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Biomedical subjects

A A Lentsner

Publications and source records attributed to A A Lentsner.

At least 19 recordsLinked to original sources
PubMed1992

[Biological characteristics of strains of lactobacilli, promising for use as eubiotics].

In the course of in vitro studies 3 Lactobacillus strains with pronounced antagonistic activity against some pathogenic and opportunistic bacteria (shigellae, enteropathogenic Escherichia, Proteus, staphylococci) were selected. In experiments on germ-free rats faint colonization by L. plantarum 37 was observed in the small intestine, as well as in the large intestine when low doses of these bacilli were introduced into the gastrointestinal tract of the animals. In vitro experiments demonstrated the decreased growth rate of this strain. The prophylactic administration of two eubiotic strains, L. plantarum 37 and L. fermentum 39, simultaneously with chloramphenicol to primates inhibited the growth of opportunistic bacteria, though L. fermentum 39 excessively suppressed the content of Escherichia coli in the enterobacterial population. The optimum biological effect was achieved with the therapeutic use of these three strains for the correction of dysbiotic disturbances caused by the administration of tetracycline in volunteers.

Adult↗
PubMed1991

[The adhesive properties of bacteria of intestinal origin].

Differences between strains of nonpathogenic Escherichia and lactobacilli, as well as some pathogenic bacteria of enteric origin (Escherichia, Shigella, Campylobacter), in their capacity to adhesion to rat enteric and colonic cells have been shown in vitro. The strains under study have been found to possess more pronounced adhesiveness with respect to colonic cells, which is indicative of their higher receptive capacity in comparison with enteric cells. In the absence of normal microflora lactobacilli and Escherichia exhibit increased adhesiveness with respect to enteric cells. Escherichia enterotoxigenic strains, Yersinia enterocolitica and Salmonella typhimurium virulent strains, Campylobacter jejuni clinical isolates possess more pronounced capacity for adhesion to enteric cells of Peyer's plaques than to other types of epithelial cells, which may be of importance in the pathogenesis of these infections.

Animals↗
PubMed1990

[Determination of the quantitative composition of fecal microflora].

Shifts in the quantitative composition of fecal microflora may be assessed by estimating the summary share (in per cent) of the bacterial groups associated with fecal microbiocenosis, this share being estimated by the nonparametric statistics methods. The ratio between potentially dominating and concomitant groups of microorganisms in fecal microbiocenosis helps estimate the severity of disorders in the quantitative composition of fecal microflora.

Diarrhea↗
PubMed1989

[Reciprocal effect of Klebsiella pneumoniae and Lactobacillus on their cytadhesion].

Reciprocal effect of 4 strains of Klebsiella pneumoniae and 6 Lactobacillus strains on their cytadhesion in mixed populations was studied on a model of formalinized human erythrocytes. The Lactobacillus strains included 2 strains of Lactobacillus casei subsp. casei, 2 strains of L. plantarum and 2 strains of L. fermentum. It was shown that adhesion of both the Klebsiella and the Lactobacillus strains changed under their reciprocal effect. The changes were characterized by the strain differences and depended on the quantitative ratio of the microorganisms.

Bacterial Adhesion↗
PubMed1989

[Species composition of intestinal lactoflora of healthy rhesus monkeys].

The results of the study of the species composition of the fecal microflora of 15 healthy rhesus macaques, from whom 204 strains of lactobacilli have been isolated and identified, are presented. The intestinal microflora has been shown to include different species, subspecies and biovars of homo- and heterofermentative lactobacilli and to possess definite individual properties. L. acidophilus, mannose-negative biovar I, and L. fermentum, mannose-negative biovars I and II, occur most frequently in feces. Certain differences in the species composition of lactoflora in monkeys and humans have been revealed: in the former, L. fermentum, mannitose-positive biovar III, and L. casei occur considerably more seldom. The inclusion of L. acidophilus strain I L. fermentum strains I and II isolated from rhesus macaques into eubiotics for these monkeys has been suggested.

Animals↗
PubMed1987

[Hemagglutinating and adhesive capacities of Klebsiella and Enterobacter strains].

The authors analyze the data of studies on the hemagglutinating and adhesive capacity of 290 cultures, including 118 K. pneumoniae strains and 64 E. cloacae strains isolated from sick children, as well as 59 K. pneumoniae strains and 49 E. cloacae strains isolated from healthy children. The hemagglutinating properties of the strains were determined in the hemagglutination test with fresh, formalin- and tannin-treated red blood cells, the adhesive properties were studied by light microscopy. Among K. pneumoniae and E. cloacae strains isolated in acute intestinal infections, mannose-sensitive hemagglutination and pronounced adhesive activity were prevalent in most cases. Poorly adhesive and nonadhesive strains were characteristic of K. pneumoniae and E. cloacae cultures isolated from healthy children. The strains isolated from sick and healthy children differed only by the prevalence of adhesive cultures.

Acute Disease↗
PubMed1987

[Lactobacillus flora and colonization resistance].

Lactobacillus flora of healthy persons and the properties influencing the protective function of lactobacilli are described. It was shown that the species and quantitative composition of the Lactobacillus flora in healthy persons was characterized by individual features and the Lactobacillus flora of separate microbiotopes was different. Furthermore, the properties defining the protective function of lactobacilli in the host: colonization capacity, direct antimicrobial activity and interference with other protective mechanisms were also different in separate species and even strains.

