[A simple biological method for the fast identification of antibiotics]. / Prostoi sposob bystrogo opredeleniia antibiotikov biologicheskim metodom.

A method used to determine the quantitative and qualitative determination of antibiotics in blood, injury discharge, in human and animal urine as well as in foodstuffs (meat, milk and products made of them) is described. It is based on using obligate, thermophilic bacteria Bacillus stearothermophilus, strains KK BKM B-213OD and BKM B-718 with an optimum growth at 55-60 degrees C. Meso- and psychrophilic bacteria cannot grow at the above temperature, therefore, the studied non-sterile material does not need any preliminary thermal treatment prior to the indicator-strain, which is highly sensitive to all widely used antibiotics, is sown in the test-culture bacterial lawn.

[A new method for total complement activity analysis and its clinical significance]. / Novyi metod opredeleniia obshchei aktivnosti komplementa i ego klinicheskoe znachenie.

A test system consisting of a short-term suspension culture of mobile cells (bovine semen) is suggested for evaluating the complement activity. A simple and effective rapid method for evaluating the complement activity is based on the use of this system. Clinical application of this method helps evaluate the disease severity and predict the patient's condition in various diseases.

[The possibility of preserving the causative agent of plague in soil in resting (nonculturable) form]. / O vozmozhnosti sokhraneniia vozbuditelia chumy v pochve v pokoiashcheisia (nekul'tiviruemoi) forme.

The parallel study of soil specimens from the burrows of great gerbils, taken in the natural focus of infection at the period between epidemics, by the bacteriological method and with the use of polymerase chain reaction (PCR) demonstrated that, simultaneously with the negative results of inoculations into nutrient media, PCR revealed the presence of Y. pestis in 4 out of 72 soil specimens. The serological study (in the indirect hemagglutination test) revealed the presence of Y. pestis capsular antigen (fraction l) in 16 out of 75 soil specimens. The transition of Y. pestis (strain EV) into the nonculturable state was experimentally shown in sterile soil extract and in association with protozoa, algae and Euglena. Bacteriologically detected Y. pestis disappeared or were represented by a few cells after day 7, while PCR could register the presence of Y. pestis at a concentration of 10(4)-10(5) microbial cells per ml until the end of the term of observation (30 days). After the enrichment of the nutrient medium with fetal serum the complete reversion of Y. pestis nonculturable forms was observed: the concentration of bacteria grown on agar was 10(5) colony-forming units per ml. Transition into the nonculturable state was also observed in distilled water. The results of this investigation are discussed with special emphasis to the possibility of the preservation of Y. pestis in the nonculturable from during the period between epidemics as applied to the problem of plague epizootic.

[Isolation of monoclonal antibodies for the identification of strains of the causative agent of plague that do not contain a capsular antigen]. / Poluchenie monoklonal'nykh antitel dlia identifikatsii shtammov vozbuditelia chumy, ne soderzhashchikh kapsul'nogo antigena.

In most cases the immunological identification of Y. pestis strains is based on the use of capsular antigen as an immunological marker. However, there are Y. pestis strains without capsular antigen. For the immunological identification of such strains, homogeneous antigen with a molecular weight of 43 KD has been isolated and monoclonal antibodies to it have been obtained. The enzyme-linked immunosorbent assay, carried out with the use of these monoclonal antibodies and intended for the detection of antigen with a molecular weight of 43 KD, has been developed. The sensitivity of the assay is about 10 ng/ml.

[Isolation of high-affinity antibodies from hyperimmune serum]. / Vydelenie vysokoaffinnykh antitel iz giperimmunnoi syvorotki.

A group of high-affinity antibodies has been isolated from horse hyperimmune antiplague serum with the use of antigenic immunosorbent. High-affinity antibodies have proved to be homogeneous, which is indicated by the rectilinear character of the graph of the inverse values of the free antigen concentration.

[Theoretic scheme of immunoenzyme analysis (the "sandwich" variant)]. / Teoreticheskaia skhema immunofermentnogo analiza (variant "sandvich").

The sandwich variant of the enzyme-linked immunosorbent assay (ELISA) is a simple serological reaction of three components, and the antigen-antibody interaction follows the law of active masses. To increase the sensitivity of ELISA with respect to the antigen, the plates should be sensitized with moderate concentrations of antibodies and the confugate should be introduced at relatively low concentrations. To increase the activity of the conjugate, the plates should be sensitized with high concentrations of antibodies, but in this case the sensitivity of ELISA will not be high.

[A new method of determining antibody heterogenicity (among them, monoclonal) by affinity]. / Novyí sposob opredeleniia geterogennosti antitel (v tom chisle monoklonal'nykh) po affinitetu.

