[Study of sensitivity of microflora isolated from biosubstrates of surgical profile patients to bacteriophage].

AIM: Study sensitivity of nosocomial microbes--causative agents of post-operative infectious complications in surgical profile patients to bacteriophages. MATERIALS AND METHODS: Microbe isolates from biosubstrates of 223 surgical patients served as material. Microbes were isolated from blood, urine, wounds, intravascular catheters, abdominal cavity drainage, discharge of pharynx, trachea (343 strains). Phagolysability of strains was determined by Ott method. RESULTS: A good lysability of Pseudomonas aeruginosa, Klebsiella, Escherichia coli by specific complex and monophages and lower--of staphylococci and enterococci was found in the presence of 83% methicillin-resistant staphylococci strains and 94% Gram-negative bacteria strains producing extended spectrum beta-lactamases. CONCLUSION: Continuation of use of various bacteriophage preparations against Gram-negative bacteria and implementation of measures to adopt phage preparations to staphylococci and enterococci are perspective considering multiple resistance of microbes to antibiotics.

[Genotypic features of Pseudomonas aeruginosa strains circulating in surgical hospital].

AIM: To study genetic diversity of Pseudomonas aeruginosa strains circulating in intensive care unit (ICU), to determine the source of these strains and duration of circulation of epidemically-significant clone in the hospital. MATERIALS AND METHODS: Genotyping of 106 P. aeruginosa strains isolated from patients, clinical specimens and fomites was performed by random amplified polymorphic DNA analysis with oligonucleotide primer Sh1 of 10 bp long. RESULTS: Out of 106 P. aeruginosa isolates, 72.6% belonged to the same genotype, which was dominated in ICU during whole study period. It was established that 58.3% of examined patients were colonized by identical strains belonged to prevalent genotype that indicates the intrahospital transmission of epidemic strain. CONCLUSION: Obtained data show that during the period of observation (15 months) one clone of P. aeruginosa dominated in ICU, which was characterized by multiple resistance to antibiotics and caused nosocomial infection in 58.3% of patients. This confirms the need of continuous molecular-microbiological monitoring of hospital microflora in order to early detect potentially dangerous epidemic hospital strains, which are able to cause nosocomial infections.

[Enterococci as a cause of infectious complications after surgery].

Self-obtained data about study of enterococci as etiologic agents of infectious complications after cardiovascular and transplantation surgery are presented in the article. 465 strains of enterococci were isolated from different biosubstrates. Isolation rate of different species of enterococci in blood, urine, fromwounds, trachea, cardiacvalves, as well as in the environment and on wear of healthcare workers were determined. Most frequently enterococci were isolated from urine (47.7% of cases) and from trachea (24.3% of cases). Enterococcal bacteremia was determined in 9.7% of cases and represented a significant part in Grampositive microflora--38.5% of all isolates. High resistance of enterococci to antibiotics and well lysis by phages were noted.

[Effect of concanavalin A on the splenic lymphocyte proliferative activity of germ-free rats]. / Vliianie konkanavalina A na proliferativnuiu aktivnost' limfotsitov selezenki bezmikrobnykh krys.

Action of Con-A on the proliferative activity of spleen lymphocytes was studied using germfree and conventional Fisher rats 3-4 months of age and conventional 2-3 day old rats. The intensity of 3H-thymidine incorporation in lymphocytes of germfree and conventional animals was the same, however, the coefficient of stimulation was higher in germfree rats. Lymphocytes of suckling rats had a low reactivity to Con-A.

[Morphological and immunomorphological changes in the intestines and regional lymph nodes of gnotobiotic rats--chronic carriers of Vibrio cholerae El-Tor]. / Morfologicheskie i immunomorfologicheskie izmeneniia v kishechnike i regionarnykh limfaticheskikh uzlakh pri khronicheskom nositel'stve kholernogo Vibriona El'-Tor u krys gnotobiontov.

