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D P Shraer

Publications and source records attributed to D P Shraer.

13 recordsLinked to original sources
PubMed1978

[Elimination of penicillinase plasmids by the new acridine derivative, Dimer].

The possibility of eliminating the drug resistance determinants in penicillinase-producing staphylococci under the effect of an acridine "dimer", synthesized by French scientists was studied. Comparison of the eliminating activity of a number of acridine compounds, such as acrichin, acriflavine, proflavine and "dimer" showed that the new derivative of acridine as well as the other acridines used in the experiments induced elimination of the penicillinase plasmids when used in the sublethal concentrations.

Acridines↗
PubMed1978

[Local experimental infection caused by S. epidermidis sensitive to penicillin under the action of the antibiotic and acridines].

S. epidermidis D-5/48, D-5/240, and S. aureus 209 P caused a local infectious process with an analogous course in intrascrotal infection of male albino mice; this process was characterized by the changes of the relative weight coefficient of the affected tissues, positive staphylococcus culture, and exudative inflammation. This confirmed the role of epidermal coagulase-negative staphylococci in the infectious pathology. Benzylpenicillin treatment of local staphylococcus infection proved to be ineffective, although the staphylococcus strains used for the infection were sensitive to this antibiotic. This treatment led to the selection of the antibiotic-resistant forms of the microorganisms and to the aggravation of the infectious process, suggesting greater virulence of the antibiotic-resistant strains. The minimal suppressive acridines concentrations prevented the development of penicillin resistance and selection of resistant staphylococci, increased the therapeutic efficacy of this antibiotic.

Acridines↗
PubMed1977

[Staphylococcal plasmacoagulase. III. Use of thrombelastography to study the properties of extracellular staphylocoagulase].

A method of thromboelastography was applied to the study of the influence of supernatents of the S. aureus and S. epidermidis culture fluid on the process of blood coagulation. S. aureus No. 209 P, No. 8325-1 strains and mutants of the No. 209 P strain, resistant to proflavin induced a distinct shortening of the reaction time. In using S. epidermidis (strains D5/240 and D-5/48) and also in control experiments (plasma and medium) no shortening of the reaction period was observed. The data obtained permitted to recommend the use of thromboelastographic method for the purpose of detection of coagulase-positive staphylococcus strains and for the assessment of relative staphylocoagulase activity.

Coagulase↗
PubMed1977

[Spontaneous mutants of S. aureus 209 P resistant to 3,6-diaminoacridines].

Spontaneous mutants of S. aureus 209 P resistant to proflavine sulphate and possessing cross resistance to acriflavine and acridine yellow were isolated. Sensitivity of these mutants to acridine orange, acridines No. 40 and 56 remained unchanged. The phage type and the indices of potential pathogenicity of proflavine-resistant mutants coincided with the corresponding S. aureus 209 P indices.

Acridines↗
PubMed1976

[Modified nephelometric method of determining the activity of extracellular staphylococcal plasmocoagulase].

The nephelometric method of the quantitative determination of plasmocoagulase was modified. The medium for growing staphylococci and the composition of the "substrate" were elaborated. The necessity of recalculation of the absolute coagulase activity into specific activity with the consideration to the microbial cell count in the suspension from which the supernatent containing the enzyme was obtained. The greatest plasmocoagulase activity was revealed in the 6- and the 24-hour cultures of Staph. aureus. The optimal time of incubation of the reactive medium (enzyme-substrate) was 4 hours.

Coagulase↗
PubMed1976

[Production of extracellular plasmocoagulase in staphylococcus aureus exposed to 3,6-diaminoacridines].

A modified quantitative nephelometric method was used. It was shown that production of extracellular plasmocoagulase was depressed in the development of acridine-sensitive and acridine-resistant cultures of Staph. aureus in the fluid nutrient medium containing 3,6-diaminoacridines: acriflavine, proflavine, acridine yellow, acridine orange, acridine No. 40 and acridine No. 56; 3,6-diaminoacridines failed to lead to noncompetitive inhibition of staphylococcus plasmocoagulase. A disturbance of the regulation of the enzyme exit into the external environment can serve as the cause of depression of the extracellular plasmocoagulase production by Staph. aureus.

Acridines↗
PubMed1975

[Resistance of the Staphylococcus aureus isolated from patients operated on for cardiovascular diseases to penicillins, cephalosporins and the salts of heavy metals, their lysogenicity and phagotype].

The analysis of the results obtained on the study of 55 strains of Staph. aureus isolated from purulent excretion in the patients operated under conditions of artificial blood circulation provided a conclusion that most of the clinical staphylococcal cultures were highly resistant to the beta-lactamase sensitive antibiotics. It was supposed that the above strains possessed penicillinase plasmids, since all the cultures tested had penicillinase activity and were resistant to benzylpenicillin, the resistance exceeding 1.0 Unit/ml, in 70 percent of the cultures these properties were complemented with resistance to heavy metals salts and mercuric chloride. These cultures possessing penicillinase plasmids belonged mainly to the phage group, III and were polylysogenic.

Bacteriophage Typing↗
PubMed1975

[Specific and nonspecific factors that influence the transduction of genetic determinants for penicillinase activity and pathogenicity in Staphylococcus aureus. III. The prevention of the transduction of penicillinase determinants by acridine derivatives].

In comparing the antitransducing activity of the acridine derivatives there was revealed a relationship between their chemical structure (the degree of substitution of position 9), the capacity to depress the lytic activity of staphylophages and the action in respect to the transducing particles of the donor lysate.

Acridines↗
PubMed1975

[The action of acridine derivatives on penicillinase production by staphylococcus aureus].

A study was made of a possibility of inhibition of biosynthesis of penicillinase in Staph. aureus by acridine derivatives. Acetone preparations of penicillinase were obtained from the cultures of staphylococcus strains 16/160 and 8325 (p11(147) pen 1220) grown in the presence of various subbacterial concentrations of acridine derivatives. The activity of the enzyme was studied in experiment and control by the microiodometric method. Acriflavine and proflavine inhibited the penicillinase biosynthesis from the 4th hour of growth, and rivanol, acrichine, acridines No. 27 and 37--from the 12th hour of the culture growth.

Acridines↗
PubMed1975

[Factors influencing transduction of genetic determinants of penicillinase activity and pathogenicity in staphylococcus aureua. II. Antiphage activity of acridine derivatives].

Acridine dyes examined earlier (acrichine, acridine orange, proflavine and rivanol) and newly-synthesized preparations (acridines No. No. 37--40) were studied in the capacity of nonspecific agents influencing the lytic cycle in development of staphylococcus phages. Acrichine and acridine No. 37 failed to prevent lysis of the indicator staphylococcus cultures (strains 16/160 and 8325) by bacteriophages; proflavine, rivanol, acridines No. No. 39--40 produced a marked inhibitory effect; acridine orange and acridine No. 38 inhibited the staphylococcus lysis completely. Some preparations could be used to investigate the transduction phenomenon.

Acridines↗