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At least 19 recordsLinked to original sources
PubMed1979

Production of beta-lactamase by non-streptomyces Actinomycetales.

Supernatants and whole cells from fermentation broths of Micromonospora, Nocardia, Oerskovia, and other genera of the Actinomycetales were examined for the presence of beta-lactamase activity by using the chromogenic cephalosporin 87/312. Nearly 60% of the 250 isolates examined produced detectable levels of beta-lactamase. All enzyme preparations were active over a range of pH values from 6.5 to 8.2, with maximum activity occurring between 7.0 and 7.8. The preparations varied in their stability at 60 degrees C. An examination of selected enzyme preparations revealed a similarity between substrate specificities of the non-Streptomyces Actinomycetales and gram-negative-bacterial beta-lactamases.

Actinomycetales↗
PubMed1975

Immunophyletic relationships between actinomycetales and eubacteriales determined by examinations of their cytoplasmic antigens.

Cytoplasms obtained from a total of 205 different strains of Actinomycetales, Eubacteriales, Lower Fungi, and Protozoa were examined against selected anti-cytoplasm antisera using the immunodiffusion and counterimmunoelectrophoresis procedures. Immunological relationships between the different genera have been revealed and, in respect to Eubacteriales, the possible immunophyletic determinants have been discerned. Cytoplasms of Enterobacter, Clostridium, Staphylococcus, and Diplococcus were found to retain the significant linkage determinants between large groups of Eubacteriales and Actinomycetales. Evolutionary implications of the findings are discussed.

Actinomycetales↗
PubMed1975

Actinomycetales from corn.

Mesophilic Actinomycetales were isolated from whole corn, brewers grits, and break flour received from three different mills. In addition, strains were isolated from high-moisture (27 per cent) field corn; high-moisture, silo-stored corn (untreated); and high-moisture corn treated with ammonia, ammonium isobutyrate, or propionic-acetic acid. According to standard techniques, 139 strains were extensively characterized and 207 additional strains were partially characterized. On the basis of these characterizations, the streptomycete strains were identified by both the systems of Pridham et al. and Hütter because these systems are rapid and accurate. In general, only Streptomyces griseus (Krainsky) Waksman and Henrici was isolated from high-moisture whole corn (treated or untreated) except from grain exposed to ammonium isobutyrate. Strains isolated from high-moisture corn subjected to that treatment represented both S. griseus and S. albus (Rossi Doria) Waksman and Henrici. The strains isolated from corn and corn products from the three mills were identified with a number of streptomycete species. Of all Actinomycetales isolated, only three were not streptomycetes--two from brewer's grits and one from break flour.

Actinomycetales↗
PubMedDate not supplied

[Comparative characteristics of the ability to coagulate milk in different representatives of the order Actinomycetales].

The ability to clot milk was studied among 482 cultures of Actinomycetales. The highest activity was manifested by thermophilic actinomycetes, the next come globisporous, white, and gray groups of the genus Actinomyces. Cultures belonging to the genera Mycobacterium and Mycococcus did not clot milk. The ability to clot milk can be used as an additional taxonomic index while studying ray fungi.

Actinomyces↗
PubMed1979

[Actinomycetales in cutaneous pathology].

After discussing the classification of the Actinomycetales, the authors give a detailed description of the epidemiology and particularly of the clinical features of cutaneous diseases induced by genera such as Actinomyces, Norcardia and Streptomyces. Histopathological and immunological studies, together with laboratory and differential diagnostics, are also examined. In the last section, present therapeutic treatments are briefly outlined.

Actinomyces↗
PubMedDate not supplied

[Rapid selection of microorganisms belonging to the genus Pseudomonas and the order Actinomycetales and producing exocellular lecithinases].

A rapid and simple method is suggested for primary selection of microorganisms producing exocellular lecithinases; the method is based on diffusion of the enzyme into agar containing lecithin. Among 55 studied cultures belonging to the genus Pseudomonas 18 cultures were active. Among 326 studied strains belonging to the order Actinomycetales, 7 strains were active and their level of lecithinase biosynthesis was much higher.

Actinomycetales↗
PubMed1979

Studies on Actinomycetales producing antibiotics only on agar culture. I. Screening, taxonomy and morphology-productivity relationship of Streptomyces halstedii, strain SF-1993.

Soil Actinomycetales that produce antibiotics during growth on agar but not in submerged culture were searched for and about 25 strains were obtained. One of these, Streptomyces halstedii, strain SF-1993, which produces an antibiotic designated SF-1993 was studied taxonomically and morphologically. The antibiotic-productivity of strain SF-1993 was correlated with mycelial morphology. The vegetative mycelium was filamentous in antibiotic-producing agar cultures, but fragmented in non-producing submerged cultures. By maintaining submerged cells filamentous, production of antibiotic in the submerged fermentations was accomplished. Filamentation was maintained by the use of diluted media or non-fragmented mutant substrains.

Agar↗
PubMed1979

Glaucescin, a bacteriocin-like substance from Streptomyces glaucescens.

