Identification of some clinically significant actinomycetes.

Early recognition of infections caused by actinomycetes tend to be highly dependent on at least a tentative diagnosis derived from microbiological tests, since the clinical symptoms can be difficult to interpret. Reliable identification of clinically significant actinomycetes depends upon the application of taxonomic techniques that are not yet widely used in clinical laboratories. The value of rapid enzyme, chemical and molecular fingerprinting techniques is exemplified by their application to the identification of representatives of clinically significant actinomycete taxa.

Ribonucleotide reductase in Bacillus subtilis--evidence for a Mn-dependent enzyme.

The reduction of 2'-ribonucleotides to 2'-deoxyribonucleotides, a unique step in DNA formation, is catalyzed by ribonucleotide reductase (RRase), an allosterically regulated, cell cycle-dependent enzyme. This work reports a reversible impairment of DNA formation and ribonucleotide reduction upon manganese depletion in Bacillus subtilis demonstrated through in vivo labeling with necleic acid precursors and enzyme assays with ether-permeabilized cells. No deoxyadenosylcobalamin-dependent reduction of ribonucleotides was detected in the cytosol, and the properties of a partially purified enzyme fraction, i.e., sensitivity towards EDTA and hydroxyurea (HU), indicated a metal-dependent type of RRase. The enzyme was enriched by gel filtration on Superose 12 from glycerol- or fumarate-grown cells and submitted to Q-band electron paramagnetic resonance (EPR) spectroscopy for further characterization of the metal center. A distinct Mn(II) signal was obtained in both preparations characteristic of a protein-bound mangaenese in a mononuclear metal center with axial symmetry. The intensity of this Mn signal was not affected by addition of the radical scavenger HU (10 mM) but reduced in the presence of 2.5 mM EDTA. On the basis of these results, we suggest that Bacillus subtilis has a Mn-dependent ribonucleotide reductase.

[The use of batumin-containing disks for the rapid identification of staphylococci]. / Ispol'zovanie diskov s batuminom dlia ékspress-identifikatsii stafilokokkov.

The study of 467 microbial strains obtained from collections and from clinical sources revealed that microorganisms of the genus Staphylococcus were highly sensitive to batumin, a new antibiotic obtained from bacteria of the genus Pseudomonas. 378 strains of 15 Staphylococcus species proved to be highly sensitive to the diagnostic preparation "Diastaph", developed on the basis of batumin (antibiotic-impregnated discs); After 18-hour incubation the diameter of the growth inhibition zones on agar-containing culture media was 18-38 mm. Strains belonging to the genera Micrococcus, Dermacoccus, Kocuria and Kytococcus, as well as the tested representatives of other taxa (Planococcus, Streptococcus, Corynebacterium, Acinetobacter, Pseudomonas, Neisseria, the representatives of all tested genera of the family Enterobacteriaceae, fungi of the genus Candida) were insensitive to the diagnosticum. "Diastaph" permits not only the rapid identification of staphylococci pure cultures, but also the determination of their presence in association with other microbial species directly in pathological material, which makes it possible to recommend this diagnostic preparation for use in medical, veterinary and sanitary microbiology.

[Use of an immunodiffusion analysis method in micrococcus species determination]. / Ispol'zovanie metoda immunodiffuzionnogo analiza v vidovoi differentsiatsii mikrokokkov.

Eight species of the genus Micrococcus were studied in details for their antigenic specificities with the aid of the created bank of specific polyclonal antisera to the type strains of Micrococcus Cohn 1872--M. luteus CCM 169, M. varians CCM 884, M. roseus CCM 679 and M. nishinomiyaensis CCM 2140. Immunochemical analysis of 146 strains isolated from various natural and industrial substrata, as well as of 31 collection strains allowed us to reveal antigenic relatedness and distinctions between studied cultures and to accomplish taxonomic distribution of various Micrococcus species. By the immunoduffusion analysis the intraspecific antigenic relationship of M. roseus and M. varians was found, as well as significant antigenic heterogeneity of M. luteus. The results of antigenic analysis of micrococci may be used in the collection work and for the express-diagnostics of these microorganisms.

[Amino acid composition of peptidoglycans isolated from cells of Coryneform bacteria by various methods]. / Aminokislotnyi sostav peptidoglikanov, vydelennykh razlichnymi metodami iz kletok korinepodobnykh bakterii.

A comparative study has revealed the identity of the amino acid composition of the peptide part of peptidoglycans obtained from the intact cells (the first method) and of the amino acid composition of peptidoglycans isolated from cell walls (the second method). This evidences for the possibility of using the first method when determining types of peptidoglycans for diagnosis of the coryneform bacteria genera.