[The immunological properties of the main outer membrane protein of Legionella]. / Immunologicheskie svoistva glavnogo belka vneshnei membrany legionell.

The immunogenic properties of Legionella outer membrane main protein (OMMP) were studied by its effect on the proliferative activity of lymphocytes in guinea pigs. Preliminary immunization with OMMP activated only the specific and nonspecific proliferation of spleen cells. After infection with Legionella, secondary immune response developed in the spleen and lungs of previously immunized animals, in contrast to intact ones, and the nonspecific proliferative activity of lymphocytes in the spleen and lungs of previously immunized animals considerably increased. These results are indicative of the fact that Legionella OMMP, similarly to other Legionella antigens and immunomodulators, may be used for the formation of protective immunity.

[The protective properties of different Legionella antigens in experimental Legionella infection]. / Izuchenie protektivnykh svoistv razlichnykh antigenov legionell pri éksperimental'noi legionelleznoi infektsii.

The protective properties of Legionella antigenic preparations were studied on guinea pigs with experimental Legionella infection. Preliminary immunization of guinea pigs with serotypic antigen, cytolysin, as well as live or formalin-treated Legionella cells, did not protect the animals from the subsequent aerogenic infection with 10(5) colony-forming units of virulent L. pneumophila. Immunization with the main outer membrane protein ensured the survival of 70% of the animals and inhibited the proliferation of the infective agent in the lungs of guinea pigs subjected to aerogenic infection with 10(5) colony-forming units of virulent L. pneumophila. The data obtained in this study indicate that the main outer membrane protein of L. pneumophila is capable of stimulating protective immunity.

[The role of R plasmids in the resistance of bacteria in air]. / Rol' R-plazmid v rezistentnosti bakterii v vozdukhe.

The study of Escherichia coli J 53, used as a model, has revealed that some R plasmids isolated from Serratia marcescens and Klebsiella pneumoniae, found to be the cause of the outbreak of hospital infection, ensure, besides multiple drug resistance, also their viability in the air.

[Role of the lipid peroxidation system of Escherichia coli cells in maintaining their viability in air]. / Rol' sistemy perekisnogo okisleniia lipidov kletok Escherichia coli v obespechenii ikh zhiznesposobnosti v vozdukhe.

The study of 6 E. coli strains differing in their capacity for survival in the air has revealed that the physicochemical characteristics of lipids in microbial cells, such as antioxidizing activity, the concentration of peroxidation products, the content of lipids and their capacity for oxidation, are interrelated, which confirms the existence of the system regulating the peroxidation of lipids in prokaryotic cells, similar to the system regulating lipid peroxidation in eukaryotic cells. The capacity of cells for survival in the air has been shown to depend on the physicochemical state of lipids in cellular membranes.

[Relation of the stability of microbial cells in air to their phospholipid composition]. / Vzaimosviaz' ustoichivosti mikrobnykh kletok v vozdukhe s ikh fosfolipidnym sostavom.

The phospholipid composition of 8 Escherichia coli strains differing in their capacity for survival in the air with a relative humidity of 30% has been studied. The study has revealed that, irrespective of the phase of growth and the nature of the culture medium, the capacity of E. coli cells for survival in the air is related to their phospholipid composition, this capacity being the higher, the greater the content of total phospholipids and cardiolipin and the lower the concentration of phosphatidyl glycerine.

[1 of the causes of a change in viability of Escherichia coli L1 in air]. / Ob odnoi iz prichin izmeneniia zhiznesposobnosti Escherichia coli L1 v vozdukhe.

The possibility of changing the fatty acid composition of lipids in E. coli strain BB 20-14 by the introduction of ready lipid vesicles obtained from other E. coli strains into the growth medium has been established. Using E. coli strain BB 20-14 as an example, the dependence of the viability of bacteria on their fatty acid composition has been demonstrated.

[Fatty acid composition of Escherichia coli cells and their viability in air]. / Zhirnokislotnyi sostav kletok Escherichia coli i ikh vyzhivaemost' v vozdukhe.

