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V S Zueva

Publications and source records attributed to V S Zueva.

At least 55 records · Page 3Linked to original sources
PubMed1978

[Drug resistance stability in staphylococci under different conditions. The mechanism of the recovery of streptomycin sensitivity of a staphylococcal population in patients 7 months after hospital discharge].

A method for analysis of antibiotic sensitivity restoration in staphylococcal populations in humans is described. The mechanism of streptomycin sensitivity restoration in staphylococcal populations on the nasal mucosa of 59 patients 7 months after discharging from surgical stationary was studied. Quantitative estimates for loss of superinfecting streptomycin-resistant staphylococci, initial streptomycin-resistant staphylococci and resistance determinants by the initial streptomycin-resistant staphylococci are presented.

Drug Resistance, Microbial↗
PubMed1978

[Comparative findings on the stability of plasmid resistance to antibiotics in vitro and in vivo].

The authors carried out comparative study of the incidence of spontaneous plasmide-negative variants occurrence in the S. aureus 8325phi IIde population developing under various conditions in vitro and in vivo. The mean percentage of such variants in the population developing in vitro constituted 0.9 +/- 0.2 in broth, 1.2 +/- 0.3 in the exudate, 6.3 +/- 2.0 in the population developing in vivo in the subcutaneous purulent-inflammatory focus, 9.5 +/- 2.6 in the kidneys. The mean percentage of plasma-negative variants in the purulent exudate in vivo was significantly greater than in the purulent exudate in vitro. The incidence of negative variants occurrence in vivo depended on the macroorganism properties.

Animals↗
PubMed1978

[Stability of drug resistance in staphylococci under various conditions and the effect on it of prolonged culture storage on artificial nutrient media].

The literature and experimental data on stability of resistance ot benzylpenicillin, streptomycin, tetracycline, chloramphenicol, erythromycin, kanamycin and methicillin in staphylococci stored for prolonged periods of time on artificial nutrient media were systematized. When the staphylococcal cultures were not in contact iwth the antibiotics for 5 to 18 months, sensitive cells to separate drugs were detected in 51.0--67.4 per cent of the strains. The number of such cells in the populations of some strains ranged from 1 to 100.0 per cent. The effect of the resistance multiplicity on the stability of resistance to benzylpenicillin, tetracycline, chloramphenicol and erythromycin was not observed.

Anti-Bacterial Agents↗
PubMed1976

[Mechanism of the heterogeneity of a staphylococcal population with respect to methicillin resistance].

The study of the staphylococcal population heterogeneity with respect to methicillin resistance by 2 methods revealed different numbers of the resistant cells in the population. Thus, when the microbial suspension was plated on an agarized medium with methicillin (50 gamma/ml), only 0.0007--0.0005 per cent of the resistant cells were found. When the colonies were replicated from a medium without methicillin to a medium containing methicillin (50 gamma/ml), 84.3--97.3 per cent of the resistant microbial cells were found in the population of the same strains. The main mechanism in the heterogeneity of the staphylococcal population with respect to methicillin resistance was impairement of the phenotype manifestation of the antibiotic resistance under definite conditions.

Culture Media↗
PubMed1976

[Method of determining the sensitivity of Staphylococcus aureus to methicillin].

The effect of the incubation temperature, i.e. 37 and 30 degrees and the effect of addition of 5 per cent of sodium chloride to the nutrient medium was studied with respect to the results of sensitivity determination of staphylococci to methicillin by 3 methods, such as serial dilutions in liquid and solid media and replica method applied to separate colonies. With the use of all 3 methods incubation of the samples at a temperature of 30 degrees increased the rate of staphylococcal cultures resistant to methicillin. Addition of sodium chloride to the solid nutrient medium increased the level of detecting methicillin resistant cultures in the samples incubated at a temperature of 37 degrees and decreased it in the samples incubated at 30 degrees.

