[The pathogenetic aspects of the hyaluronidase activity of Proteus mirabilis]. / Patogeneticheskie aspekty gialuronidaznoi aktivnosti Proteus mirabilis.

The hyaluronidase activity of 83 P. mirabilis strains has been studied. The strains isolated from patients with chronic urologic infection possess the highest hyaluronidase activity, while the activity of strains isolated in cases of enteric disturbances and from purulent wound exudate has proved to be considerably lower, the difference between the latter being statistically insignificant. The hyaluronidase activity of P. mirabilis may be increased when the culture is grown in the presence of blood serum, and in strains isolated from internal organs an increase in hyaluronidase activity and the production of slime-like substance by bacterial cells can be observed. After the parenteral infection of animals with paired strains differing in their hyaluronidase activity differences in the course of infection were noted.

[The secreted proteolytic enzymes of Proteus mirabilis]. / Sekretiruemye proteoliticheskie fermenty Proteus mirabilis.

Experiments on white mice, made with the use of genetically linked pair of P. mirabilis differing in the presence of protease activity, have demonstrated the role of this activity in the aggravation of the infectious process, observed only in cases of the parenteral introduction of microorganisms. The damaging action of proteases manifests by decreased antiprotease capacity of the blood and the dissemination of bacteria into organs and tissues with the predominant colonization of the urinary tract. The damage of the epithelial barrier of the gastrointestinal mucosa after the intragastric administration of bacteria can be observed after preliminary destruction of the protective layer consisting of mucin and containing sIgA.

[The mechanisms of Proteus mirabilis resistance to the bactericidal action of blood serum]. / Mekhanizmy ustoichivosti Proteus mirabilis k bakteritsidnomu deistviiu syvorotki krovi.

When studying sensitivity of Proteus mirabilis to bactericide effect of blood serum the resistance to alternative way of the complement activation was found in a number of strains. The population of cells with morphologically determinable changes of the surface structures resistant to bactericide effect of the serum is formed as affected by the blood serum of the culture P. mirabilis. Proteus proteases capable to inactivate the complement components are one of the factors of P. mirabilis resistance to bactericide effect of the complement.

[The characteristics of the initial link in the intestinal lesion by opportunistic Proteus mirabilis bacteria]. / Osobennosti initsial'nogo zvena pri porazhenii kishok uslovno patogennymi bakteriiami Proteus mirabilis.

Interaction of Proteus mirabilis with the intestine epithelium in white mongrel mice has been studied by means of bacteriological, toxicological and electron microscopic methods. Introduction of the agar culture of bacteria to the intestine lumen has permitted finding its general toxic action on enterocytes and other cell elements of epithelium which was accompanied by a potentiation of the striated margin membrane degradation but caused no destruction of cells. A damaging factor of protei was connected with the thermostable large-molecular fraction of cultural fluid of bacteria and its action was traced at the first hours of the bacterial contact with the mucous surface of thin intestine. Preliminary weakening of protective barriers of the intestine mucosa permitted protei to penetrate deep into the tissue through the intercellular slots. Colonization of the intestine lumen wall zone by the proteus is a necessary condition of the above-mentioned changes.

[The characteristics of the contact of proteolytic strains of Proteus mirabilis and Klebsiella pneumoniae with enterocytes in vivo]. / Osobennosti kontakta proteoliticheskikh shtammov Proteus mirabilis i Klebsiella pneumoniae s énterotsitami in vivo.

The relationships of opportunistic P. mirabilis and K. pneumoniae, both having proteolytic properties, with enteric cells in white mice have been studied on a ligated intestinal loop, used as an experimental model, by electron microscopy. This investigation has shown that the strains under study are capable of damaging the membrane of the jagged edge of enteric cells at the distance of the spread of proteolytic metabolites. This damage is reversible, presenting as compensatory protective reaction of the cells.

[Serotyping of Proteus using a rapid system]. / Serotipirovanie proteev s pomoshch'iu rapid-sistemy.

A rapid method for Proteus serologic typing is suggested, based on Soviet commercial diagnostic adsorbed type sera. The rapid system involves replacing two-staged typing with one-staged, making use of polyvalent sera constructed by uniting 8-9 type sera according to the suggested schemes. O- and H-antigens are types in accordance with special tables. Fifteen O-antigens and 4 H-antigens, whose total incidence among Proteus clinical strains is under 2 percent, cannot be typed with the use of this system. The suggested rapid system is suggested as a rapid simple method for typing Proteus clinical strains in intricate epidemiologic situations.

[The phospholipases of Proteus mirabilis]. / Fosfolipazy Proteus mirabilis.