Experiments on E. coli used as a model have revealed that fatty-acid composition is one of the characteristics which determine the viability of bacteria in the air. The viability of microbial cells in the air has been shown to increase with the increase of the pool of cyclopropane acids and the palmitic acid/palmitoleic acid ratio in the cells, irrespective of their genotype and the phase of their growth.

[Role of lipid antioxidizing activity in ensuring the viability of microbial cells in air]. / Rol' antiokislitel'noi aktivnosti lipidov v obespechenii zhiznesposobnosti mikrobnykh kletok v vozdukhe.

The study made on various Escherichia coli strains used as experimental models has demonstrated that bacterial lipids possess pronounced antioxidizing activity playing an essential role in the viability of bacterial cells in the air. The content of natural antioxidants in E. coli lipids and their antiradical activity have been determined.

[The effect of aerosolization on the changes in major biological properties of the vaccine strain of Francisella tularensis]. / Vliianie aérozolirovaniia na izmenenie osnovnykh biologicheskikh svoistv vaktsinnogo shtamma Francisella tularensis.

The exposure of F. tularensis vaccine strain 15/10 in the form of aerosol for more than 10 minutes results in the decrease of its virulence, immunogenicity and the content of species-specific antigen and in the increase of the dissociation level. Proceeding from this fact, during aerosol immunization with this vaccine strain exposure must not exceed 5 minutes for unstabilized aerosol and 10 minutes for aerosol stabilized with 5% glycerin. Under these conditions the properties of F. tularensis strain 15/10 are retained practically on the initial level.

[Role of PSD2 and GPS A20 genes in lethal processes in Escherichia coli found in the air]. / Rol' genov PSD2 i GPS A20 v letal'nykh protsessakh Escherichia coli, nakhodiashchikhsia v vozdukhe.

Comparative experiments on auxotrophic E. coli grown in rich nutrient L-broth have demonstrated that the influence of genes psd 2 and gps A 20 responsible for the synthesis of phospholipids in the bacterial membranes on the viability of the cells is unessential. The cultivation of strain BB 20-14 in a minimal E medium with different glycerophosphate admixtures has shown that the decrease of phospholipid content in the cells to one-third of the original level leads to a considerable change in the viability of the cells in the air.

[Method of selecting Escherichia coli resistant and sensitive to aerosolization]. / Metod selektsii rezistentnykh i chuvstvitel'nykh k aérozolirovaniiu Escherichia coli.

The study made on E. coli used as a model has indicated that the selection of clones, resistant or sensitive to aerosol dispersion, can be carried out by storing the freeze-dried cultures of these clones in humid air for 2.5 hours.

[Analysis of the potential for restoring E. coli cells, aerosolized in 30% relative humidity, by systems that repair UV damage]. / Analiz vozmozhnosti vosstanovleniia kletok E. coli, aérozolirovannykh v usloviiakh 30% otnositel'noi vlazhnosti, sistemami, vosstanavlivaiushchimi UF-povrezhdeniia.

The mutants, defective due to a complex of damages caused by UV radiation, are considerably more sensitive to aerosol dispersal under conditions of 30% relative humidity than their parent strains. The sensitivity of bacteria to dispersal by aerosol, equally increasing in case of mutations in any of the tested reparative genes, is not linked with their incapability to repair DNA damages, but should be rather considered as a pleiotropic effect. Strains E. coli K12 are somewhat more sensitive to aerosol dispersal than E. coli B when sprayed on fiberglass under conditions of 30% relative humidity.

[Technic of studying microorganism viability in a simulated aerosol state on fiberglass microfilaments]. / Metodika izucheniia zhiznesposobnosti mikroorganizmov v imitirovannom aérozol'nom sostoianii na mikronitiakh iz steklovolokna.

A specially developed method of studying the viability of microorganisms in the simulated aerosol state on glass microfibers was used to show that the survival rate of E. coli and F. tularensis on fiber-glass spheres was similar to that in true aerosol, as observed in a static aerosol chamber. The proposed method allows to study the viability of microbial cells after prolonged existence in aerosol under any environmental condition both in open spaces and closed rooms.