In the course of chronic carrier state of El-Tor vibrio cholerae gnotobiotic rats develop an immunomorphological reaction in the mucous membranes of the small and large intestines, Peter's patches, and mesenterial lymph nodes consisting in activation of reactive centers of follicles, hyperplasia of reticular cells, and an increase in the number of pyroninophilic plasma cells. The vibrio cholerae caused no pathological changes in enterocytes and other cells but its inoculation was accompanied by a "minor inflammation" in the intestinal wall and mesenterial lymph nodes. Eosinophilic infiltration in the intestinal tract, intensive mast cell reaction with degranulation in the small and large intestines and regional lymph nodes was observed.

[The autologous intestinal microflora in the postresuscitation period after acute blood loss in rats]. / Automikroflora kishechnika v postreanimatsionnom periode posle ostroi krovopoteri u krys.

In this work the data obtained in the study of intestinal microbiocenosis in rats on the third day of the postresuscitation period after acute blood loss are presented. The quantitative and qualitative shifts of microflora at different biotopes, such as the wall of the small intestine, the parietal microflora of Peyer's patches, the contents and wall of the large intestine, have been characterized. Some specific features of dysbiotic changes have been revealed in comparison with the shifts of intestinal microflora in cases of dysbacteriosis caused by other reasons. The translocation of different microorganisms, including Bacterium bifidum and lactobacilli, into mesenteric lymph nodes, the liver, the spleen and the blood has been observed.

[The functional activity of the macrophages in experimental intestinal dysbacteriosis in rats]. / Funktsional'naia aktivnost' makrofagov pri éksperimental'nykh disbakteriozakh kishechnika krys.

The study of the functional activity of macrophages in the peritoneal exudate and spleen of Sprague-Dawley rats was made under the conditions of dysbacteriosis caused by the administration of antibiotics (gentamicin and phenoxymethylpenicillin) and short-term food deprivation. The complex study of the key functions of macrophages, carried out on the same pool of cells, showed that under the conditions of antibiotic therapy the enhanced function of ingestion was accompanied by a decrease in all other investigated functional parameters of peritoneal macrophages: the intensity of protein synthesis, oxidation metabolism, the activity of lysosomal apparatus, 5'-nucleotide activity. In contrast to changes observed in macrophages after the administration of antibiotics, short-term food deprivation induced increased functional activity as shown by most tests used in this investigation (such as tests for the ingestion of sheep red blood cells, 51Cr, nitro blue tetrazolium, acridine orange, 5'-nucleotidase activity), but did not affect the intensity of protein synthesis in macrophages. The comparison of these results with the data obtained by the authors after the administration of an immunomodulating agent made it possible to regard short-term food deprivation, judging by its effect on the functional activity on macrophages, as an immunostimulating action.

[The characteristics of the colonization resistance of the intestines in conventional animals with a history of clinical death]. / Kharakteristika kolonizatsionnoi rezistentnosti kishechnika konventsional'nykh zhivotnykh, perenesshikh klinicheskuiu smert'.

After modeling the terminal state caused by the acute loss of blood in rats their intestinal microflora was studied, as was their resistance to colonization. Decreased resistance to colonization was registered early after resuscitation (up to 3 days), which was confirmed by the translocation of bacteria into internal organs, decreased number of lactobacilli in the contents of the small intestine and elevated level of enterobacteria in the intestine. Disturbances in resistance to colonization was also manifested by prolonged colonization of the digestive tract of the resuscitated animals by Escherichia coli indicator strain K12pSS-120 carrying Shigella sonnei (phase I) invasiveness plasmid.

[The adhesive properties of a nonenteropathogenic strain of Escherichia coli in systems in vitro on isolated rat enterocytes and in vivo]. / Adgezivnye svoistva neénteropatogennogo shtamma Escherichia coli v sistemakh in vitro na izolirovannykh énterotsitakh krys i in vivo.