Streptomyces glaucescens ETH 22794 produced a variety of antibiotic substances. Besides low molecular weight antibiotics like hydroxystreptomycin and the tetracenomycins, this strain excreted glaucescin, a high molecular weight product with bacteriocin-like properties. In plate tests the antagonism of glaucescin against Streptomyces canadiensis was masked by the large inhibition zone caused by the tetracenomycins. Glaucescin activity was revealed when a tetracenomycin-resistant mutant of S. canadiensis NRRL 3155 was used as an indicator. Glaucesin was produced on complex and minimal solid and liquid media. It was not inducible by mitomycin C. The killing activity of glaucescin was thermolabile and resistant to DNAase, RNAase, various proteinases, and lipase. Its apparent molecular weight was estimated as 196000 by gel filtration and glycerol gradient centrifugation. Glaucescin preferentially killed outgrowing spores of S. canadiensis. Resting spores and mycelium were considerably less sensitive to the inhibitor, and adsorption of glaucescin by S. canadiensis paralleled sensitivity. The activity spectrum of the bacteriocin was restricted to spore-forming Actinomycetales. Non spore-forming nocardiae and a variety of Gram-positive and Gram-negative bacteria were resistant to glaucescin.

Actinomycetales↗
PubMed1977

Bacterial parasite of a plant nematode: morphology and ultrastructure.

The life cycle of a bacterial endoparasite of the plant-parasitic nematode Meloidogyne incognita was examined by scanning and transmission electron microscopy. The infective stage begins with the attachment of an endospore to the surface of the nematode. A germ tube then penetrates the cuticle, and mycelil colonies form in the pseudocoelom. Sporulation is initiated when terminal cells of the mycelium enlarge to form sporangia. A septum within each sporangium divides the forespore from the basal or parasporal portion of the cell. The forespore becomes enclosed by several laminar coats. The parasporal cell remains attached to the forespore and forms the parasporal microfibers. After the newly formed spores are released into the soil, these microfibers apparently enable a mature spore to attach to the nematode. These results indicate that the endoparasite is a procaryotic organism having structural features that are more common to members of Actinomycetales and to the bacterium Pasteuria ramosa than to the sporozoans or to the family Bacillaceae, as previous investigatios have concluded.

Actinomycetales↗
PubMed1977

Morphology of colony variants of the rough form of Dermatophilus spp.

A technique is described for the preparation of intact colonies of Dermatophilus and their study under the scanning electron microscope. Using this technique with 38 strains of the organism it is possible to describe for the first time the patterns of colony morphology and to study the relationship of hyphae, cocci and zoospores in situ. Colonies were found to possess both vegetative and aerial hyphae. The various patterns of mycelial activity and structure that were seen raised serious doubts about the previous concepts of the mode of propagation and thus the classification of Dermatophilus within the Actinomycetales.

Actinomycetales↗
PubMed1979

Demonstration of tuberculostearic acid in sputum from patients with pulmonary tuberculosis by selected ion monitoring.

Selected ion monitoring was used to detect tuberculostearic acid (10-methyloctadecanoic acid) in sputum from patients with pulmonary tuberculosis. The specimens were autoclaved, lyophilized, extracted, and methanolysed before being subjected to thin-layer chromatography and injected into the gas chromatograph/mass spectrometer. Tuberculostearic acid could be detected in five of six tuberculous sputum specimens containing acid-fast rods detectable by light microscopy of Ziehl-Neelsen stained smears. After the sputum specimens had been cultured for five days on Löwenstein-Jensen medium, when still no colonies could be observed visually, the presence of tuberculostearic acid was demonstrated in all six cases of tuberculosis. In corresponding analyses of sputum from eight patients with non-tuberculous pneumonia, tuberculostearic acid was not found. This fatty acid, the presence of which was also demonstrated in cultures of various mycobacterial and nocardial species, is characteristic of organisms of the order Actinomycetales. The demonstration of tuberculostearic acid in sputum specimens may constitute a rapid and sensitive way of diagnosing pulmonary tuberculosis.

Chromatography, Gas↗
PubMed1976

[Pulmonary reactions to non-infective antigenic contaminants].

There are different categories of non-infectious antigenic contaminants capable of provoking pulmonary reactions: thermophilic actinomycetales, fungi, vegetable particles, protein antigens, arthropods, drugs; their identification is based on their isolation, culture, and the study of their biochemical composition. The pulmonary reactions depend on the size and number of antigenic particles inhaled and by the underlying background. The immunological mechanisms brought into play a complex Arthus's phenomenon: in addition to the IgGs, the IgEs and the different factors of complement intervene; the recent acquisitions of immunomorphology enable better comprehension of the histogenesis of the pulmonary granuloma. The diagnosis of extrinsic allergic alveolitis is founded on well defined criteria of clinical, radiological, respiratory functional, immunological and histophthological order. These conditions are met with in agricultural, industrial and urban environments or are related to iatrogenic diseases. Many problems still remain obscure with regards to the pathogenesis and integration within the framework of immunological pneumonia of various conditions, and especially certain sarcoidosis.

Antibodies↗
PubMed1978

The effect of prednisolone trimethylacetate on the pathogenicity of Dermatophilus congolensis to white mice.

Albino mice were successfully infected intravenously, subcutaneously, intraperitoneally and on the intact and scarified skin with Dermatophilus congolensis. Various gross lesions were observed. Large subcutaneous nodules were produced in mice that were injected subcutaneously. Lesions involving the internal organs were obtained in mice that had been injected intravenously and intraperitoneally in addition to microabsessation and scab formation on the tails of those that were injected intravenously. The application of D. congolensis on scarified skin resulted in scab formation covering the whole area while its application on non-scarified skin produced isolated lesions. The organism was isolated in pure culture from exudate, pus and scab material obtained from lesions. Severe histopathological changes were noted in sections prepared from the lesions. Premedication of mice with prednisolone trimethylacetate increased the severity of the experimentally induced lesions.

Actinomycetales↗