrophils in vitro.

Milk samples were collected from 21 non-pregnant cows to study the ability of milk whey to support in vitro bactericidal activity of neutrophils against Actinomyces pyogenes. Significant differences (P less than 0.01) existed in opsonising ability of milk whey samples from individual cows. Antibody titres to A pyogenes in milk whey were determined using an enzyme linked immunosorbent assay. Bactericidal activity of neutrophils incubated with milk whey was positively correlated (P less than 0.05) with titres of IgG2 and IgM antibodies but not with IgG1 or IgA antibodies.

Actinomyces↗
PubMed1977

Are Actinomyces viscosus antigens B cell mitogens?

An extracellular heteroglycan (ECHG) and a sonicated cell supernatant (SCS) of Actinomyces viscosus Ny 1 induced strong lymphocyte proliferation. This was shown with spleen and thoracic duct cells form germfree rats and confirmed with cells from conventional "nude" mouse spleens. Spleen cells developed direct plaque-forming cells against densely coupled TNP-SRBC. The mitogenic property of ECHG was diminished considerably after mild alkaline hydrolysis for lymphocytes form rat spleens and was totally abolished for cells from "nude" mouse spleens. These results suggest that ECHG and SCS have B cell mitogenicity.

Actinomyces↗
PubMedDate not supplied

[Preparation of extracellular ribonuclease form Actinomyces rimosus 994].

By sequential acid treatment, gel filtration and KM-cellulose sorption a 18--20-fold purified preparation of ribonuclease with a yield of 50--60% was obtained from the culture liquid filtrate of Actinomyces rimosus 994. The preparation had a high specific activity of 450,000--600,000 units/mg protein, contained 85--98% protein, insignificant amounts of carbohydrates and hydroxytetracycline, and no quantities of DNase, phosphomonoesterases, phosphodiesterase or proteases. In RNA degradation (preparation of the total yeast RNA of the Sigma Co.) optimal results were obtained at 50 degrees C and pH 7.0--7.2 in phosphate buffer and 7.6--8.0 IN Tris-HCl buffer. The preparation was stable at high temperatures (80--100 degrees) in the wide pH range and during storage in the lyophilized form and in buffer solutions. RNase effect was inhibited by zinc, copper, iron and cobalt cations and activated by beta-mercaptoethanol, citrate and EDTA. Protamine sulphate and urea in low concentrations (0.01% and 1--4 M, respectively) accelerated and in high concentrations (1% and 8 M, respectively) terminated the enzyme reaction. With respect to many properties RNase from Act. rimosus 994 was similar to extracellular RNases, produced by other actinomycetes and fungi.

Actinomyces↗
PubMedDate not supplied

[Comparative study of different variants of Actinomyces roseoflavus producing the polyene antibiotic roseofungin].

The respiration chain in the membranes of whole Actinomyces roseoflavus (var. roseofungini) cells from the parent and secondary cultures is sensitive to KCN, non-sensitive to Triton X-100 treatment removing the antibiotic roseofungin from the cells, and has a very high for the bacteria respiration control. When the cells are in contact with atomic tritium at the temperature of liquid nitrogen, roseofungin is tritiated and binds to A. roseoflavus isolated membranes and whole cells, mostly to those of the parent culture as compared to the secondary culture. A fraction of membranes which lost NADH dehydrogenase in the course++ of purification was isolated from the cells disintegrated in the frozen state.

Actinomyces↗
PubMed1988

Septic arthritis and osteomyelitis in a bovine digit: a mixed infection of Actinomyces pyogenes and Fusobacterium necrophorum.

A 4-year-old beefmaster cow was examined for a left hind leg lateral claw lameness due to septic arthritis of the distal interphalangeal joint and associated osteomyelitis of the second and third phalanges. Actinomyces pyogenes and Fusobacterium necrophorum, which have been demonstrated previously to act synergistically in ovine heel abscesses, were isolated from the affected digit. A claw amputation was performed because of the advanced destructive nature of the lesion.

Actinomyces↗
PubMed1977

[Actinomyces odontolyticus, first study in France].

The authors report the detailed study of a strain of Actinomyces odontolyticus isolated from a pleural liquid. Gas-liquid chromatography can specify the biochemistral metabolism of the germ and set off an endocellular lipidolytic activity.

Actinomyces↗
PubMed1978

Plaque formation in vitro by Actinomyces viscosus in the presence of Streptococcus sanguis or Streptococcus mutans.

Actinomyces viscosus, growing on a tooth in the presence of sucrose, slowly produced a loosely-attached plaque, the pH being 6.1 after 120 h. When the tooth was inoculated simultaneously with A. viscosus and either Streptococcus sanguis or Streptococcus mutans, firmly-adherent plaque was quickly formed and the pH fell below 5 after 33 h with the former Streptococcus and 24 h with the latter. A. viscosus disappeared from each mixed plaque by 120 h.

Actinomyces↗
PubMedDate not supplied

[Influence of cultivation conditions on the synthesis of trypsin inhibitor in the submerged culture of Actinomyces janthinus 118].

The influence of mass exchange and cultivation temperature on the synthesis of trypsin inhibitor in the submerged culture of Actinomyces janthinus was studied. Mass exchange parameters of the fermenter varied from 0.72 to 3.7 g O2 l/hr without oxygen limitations, and cultivation temperature ranged from 25 to 34 degrees C. The growth pattern, dynamics of substrate consumption and synthesis of trypsin inhibitor by the culture of Act. janthinus were shown to depend on mass exchange and cultivation temperature. With an increase in mass exchange the inhibitory activity reached maximum earlier but did not rise in its absolute value. With a temperature increase the inhibitory activity grew by 65%.