The method of screening Proteus for phospholipase activity has been worked out. The study of isolated clones of the same strain, used as an example, has revealed that clones differing in their phospholipase activity also differ in virulence and in some parameters of interaction in the host-parasite system. P. mirabilis phospholipases are supposed to be of importance as one of the factors contributing to the invasive properties of these microorganisms at the stage of overcoming the epithelial cell barrier of mucous membranes.

[A method for determining phospholipases in microorganisms]. / Metod opredeleniia fosfolipaz mikroorganizmov.

A method is suggested for the determination of bacteria phospholipases in dense nutrient medium. The medium contains the egg-yolk solution, buffer pH 9.2, meat extract, calcium chloride and toluidine blue. The enzyme activity is estimated by the diameter value of the medium clarification zone around the bacterial mass inoculation by injection into an agar plate. It is possible to study 6-8 strains on one Petri dish. This method is a simple one and thus it can be used in the bacteriological practice when determining phospholipases of bacteria, especially in strains of those species where this enzyme is a pathogenicity factor.

[Proteus adhesion to intestinal epithelium]. / Adgeziia proteev k kishechnomu épiteliiu.

The adhesive properties of Proteus strains isolated from different sources have been studied under conditions similar to the real interaction of microorganisms with the epithelial cells of intestine. A comparison of the adhesive properties of Proteus and of colon Bacillus has shown that the value of the strong adhesion to the mucosa of Proteus isolated under enterocolitis at the same bulk concentrations of the infectious suspension is 2-3 order less than that of E. coli. The adhesion of Proteus to the surface of epithelial cells begins at bulk concentrations exceeding those for the colon Bacillus by 3-4 orders. Besides, a toxic effect of number of freshly isolated Proteus strains on the epithelial cells of intestine mucosa is observed. Strains isolated from patients with diarrhea and from environment differed from each other in the studied criteria. A conclusion is drawn that at the initial stage of the interaction with the intestine mucosa the Proteus strains differ considerably from the indigenous strain of the colon Bacillus in the ability to colonize the epithelial surface.

[The effect of subinhibitory concentrations of antibiotics on the adhesion of enterobacteria]. / Vliianie subingibiruiushchikh kontsentratsii antibiotikov na adgeziiu énterobakterii.

It is impossible to determine rigidly a net result of the influence of antibiotics on the interaction between parasite and host cells, as many factors participating in this process are not studied. Adhesion of microorganisms is one of the essential mechanisms of the above interaction. Antibiotics with a different mechanism of action in the subinhibitory concentrations affecting viability of microbes either slightly or nowise have been studied for their effect on adhesion on a model of the intestine section of human embryos and experimental animals. Most of antibiotics influenced differently adhesion of the microorganisms, that also depended on the species attribution of the latter. The accelerated selection of resistance during a successive passage via the suggested adhesion system was observed. The data obtained elucidated certain mechanisms of the effect of antibiotics on the microbial populations at the initial phase of the infectious process and under the primary contamination of mucosa.

[The isolation of a pure culture of Proteus hauseri from associated bacteria]. / Vydelenie chistoi kul'tury Proteus hauseri iz assotsiatsii.

A simple method for isolation of P. vulgaris and P. mirabilis pure culture from associations with other microorganisms has been developed. Medium for inoculation of a bacterial culture suspected of an association contains glycerin and asparaginic acid. The suggested method is simple and highly effective, reproducible at any bacteriologic laboratory, and is particularly valuable for improving the quality of etiologic diagnosis of pyoseptic diseases.

[Sensitivity of Proteus mirabilis to drugs in the presence of human blood serum]. / Chuvstvitel'nost' P. Mirabilis k khimiopreparatam v prisutstvii syvorotki krovi cheloveka.

For rational antibiotic therapy of patients with persisting bacterial infections, the routine determination of antibiotic resistance in the microorganisms may be insufficient. In this case estimation of the total bactericidal activity of the antibacterial drugs and sera against the causative agents is required. It was shown experimentally that in the presence of human blood sera sensitivity of the P. mirabilis strains to benzylpenicillin, ampicillin, gentamicin, kanamycin and cephaloridin increased, the sensitivity to rifampicin varied and the sensitivity to chloramphenicol and nalidixic acid lowered. The quantitative indices of the sensitivity depended on the biological properties of the strains. The bactericidal activity of the human blood sera lowered under the action of nalidixic acid, chloramphenicol and rifampicin, with the concentrations of the antibacterial drugs being equal to those attained in the blood of patients during chemotherapy. A method for determination of the bactericidal activity of human blood sera in the presence of the antibacterial drugs with the use of P. mirabilis is described. The method is relatively simple and provides satisfactory coincidence of the results indicative of the nonspecific resistance of the blood. This allows the physician to choose the rational antibiotic therapy.