The adhesive properties and colonizing capacity of E. coli strain O83, isolated from feces of healthy humans and marked according to its resistance to rifampicin and nalidixic acid, were studied. In vivo experiments on germ-free rats revealed that these bacteria were capable of colonizing intestinal mucosa; colonization increased from the small to large intestine and E. coli cells were mainly concentrated in the intestinal lumen and in mucin. In vitro studies showed that this nonenteropathogenic E. coli strain possessed pronounced adhesive properties with respect to the colonic cells of germ-free rats; these properties were considerably less pronounced with respect to the enteric cells of the small intestine. The electron microscopic study of E. coli cells revealed the presence of fimbriae and fibrillae on their surface.

[The adhesion of clinical isolates of Campylobacter jejuni to intestinal epithelial cells in vitro]. / Adgeziia klinicheskikh izoliatov Campylobacter jejuni k épitelial'nym kletkam kishechnika in vitro.

The adhesive activity of C. jejuni isolated from feces of children with Campylobacter infection was studied with the use of a newly developed model. 47 clinical isolates were analyzed; of these, 91% were found to be enteroadhesive to a variable degree. As the result of in vitro studies, Campylobacter were found to have much greater tropism to colonic cells and epithelial cells of Peyer's patches in comparison with the epithelial cells of the small intestine. The correlation between the degree of adhesive activity and the severity of the course of Campylobacter infection in children.

[Delayed hypersensitivity in the chronic cholera vibrio carrier state in animals with an absence of normal microflora]. / Giperchuvstvitel'nost' zamedlennogo tipa pri khronicheskom kholernom vibriononositel'stve u zhivotnykh s otsutstviem normal'noi mikroflory.

The development of allergy in germ-free rats in chronic vibriocarriership was studied. The formation of specific delayed type hypersensitivity was found to occur to a limited extent in the animals devoid of normal microflora. The picture of hyperergic inflammation was revealed in the lymph nodes of vibriocarrier rats, the test for specific allergen being positive.

[The binding of lactobacilli with soluble proteins and lectins]. / Sviazyvanie laktobatsill s nekotorymi rastvorimymi belkami i lektinami.

The capacity of lactobacilli for binding with mucin (M), fibronectin (FN) and Concanavalin A (Con A) has been studied. Most of 33 strains of 8 Lactobacillus species have been found to possess a sufficiently high level of adhesion to immobilized FN and Con A and a low level of adhesion to M. The presence of inverse correlation between the binding of lactobacilli with M and FN has been established. This study has shown that the capacity of lactobacilli for adhesion to some soluble proteins and lectins is an additional marker for their characterization and can be used for the targeted correction on the intestinal microflora.

[Sensitivity of nosocomial microflora circulating in a transplantation clinic to medicinal bacteriophages]. / Chuvstvitel'nost' nozokomial'noi mikroflory, tsirkuliruiushchei v transplantatsionnoi klinike, k lechebnyum bakteriofagam.

The sensitivity of 239 isolates obtained from patients with postoperative infectious complications to phagolysis was determined. Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli were found to have the highest sensitivity to phages. Variations in the sensitivity of the same cultures to phages from different producers and even from the same producer were established. The sensitivity of cultures to phages may serve as an additional criterion of the biological properties of strains and their marker.

[Local shwartzman phenomenon in animals with a complete absence and a reduction of the normal microflora]. / Mestnyi fenomen Shvartsmana u zhivotnykh pri polnom otsutstvii i reaktsii normal'noi mikroflory

Macro- and microscopic changes were studied in case of reproduction of the local Schwartzmann phenomenon in animals with various extent of bioisolation. It was revealed that the Schwartzmann phenomenon was positive in the usual animals and negative in the germ-free guinea pigs and in the animals with reduced enteric microbial flora given sterile diet. In the absence of microscopic changes in the germ-free animals there was revealed in their skin a neutrophilic-mononuclear infiltration of the derma, dilatation of the vessels, thrombosis of individual vessels. Apart from the same changes in guinea pigs with a reduced microbial flora, there were found focal extravasation and thrombosis of a somewhat greater number of vessels. There was no marked thromboses of small branches of the vessels, extensive hemorrhages or necroses which usually accompanied positive Schwartzmann phenomenon.