Actinomyces↗
PubMedDate not supplied

[Isolation and characterization of hemagglutinin from the stock culture of Actinomyces streptomycini str. 32-12].

From the culture fluid of Actinomyces streptomycini streptomycin was extracted and then hemagglutinin, a biologically active substance, was isolated. The isolation included ethanol fractionation, sulfate ammonium protein precipitation, elimination of contaminating components via centrifugation, dialysis and subsequent lyophilization. The resultant hemagglutinin showed activity towards animal and human erythrocytes, and blast-transforming and mitogenic activity towards human lymphocytes.

Actinomyces↗
PubMedDate not supplied

[Decomposition of human blood cholesterol by the enzyme from Actinomyces lavendulae].

In vitro experiments with enzymic decomposition of cholesterol contained in the human blood were carried out. The enzyme was obtained from the mycelium of Actinomyces lavendulae. As a result of incubation of blood samples in the presence of the enzyme at 37 degrees, the cholesterol content decreased and reached 30--43% of the initial value within 2 hours. The enzyme showed its specific effect only upon free cholesterol but not on its esters.

Actinomyces↗
PubMed1976

[L-valine transport by the actinomycete Actinomyces species 26-115, the producer of actinomycin C].

Transport of L-valine by Actinomyces species 26-115, an organism producing actinomycin C depended on L-valine concentration in the medium and temperature and required a source of intrinsic energy. Km for L-valine transport was 3.5.10(-6)--6.0.10(-6) M. It somewhat differed from experiment to experiment. The above system transported also other neutral amino acids. L-isoleucine was a competing inhibitor of L-valine transport. The transport of L-valine was stereospecific. The activity of the transport system was regulated by the intracellular content of L-valine. Probably because of this the amino acid transport depended on the culture age, so far as the level of free valine in the mycelium at various stages of development was different.

Actinomyces↗
PubMedDate not supplied

[The effect of beta-ionine on biosynthesis of carotenes by Actinomyces chrysomallus var. carotenoides].

Biosynthesis of carotenoids by a growing culture of Actinomyces chrysomallus var. carotenoides is totally inhibited by beta-ionone added at different concentrations, at various time of the cultural growth, and in various combinations with oil. The inhibition of carotenoid synthesis by beta-ionone is of a specific character since the biomass growth under the same conditions does not increase.

Actinomyces↗
PubMed1981

Detection and localization of a lectin on Actinomyces viscosus T14V by monoclonal antibodies.

A cell-associated lectin activity that mediates lactose-inhibitable adherence of Actinomyces viscosus T14V has been localized to a specific population of fimbriae by the use of monoclonal antibodies. Nine monoclonal antibodies were produced that reacted with only 1 of 2 immunoelectrophoretically distinct fimbrial components on T14V. The fibrillar morphology of this component was revealed by the immunoelectronmicroscopic examination of bacteria incubated with the monoclonal antibodies. The lectin activity associated with these structures was detected when isolated fimbriae were cross-linked with monoclonal antibodies to form immune complexes with agglutination activity for neuraminidase-treated human erythrocytes, a reaction that was inhibited by lactose. Although the 9 monoclonal antibodies differed in their fine specificities, they reacted only with strains of A. viscosus and A. naeslundii that exhibited lactose-inhibitable adherence. These findings indicate that the lectin activity common to these bacteria resides on fimbriae that are antigenically related to those of T14V.

Actinomyces↗
PubMed1981

[Characteristics of the active and inactive variants of Actinomyces sp. 26-115, a producer of actinomycin C].

Two natural variants, i.e. No. 1 and No. 2, not producing actinomycin were isolated from cultures of the actinomycin C-producing organism Actinomyces sp. 26-115. Variant No. 1 differed from the active variant by the growth dynamics and colony morphology. Variant No. 2 was close to the active variant by the growth dynamics. It was shown with electron microscopy that the cells of variant No. 1 differed from those of the active variant in the number and form of the mycelial septa, more even and compact structure of the cell walls and higher sensitivity to actinomycin. Still, they were more stable to the effect of lysozyme and ultrasound. The cell walls of the inactive variant No. 1 gradually lost teichoic acid during development, while the loss of peptidoglycan was observed only on transfer to the stationary phase. The cell walls of the active variant lost teichoic acid and peptidoglycan at the same time on transfer to the stationary phase. Peptidoglycans of both variants contained diaminopimelic acid (the configuration of which was not determined) and glycine (1:1) as differentiating amino acids. The two adjacent tetrapeptides were joined with one glycine radical. The peptidoglycan peptide chains of both variants contained muramic, glutamic and diaminopimelic acids and alanine (1:1:1:2). The peptidoglycans of the inactive variant No. 1 contained in addition valine and isoleucine. However, it is hardly probable that they are contained by the peptidoglycan peptide chains.

Actinomyces↗
PubMed1981

[Membrane proteins of active and inactive variants of Actinomyces sp. 26-115, a producer of actinomycin C].

Some properties of the membrane proteins of Actinomyces sp. 26-115, i. e. its active variant and a variant not producing actinomycin C were studied comparatively. The membrane proteins of both variants of all ages tested represented a heterogenous fraction including about 30 protein components with a molecular mass of 17000 to 500000. There were differences in the protein component composition of the active and inactive variants. The membrane proteins of the active variant contained much more disulfide bonds than those of the inactive variant. It was shown in the model experiments on the protein binding of the phospholipid-lecithin membranes that the membrane proteins of the active variant bound higher amounts of lecithin during the whole developmental cycle than those of the inactive variant. It is suggested that the membrane proteins of the active variant had conformation differences as compared to those of the inactive variant.

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