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Biomedical subjects

B A Shenderov

Publications and source records attributed to B A Shenderov.

At least 19 recordsLinked to original sources
PubMed1992

[The pathogenicity factors of bacteria in the genus Acinetobacter].

Eighty Acinetobacter strains, isolated in Togliatti from patients with purulent inflammatory diseases, were studied to determine their pathogenicity factors. Out of these 80 strains, 32.5% were found to have enterotoxigenic activity and 46.2%, adhesive activity. They were related to adhesins of the human type and to adhesins of the sheep, rabbit, swine and guinea pig types. But the most important phenomenon established in this study was the combination of different pathogenicity factors detected in Acinetobacter bacteria. Analysis of the combination of pathogenicity factors revealed that 7.5% of Acinetobacter strains had adhesive and enterotoxigenic activity, 15.3% of these strains combined adhesive and hemolytic activity and 1.2% of them were found to be enterotoxigenic and hemolytic. Only 5.0% of Acinetobacter strains were found to carry all there pathogenicity factors simultaneously.

Acinetobacter↗
PubMed1992

[Microbial ecology of laboratory animals as a model in evaluation of the immunomodulating and antimicrobial agents].

Rats with altered microbial ecology and decreased colonization resistance due to neutropenia induced by cyclophosphamide were used as a model for estimating the effect of bacterial polysaccharides (lactulose and exopolysaccharide from Bacillus polymyxa) and fluoroquinolones (pefloxacin). Monotherapy with pefloxacin had a favourable effect both on normalization on the intestinal microflora in the rats and their hemopoiesis (decreased neutropenia). The highest correcting effect with respect to the lowered colonization resistance was observed when pefloxacin was used in combination with exopolysaccharide.

Adjuvants, Immunologic↗
PubMed1991

[The effect of chemical preparations on the biological properties of the intestinal lactobacilli in experimental animals].

The oral administration of the therapeutic doses of tetracycline, pefloxacin, ampicillin, cephalexin, rifampicin, sisomicin to Wistar rats for 5 days was accompanied by a decrease in the total number of lactobacilli in feces and by changes of the species spectre of these microorganisms. In those rats species, never found in intact animals, could be revealed rather frequently. All antimicrobial preparations administered in this investigation induced a decrease in the proportion of antibiotic-sensitive cultures and led to the selection of strains having multiresistance and increased antagonistic activity with respect to Pseudomonas indicator strain. The possible relationship between the markers antibiotic resistance and antagonistic activity in lactobacilli is discussed.

Administration, Oral↗
PubMed1991

[Effect of antibiotics on fecal excretion of various products of microbial metabolism of aromatic amino acids].

The model experiments on intact albino rats and those exposed to lincomycin, ampicillin and rifampicin showed that intragastric administration of the three antibiotics to the laboratory animals in therapeutic doses for 8 days induced statistically significant changes in the fecal excretion of n-cresol, indole and skatole, microbial metabolites of aromatic amino acids in the gastrointestinal tract of a macroorganism. The results are in favour of using biochemical tests for rapid diagnosis of the intestinal microflora response to antimicrobial agents.

Amino Acids↗
PubMed1990

[Penicillin-binding proteins of various strains of Lactobacillus].

Sensitivity of different species of Lactobacillus i.e. L. casei, L. plantarum, L. acidophillus, L. buchneri, L. jugurti and others to penicillins and cephalosporins of various generations was studied. Penicillin binding proteins (PBPs) of the Lactobacillus species were specified. It was shown that the number of PBPs depended on the Lactobacillus species. L. casei had the least number of PBPs (4) and L. brevis had the highest number of PBPs (11). Competition of 14C-benzylpenicillin with ampicillin, cefotaxime, ceftizoxime and cefoperazone for binding to separate PBPs in three strains of different Lactobacillus species was investigated.

Ampicillin↗
PubMed1990

[Transfer of various markers in Lactobacilli during transformation of plasmid DNA and joint cultivation].

A system providing a high frequency genetic transfer of various markers making the reference strain Lactobacillus buchneri 1837 resistant to Lm, Em and Fus, able to ferment some carbohydrates and antagonistic against Pseudomonas diminuta CCM 2657 was developed. The frequency of the marker transfer during the lactobacilli joint cultivation was 1.5 X 10(-5) = 5.5 X 10(-5) to 1.5 X 10(-4) = 5.5 X 10(-4) which was 3-4 orders of magnitude higher than the marker transfer frequency during transformation of L. buchneri NRRLB 1837 with plasmid DNA of different lactobacilli. The recombinants and transformants resulting from the joint cultivation of lactobacilli contained a plasmid about 60 kb in length which provided cells of L. buchneri NRRLB 1837 with resistance to fusidin, antagonistic activity against Pseudomonas diminuta and capacity for utilizing sucrose and sorbite. It was shown possible to integrate the plasmid DNA about 26.5 kb in length contained in the cells of L. casei MT 205 to the chromosomes of erythromycin resistant transformants. The results of the investigation of the biological properties of the recombinants and transformants and their plasmid profiles were confirmed with the Southern DNA-DNA hybridization.