In this assay, cellulose antigenic immunosorbent was used as solid phase and preparations of polyclonal and monoclonal bivalent antibodies as antibodies. The new method is based on the assumption that definite relationship exists between some of free molecules and some of bound active centers of antibodies in the process of the interaction of antibodies and antigenic immunosorbent. Groups of antibodies with different affinity were detected in hyperimmune horse serum, in immune mouse serum and in the monoclonal preparation, which, on the one hand, confirms our earlier data and, on the other hand, demonstrates the possibility of using the new method for determination of antibody affinity.

[Filament and cellulose acetate columns for affinity chromatography]. / Nitchatye i atsetattselliuloznye "kolonki" dlia affinnoi khromatografii.

Single-use filament columns for affinity chromatography are described. Antigenic filaments for the isolation of pure antibodies have proved to be much more effective than antibody filaments for the isolation of antigens. Nitrocellulose filter has been employed for the preparation of paper columns that may be used for the isolation of pure antibodies 8-10 times.

[The use of thermal analysis in developing chemical tests of sterilization]. / Ispol'zovanie termicheskogo analiza dlia razrabotki khimicheskikh testov sterilizatsii.

A number of chemicals have been examined to find out whether they can be employed to test the temperature regimens of vapor and hot-air sterilization methods. Test kits for various temperature ranges and different sterilization modes have been selected. It is advisable that stains be used in tests (except the sulfur one) to control vapor (but not hot-air) sterilization.

[Detection of plague microbes in fleas using immunoenzyme technics and monoclonal antibodies]. / Obnaruzhenie chumnogo mikroba v organizme blokh s primeneniem immunofermentnogo analiza i monoklonal'nykh antitel.

The paper presents the results of immunoassays for indication of pest causative agents in fleas, this method being compared to the classical and bacteriological methods. Experiments proved the feasibility of indication of pest causative agents in fleas by immunoassays. Immunoassays were found to excel the classical and bacteriological ones.

[Immunoenzyme analysis using paper disks]. / Immunofermentnyi analiz s ispol'zovaniem bumazhnykh diskov.

Filter paper discs have been used in the enzyme immunoassay (EIA) as solid phase instead of polystyrene plates. The use of paper discs has made it possible to achieve a multiple increase in the sensitivity of sandwich EIA, thus permitting the detection of Yersinia pestis capsular antigen at a concentration of 0.4 ng/ml. Paper discs can be used not only for the sorption of antigen and antibodies, but also for the affinity purification of preparations.

[Mechanism of the interaction of chloramine with Pseudomonas aeruginosa]. / K mekhanizmu vzaimodeistviia khloramina s Pseudomonas aeruginosa.

The disinfecting effect of chloramine on P. aeruginosa depends on the concentration of this disinfecting agent, the concentration of P. aeruginosa and the period of exposure, with consideration for the time of attaining equilibrium between the concentration of chloramine and P. aeruginosa, affinity between the disinfectant and bacterial cells, the number of chloramine-binding sites on a bacterial cell, the admixture of organic substances, pH and other environmental characteristics. The interaction of chloramine and P. aeruginosa can be subdivided into two stages: (1) the binding of the disinfectant by bacterial cells and (2) the death of the microbes. The mathematical description of the process of disinfection requires that the main characteristics be expressed in molecular parameters and the time factor be correlated with the terms of attaining the equilibrium for free and bound chloramine. The average number of binding sites for chloramine on a bacterial cell and the affinity constant of chloramine to binding sites have been estimated.

[Antigenuria in plague-infected great gerbils]. / Antigenuriia u zarazhennykh chumoi bol'shikh peschanok.

In the urine of plague-infected great gerbils Yersinia pestis capsular antigen was detected by means of diagnostic preparations, both commercial and experimental (based on monoclonal antibodies). The antigen was detected in many urine samples taken from the animals over a prolonged period. The incidence and duration of antigenuria were found to be related to the survival time of great gerbils after infection and the level of antibodies in their blood. The number of animals with antigenuria markedly exceeded the number of animals from which Y. pestis was isolated, especially at a later period after infection. Examinations of urine samples from live great gerbils trapped in natural foci appears to be a method more effective in epizootiological survey than the bacteriological analysis of the animals.

[Serological reaction systems using enzyme-labelled immunospecific reagents]. / Sistemy serologicheskikh reaktsii s ispol'zovaniem immunospetsificheskikh reagentov, mechennykh fermentom.

Different serological test systems, based on the use of enzyme-labeled immunospecific reagents and intended for testing the material under study for the presence of Yersinia pestis capsular antigen and antibodies to it, are described. Comparative data on the evaluation of their sensitivity to the antigen and antibodies to it in different schemes of enzyme immunoassays (EIA) are presented. As shown in this investigation, EIA systems for the detection of the antigen and antibodies to it can comprise, at the minimum, the following set of reagents: monoclonal antibodies to the capsular antigen, staphylococcal protein A, and the conjugates of the capsular antigen and monoclonal antibodies with horse-radish peroxidase. The authors have come to the conclusion that the use of the serological test systems can essentially increase the reliability of the assay of any individual sample by EIA techniques.