[The immune-enzyme techniques of analysis in diagnostic of cholera.]

The optimal conditions of arrangement of direct alternative of flatbed enzyme-linked immunosorbent assay and dot-immunoanalysis with application of monoclonal peroxidase conjugates for express identification of comma bacillus of serogroups O1 and O139 both in hospital and field conditions without device support. The direct technique enzyme-linked immunosorbent assay in flatbed alternative shortens time of analysis up to 70-80 minutes and in case of dot enzyme-linked immunosorbent assay on membrane - up to 70-90 minutes. It is established that in case of analysis in conditions of room temperature (20-25 oC) sensitivity of techniques remains at initial level.

[The application of monoclonal peroxidase conjugates to identify comma bacillus of serum groups 01 and 0139 in the reaction of dot-immune analysis].

The source of monoclonal antibodies was chosen the cultural fluid of hybridoma-producers deposited in the specialized collection of cell cultures of vertebrates (St. Petersburg) with numbers RKKK(P) 386D and RKKK(P) 674D. The specific immunoglobulin (Ig) from cultural fluid was concentrated by precipitation with saturated solution of ammonium sulfate. The scheme of obtaining monoclonal antibodies included activation of peroxidase, conjugation of activated peroxidase with Ig, removal of unbounded proteins, storage and control. The preservation of activity of conjugates was supported with BSA (10%) or glycerin (50%). The last on is preferable to be applied for this purpose. The test of monoclonal antibody-01 and monoclonal antibody-0139 of peroxidase conjugates with kit of strains of comma bacillus 01 and 0139 demonstrated their strict specificity because they interacted only with corresponding serum groups under absence of crossed reactions with representatives of geterologic microorganisms. The direct dot-immune analysis is carried out during 1.5 hour and its sensitivity is within the limits 105-106. The application of diagnostic monoclonal peroxidase conjugates 01, 0139 in laboratory practice can promote the increase of specificity of serologic analysis of cholera and saving time-frame of its application.

[Effect of plague "murine" toxin on activity of antioxidant system in cells of experimental animals].

AIM: To study nature of changes in components of glutathione disulfide system of experimental animals influenced by plague "murine" toxin. MATERIALS AND METHODS: Total glutathione level as well as levels of oxidated (G-SS-G) and reduced (GSH) forms of glutathione, activity of glutathione reductase and glutathione peroxidase in erythrocytes of Mongolian gerbils (Meriones unguiculatus), mice and guinea pigs were studied. RESULTS: Sharp decrease of reduced glutathione level as well as increase of oxidated glutathione level were observed in all experimental animal species after intraperitoneal administration of plague "murine" toxin. Changes in levels of GSH and G-SS-G were followed with decrease of total glutathione level. Activity of glutathione peroxidase was decreased in mice and Mongolian gerbils. There was increase of activity of this enzyme in guinea pigs. Level of glutathione reductase was decreased in all studied animals. CONCLUSION: Performed studies allow to hypothesize that oxidation of thiolic functional groups in organisms of animals as a result of H2O2 generation has important role during plague intoxication (administration of sublethal doses of plague "murine" toxin).

[Morphology and enzyme activity of nonculturable forms of Vibrio cholerae]. / Morfologiia i fermentativnaia aktivnost' nekul'tiviruemykh form cholernykh vibrionov.

The transition of V. cholerae into the uncultivable state under experimental conditions was accompanied by gradual changes in their morphology, motility and metabolic activity. The vibrios took the oval form, lost their flagellum, motility and enzyme activity on diagnostic media. Dehydrogenase activity tested by reduction of triphenyl tetrazolium chloride, increased at the initial stages and dropped to the initial level or even lower by the end of the observation period (10 months). Similar dynamics was noted when the cytoplasmatic marker enzyme--ATPase activity was studied. Glucose catabolism in the uncultivable forms shifted towards glycolysis. During 1-2 months ctx and tcp genes could be detected in these forms by the PCR. The dynamics of the biological properties under study made it possible to find out the existence of 3 functionally different stages in the development of an uncultivable population.

[Iron assimilation by Yersinia pestis on iron-deficient media]. / Izuchenie assimiliatsii chumnym mikrobom zheleza v usloviiakh zhelezodefitsitnykh sred.

The growth of plague bacteria may be limited by the level of iron concentration in the nutrient medium. The virulent strains of the plague microbe possess the more pronounced mechanism of iron assimilation as compared to the vaccine strain. The iron ions are extracted by the virulent and vaccine strains only under the cell surface contact with the iron-saturated transferrin. The iron-sorbing function is peculiar to the plague microbe cell walls which is pronounced more strongly in the virulent strains.