[Biological characteristics of strains of lactobacilli, promising for use as eubiotics]. / Biologicheskia kharakteristika shtammov laktobatsill, perspektivnykh v kachestve éubiotikov.

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.

[The prevention of the translocation of intestinal microflora after the rescue of an organism from a terminal state]. / Profilaktika translokatsii kishechnoi mikroflory posle vyvedeniia organizma iz terminal'nogo sostoianiia.

In experiments on guinea pigs, the animals were resuscitated from clinical death caused by the acute loss of blood and subsequently treated intragastrically with enterosorbents: activated carbon fibrous material, alone and in combination with polymyxin B, polyphepan (a lignin derivative), polymethyloxan hydrogel and the sorbent Enterocat. In the animals, not treated during the postresuscitation period, a high population level of enterobacteria and Gram-positive aerobic cocci was registered in the contents of the small and large intestines and their translocation to mesenteric lymph nodes, liver, spleen and blood was observed. The amount of lactobacilli in the small intestine was decreased. Enterosorbents were found to decrease a high population level of intestinal microflora, to prevent the translocation of Gram-positive aerobic cocci and to inhibit the penetration of enterobacteria through the enteric barrier in the postresuscitation period. Combined use of activated carbon fibrous material with polymyxin B proved to be most effective for the elimination of enterobacteria.

[The adhesive properties of bacteria of intestinal origin]. / Adgezivnye svoistva bakterii kishechnogo proiskhozhdeniia.

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.

[The Amben regulation of the intestinal microflora and macrophage functional activity in an experiment]. / Reguliatsiia ambenom kishechnoi mikroflory i funktsional'noi aktivnosti makrofagov v éksperimente.

The possibility of the correction of intestinal microflora disorders and the functional activity of macrophages in dysbiosis, caused by the intragastric administration of ampiox, with the use of amben (PAMBA), an inhibitor of proteolytic enzymes, was studied. Quantitative and qualitative changes in the main representatives of automicroflora, the functional activity of macrophages in the phagocytosis of 51Cr-labeled sheep red blood cells, the intensity of protein synthesis, the content of cathepsin D, acidic phosphatase and nitro blue tetrazolium activity were determined. The combined administration of ampiox and amben normalized quantitative and qualitative ratios of the main representatives of intestinal microflora, as well as the characteristics of macrophage functional activity, studied in this investigation. The administration of amben to intact animals was found to stimulate bifido- and lactoflora.

[The proteolytic activity of the contents of the normal large intestine and in microecological disorders]. / Proteoliticheskaia aktivnost' soderzhimogo tolstoi kishki v norme i pri mikroékologicheskikh narusheniiakh.

The proteolytic (caseinolytic) activity of fecal supernatants obtained from 52 practically healthy children and 220 children with the etiologically undetermined (unclear) diagnosis of gastrointestinal tract dysfunction has been studied. As revealed in this study, in cases of bacteriologically confirmed microecological disturbances in the intestine, accompanied by the activation of opportunistic microflora, the caseinolytic activity of fecal supernatants increases. The determination of the level of the caseinolytic activity of fecal supernatants on solid culture media as a rapid method, specially intended for the diagnosis of dysbiotic states of the gastrointestinal tract, is proposed.

[Gnotobiotic studies to determine the colonization resistance of the intestines]. / Gnotobiologicheskie issledovaniia v opredelenii kolonizatsionnoi rezistentnosti kishechnika.

The literature data and the results of the author studies on determination of intestine colonization resistance are presented. The mechanisms of the colonization resistance defined by the macroorganism factors and representatives of indigenic microflora are discussed. The results of the experiments with animal gnotobiotes aimed at elucidating new aspects of the colonization resistance mechanism: antagonistic interrelations between pathogenic and nonpathogenic bacteria and the role of transitory microflora, factors lowering the colonization resistance are presented. The up-to-date methods for testing the colonization resistance and the ways for its increasing are indicated.