Adult↗
PubMed1986

[Effect of antibiotics on the adhesive properties of microorganisms and an available model for its study].

The effect of benzylpenicillin, ampicillin, bicillin-3, carbenicillin, levomycetin, erythromycin, streptomycin and kanamycin on the adhesive properties of 9 test microbes including 5 strains of Lactobacillus from human microflora, 3 uropathornic strains of E. coli and 1 strain of S. aureus was studied with the method developed by the authors. The method is based on the use of formalinized human erythrocytes as macroorganism cells. It was shown that the antibiotic inhibitory effect on adhesion depended on mechanism of action of the antibiotics and their concentration, was associated with the level of the microbial adhesion and did not depend on the microbial sensitivity to the drugs.

Adhesiveness↗
PubMed1986

[Enhancement of the phagocytic activity of cells of the mononuclear phagocytosing system by the peroral administration of lactobacilli].

The phagocytic function of the peritoneal exudate cells after oral and intraperitoneal administration of Lactobacillus casei subsp. casei, L. plantarum and L. fermentum was studied on mice C57Bl and inbred rats CDF/F344/Crl. The phagocytic function was estimated by the capacity for absorbing and excreting 14C-labeled typhoid vaccine. Intraperitoneal administration of a mixture of various Lactobacillus strains resulted in two-fold increase of the bacteria absorption and digestion when the Lactobacillus strains were administered 4 days before administration of the test antigen. On their simultaneous administration the phagocytic function of the peritoneal exudate cells lowered. Oral administration of the Lactobacillus strains for 6 and 18 days resulted, respectively, in 1.5- and 3-fold increase of absorption and digestion of the labeled typhoid vaccine. This route of Lactobacillus administration provided more rapid increase of the level of the antibodies to the typhoid antigen. Possible immunomodulating action of Lactobacillus administered orally is discussed.

Absorption↗
PubMed1982

[Intestinal mucosa of gnotobiotic rats administered lactobacilli].

When lactobacilli are administered to gnotobiotic rats (Fischer strain), a gradual increase of lymphocytic, eosinophilic and mast cell infiltration of the intestinal connective tissue stroma, dilatation of vessels and their filling with lymphocytes is observed. Radioautographically 7 months later, migration and differentiation of enterocytes in the crypta--villus system of the iliac mucous tunic increases. In the mesenteric lymph nodes the postcapillary venules increase in number, lymphocytes migrate out of them, focal plasmocytic reaction with presence of some blastic forms takes place. Specific antibodies for lactobacilli in the blood serum either are absent or occur in low titers (1:2-1:8). Owing to the data obtained, a conclusion can be made on a weak immunogenecity of the lactobacilli. Their administration to the germ-free rats produces a certain cellular reaction, probably T-dependent, though any definite signs of hormonal response are absent. One--14 days after lactobacilli have been injected, in the rat intestine mucous tunic no microorganisms are revealed to fix to enterocytes. In cytoplasm of the absorbtive cell villi, the Golgi complex is subjected to hyperplasia and occupies an essential area over the nucleus. Within its cysterns, as well as in the mitochondrial and nuclear membrane areas, myelin-like bodies are revealed; evidently, they demonstrate certain changes in peroxidic oxidation of lipids..

Animals↗
PubMed1982

[Adhesive and hemagglutinating properties of lactobacilli].

The study of the adhesive and hemagglutinating properties of the strains of different Lactobacillus species isolated from the human digestive tract and sour milk products were carried out. 49 strains of 9 Lactobacillus species were studied; of these, 10 strains had been isolated from saliva, 11 strains from feces, 7 strains from milk and 5 strains from sour cream. 11 collection strains and 2 strains used in the production of lactobacterin served as controls. Adhesion was studied in vitro on human red blood cells used as a model. Red blood cells used in the experiments had been taken from 23 donors aged 25-52 years. Lactobacilli were found to have certain inter and intraspecific differences in their adhesiveness. The adhesiveness of the lactobacilli isolated from human feces was considerably greater than that of the strains isolated from sour milk products and of the collection strains. Only the strains of lactobacilli with low adhesiveness possessed pronounced hemagglutinating properties.

Adhesiveness↗
PubMed1975

[Ability of lactobacilli in the human microflora to produce lysozyme].

Lysozyme activity of 403 strains of lactobacilli were investigated; of these 26 were from foreign sets and 377 were isolated from the contents of the stomach, feces and vaginal discharge of healthy adults. The species reference of lactobacillae was confirmed by the results of study of their physiologo-biochemical properties with the aid of 45 tests. A method of agar plates was adapted to determination of lysozyme: the autoclaved suspension of Micrococcus lysodeikticus (strain No. 2665) was added to the agar medium MPC-I, and lactobacilli were cultivated for 4 days in the CO2 atmosphere at 37 degrees C. There was revealed the capacity of L. fermenti and L. brevis to produce lysozyme; in L. fermenti the lysozyme activity was much more frequent (p less than 0.001); strains of the rest of the species of lactobacilli differentiated by the Rogosa and Sharpe's classification proved to be lysozyme-negative. It was shown that the lactobacilli of the L. fermenti species, included into the microflora of the intestine and the vagina of healthy adults as a rule possessed lysozyme activity. L. fermenti strain 90T-S4 used in the production of dry lactobacterin also produced lysozyme. All this favours an important role of L. fermenti in the protective function of the microflora.

Adult↗