Culture Media↗
PubMed1975

[Dynamics of the antibiotic sensitivity of the staphylococci in suppurative, inflammatory foci in patients during the period of the hospital stay].

The dynamics of staphylococci sensitivity to antibiotics in purulent foci of 242 in patients was studied. Two criteria were used for estimation of the above process, i.e. (I) sensitivity to the antibiotics of the whole staphylococcal population isolated and (2) sensitivity to the antibiotics of separate strains isolated from the population. In 10 or more days the number of the in-patients with staphylococci resistant to streptomycin, monomycin or oxacillin in the purulent foci increased. The number of the in-patients with penicillin, neomycin or chloramphenicol resistant staphylocci was statistically doubtful. The average number of the antibiotic resistant microbial cells in the staphylococcal populations of the foci in the patients during their stay in the hospital increased 2-4 times.

Anti-Bacterial Agents↗
PubMed1975

[Transmissivity of drug resistance in Salmonella].

The experiments showed that among 110 Salmonella strains resistant to 1 or more antibiotics 54.5 per cent of the cultures transfered their resistance to E. coli when grown in vitro. The frequency of the transmissive drug resistance in Salmonella was directly proportional to the number of r-determinants in R-factor. The cultures resistant to ampicillin and kanamycin proved to be the most competent donors.

Ampicillin↗
PubMed1975

[Transmissivity of the various R factors found among E. coli cultures circulating under natural conditions].

Transmissivity of drug resistance in wild strains of E. coli was shown to be determined not only by the presence of the transmissive factor and r-determinants in the microbial cell, but also by the functional activity of the R-factor. The capacity of the R-factor for transmission depended to a certain extent on the number of the r-determinants in the R-factor and the presence of various r-determinants in the R-factor.

Ampicillin↗
PubMed1975

[Epidemiological mechanism for the formation of drug-resistant bacterial populations].

The concept on the epidemiological mechanism of formation of drug-resistant bacterial populations was substantiated. Investigations showed the epidemiological mechanism of formation of the drug-resistant populations of staphylococci in the purulent-inflammatory foci to be represented in 81.4 per cent of the patients by superinfection with resistant microbes. The latter group of the patients could be divided into two subgroups: in one of the subgroups (34.9 per cent) a reduction of sensitivity in the initial staphylococci was seen in the presence of donor bacteria which later either remained in the focus or were eliminated. In this case it could be supposed that there occurred a preliminary infection with the resistant staphylococci or with the transducing bacteriophages.

Anti-Bacterial Agents↗
PubMed1975

[Methods for detecting drug-resistant staphylococci in the human body under natural conditions].

Two methods were compared for determination of drug resistant staphylococci on the nasal mucosa of patients, i. e. the routine method for determination of staphylococcal sensitivity to antibiotics and the method of direct plating out of the starting material onto agarized media containing antibiotics. Staphylococci resistant to streptomycin, tetracycline, chloramphenicol, erythromycin, monomycin, axacillin and less frequent to penicillin were found more often with the 2nd method. A method of proportions was developed for testing sensitivity of staphylococci in purulent inflammatory foci of the patients. It provided characterization of the staphylococcal population from the foci by the number of the antibiotic resistant microbial cells.

Anti-Bacterial Agents↗
PubMed1975

[Effect of penicillin on the intensity of formation of penicillin-resistant staphylococcal populations in the suppurative foci of patients].

The dynamics of sensitivity to penicillin of staphylococcal populations in purulent inflammatory foci of patients treated and not treated with antibiotics was estimated according to 4 indices. No reliable differences in the dynamics of sensitivity to penicillin were found in 2 groups of the patients, when estimation was performed with respect to the frequency of the penicillin resistant or penicillin sensitive staphylococci and detection of the penicillin resistant staphylococci by direct inoculation of the focal excretion to the medium with penicillin. A reliable increase in the percentage of the penicillin resistant staphylococci in the microbial population was observed only in the patients treated with penicillin.

Humans↗