Anti-Bacterial Agents↗
PubMed1990

[Isolation of plasmid DNA from Bifidobacterium].

Conditions for accumulation of the biomass and a procedure for isolation of plasmid DNA from bifidobacteria in microquantities were developed. It was shown that all the strains tested had 1 to 3 plasmids of different molecular weights electrophoretically detected. Relation between the detected plasmid DNA and bifidobacteria resistance to tetracycline and fusidin as well as utilization of some carbohydrates is discussed.

Bifidobacterium↗
PubMed1989

[Effect of cephalexin on the colonization resistance of the large intestine in experimental animals].

It was shown morphologically and microbiologically that cephalexin administered intragastrically in a dose of 2 g/kg induced deep microecological changes in the cecum of Wistar albino rats. Scanning electron microscopy revealed that a single use of cephalexin in the above dose resulted in almost complete elimination of the biofilm from the surface of the cecum mucosa and it inflammation. This was accompanied by an increase in the number of potentially pathogenic bacteria and broadening of the spectrum of the phage variants of coliform bacilli present in the animal feces, as well as by change the periods of coliform bacilli persisting in the large intestine.

Animals↗
PubMed1989

[Effect of sisomicin on intestinal microflora and colonization resistance in rats and their offspring].

In experiments with Wistar female rats it was shown that after administration in the form of inhalations (10.87 mg/m3) sisomicin was present in the animal feces in a concentration of 26.6 micrograms/g. Prolonged exposure to the antibiotic during the pregnancy term led to changes in microbiocenosis of the animal large intestine which was observed even a month after the delivery. The progeny of the animals was characterized by the presence of significant numbers of aerobic bacteria resistant to sisomicin and potentially pathogenic gram-negative bacteria including various species of Proteus in the intestine, as well as by higher periods of persistence of Klebsiella indicator strains administered orally.

Animals↗
PubMed1989

[Effect of antibiotics on excretion of various microbial metabolites with feces].

Concentrations of volatile fatty acids, free amino acids, ammonia, protein, carbohydrates, carboxylic acids and some cations were determined in feces of intact animals (rats) chromatographically and spectroscopically. Oral administration of 8 chemotherapeutic drugs in the therapeutic doses to the animals resulted in changing excretion of the majority of the above compounds associated with vital activity of the large intestine microflora which depended on the drug type. Investigation of metabolic activity of normal microflora of the gastrointestinal tract is shown promising for estimation of intestinal microbial biocenosis.

Amino Acids↗
PubMed1989

[Mechanism of antagonistic activity of lactobacilli].

Different species of lactobacilli, when grown together with salmonellae and shigellae, have been found to inhibit their growth and proliferation. The supernatants of the culture fluids of 8 species of lactobacilli have been shown to contain natural metabolites, other than lactic acid, with a wide spectrum of antibacterial activity with regard to different opportunistic aerobic and anaerobic microorganisms. The relationship between the antagonistic activity and the presence of plasmid DNA in a number of the most active antagonistic lactobacilli is discussed.

Antibiosis↗
PubMed1989

[Microbiological and biochemical indices of changes in microbial ecology of rat large intestine under the effect of rifampicin].

Intragastric administration of rifampicin to rats in a dose of 40 mg/kg resulted in decreasing of the contents of grampositive cocci and lactobacilli and increasing of the number of gramnegative aerobic potentially pathogenic bacteria in feces of the experimental animals. It was noted that along with changes in the composition of the fecal microflora after the exposure to the antibiotic there were disorders in feces excretion of ammonia and amino acids such as alanine and glutamic acid as well as lactic, amber, butyric, valeric and alpha-ketoglutaric acids. Reduction of the changed biochemical indices was shown to be slower than that of the routine microbiological indices.

Animals↗
PubMed1989

[Changes in the microbial ecology and morphology of large intestine biofilm in albino rats under the influence of rifampicin].

After oral administration in single doses of 40 and 160 mg/kg to Wistar rats rifampicin was detected in 3 hours in the contents of the large intestine The maximum rifampicin concentrations in the feces (120 and 300 micrograms/g) were detected in 24 hours. The antibiotic was present in the animal feces for 6-7 days. The antibiotic administration led to marked changes in microbiocenosis of the large intestine: disappearance of coccal flora, lower quantities of Escherichia and Lactobacillus and lower total quantities of anaerobic bacteria. It was also accompanied by changes in the structure of the typhlon biofilm. By the 28th day after discontinuation of the antibiotic administration (the end of the observation period) the large intestine microflora did not recover completely.

Animals↗