[Evaluation of the effectiveness of antibacterial substances in treating an experimental form of bubonic plague in monkeys]. / Otsenka éffektivnosti antibakterial'nykh preparatov pri lechenii éksperimental'noi bubonnoi formy chumy u obez'ian.

The modelling of glandular plague and selection of the conditions for estimating the efficacy of new antibacterials for the treatment of the infection were performed on hamadryads (baboons). The experiments showed that the average LD50 of the culture of a highly virulent strain of Yersinia pestis on its subcutaneous administration to the animals was 2089 viable microbes. In 18 per cent of the episodes the experimental glandular plague in the animals was complicated by secondary plague pneumonia. Subcutaneous administration of 2 x 10(7) viable microbial cell of the plague pathogen caused acute sepsis and the animal death. The treatment of the experimental glandular plague in the hamadryads demonstrated that new antibacterials such as amikacin, netilmicin, ceftriaxone, cefotaxime, ceftizoxime, doxycycline, rifampicin, ofloxacin and ciprofloxacin were not inferior in their efficacy to streptomycin and tetracycline successfully used in the therapy of patients with plague.

[Extrachromosomal genetic elements of Clostridium botulinum. II. Isolation and analysis of DNA from bacteriophages of Clostridium botulinum types C and A]. / Vnekhromosomnye geneticheskie élementy Clostridium botulinum. II. Vydelenie i analiz DNK bakteriofagov Clostridium botulinum tipov C i A.

The DNAs of bacteriophage c-st, known to realize the lysogenic conversion of toxinogenicity among C. botulinum types C and D strains, and the nucleic acid of a virulent mutant of bacteriophage CB propagated in type A C. botulinum cells were purified and examined. Heterogeneity of phage c-st preparations was observed during purification, manifesting by formation of several bands in isopiknic CsCl gradient during centrifuging. An extra nucleic acid fraction was detected in some DNA preparations of phage c-st; the origin of this fraction is discussed. Plasmid extrachromosomal elements were for the first time found in the cells of nontoxigenic type C C. botulinum A02 strain, known as the indicator for c-st phage. The sensitivity of phage c-st DNA to 25 restriction endonucleases was examined. Analysis of the results of restriction analysis of c-st and CB phage DNAs and plasmid nucleic acids, revealed earlier in type A C. botulinum strains, disclosed several DNA modification enzymes with different recognition sites in type C C. botulinum. At least two of these activities are not found in type A strains. According to restriction analysis, total size of phage c-st DNA is about 160 kbp and of phage CB DNA 35 kbp. Individual EcoRI and HindIII restricts of phage c-st DNA, containing the initial site of botulinum toxin CI gene, were recognized by radioisotope labeled oligonucleotide probe Enzyme immunoassay revealed slight expression of the N-terminal region of bntc I gene in E. coli recombinant variants. These data can be used in further investigation of C. botulinum genetics.

[Combined (associated) vaccination against quarantinable infections]. / Kompleksnaia (assotsiirovannaia) vaktsinatsiia protiv karantinnykh infektsii.

The presence of several active foci of infection of different etiology is an indication for complex (combined) immunization against these diseases. The scheme of complex (combined) immunization against plague, cholera and yellow fever has been experimentally substantiated and successfully tested on volunteers.

[The safety of the jet (needle-free) injection]. / K voprosu o bezopasnosti struinoi (bezygol'noi) in''ektsii.

The analysis of literature doesn't give strong confirmation that jet injection could provoke the transmission of the infection. Nevertheless such infection is possible because of retrograde flow of vaccine preparation which just has mixed with tissue liquid of a previous patient or taking into account a continuous contact of an injector head with patient's skin during injection. The design of the injector head has a certain significance on this matter. These risk factors can be eliminated by strict observation of rules for handling these instruments. It's necessary to conduct additional experimental researches to prove or refute the safety of jet injections.

[Extrachromosomal genetic elements of Clostridium botulinum. I. Plasmids of toxigenic and atoxigenic strains of Clostridium botulinum type A]. / Vnekhromosomnye geneticheskie élementy Clostridium botulinum. I. Plazmidy toksigennykh i atoksigennykh shtammov Clostridium botulinum tipa A.

Plasmid profiles in fifteen toxigenic and six nontoxigenic strains of Clostridium botulinum type A were investigated. The electrophoretic patterns of nucleic acids from the bacterial lysates were shown to vary in relation to the mode of bacterial cells lysis and the stage of microbial population growth. Two toxigenic strains harbour a unique 3.9 MD plasmid, five strains have a plasmid of about 6 Md and seven other strains carry an 11.5 Md plasmid. The nontoxigenic derivatives of two toxigenic strains harbouring a 6 Md plasmid have lost this extrachromosomal element. The analysis of the derivatives has not indicated the 6 Md plasmid to be connected with bacteriocin production or antibiotic resistance in Clostridium botulinum. Nontoxigenic variants of three other strains possess an 11.5 Md plasmid similar to their toxigenic parents' one. One of the studied toxigenic strains harboured no plasmids, as well as its nontoxigenic derivative. The functions of all studied plasmids remain unknown. Physical maps of the 11.5 and 6 Md plasmids were constructed on the basis of restriction analysis. The obtained results can be used for identification and differentiation of Clostridium botulinum strains and in further molecular biological experiments with this organism.

[The adaptation of the human immune system during an ecological disaster]. / K probleme adaptatsii immunnoi sistemy cheloveka pri ékologicheskoi katastrofe.

This article studies the adaptative mechanisms of the immune system of servicemen in the Aral Sea region in response to the influence of unfavourable xenobiotic factors of the environment. The greatest homeostatic shifts were disclosed in servicemen of the 2nd and the 4th periods of service (6 months and 2 years of active duty correspondingly). Precisely these periods of selective service have the highest infectivity index. It is recommended to measure the volume of catabolic products of cell receptors (P-proteins) in order to obtain an integral index which could characterize the adaptative mechanisms of the immune system during the screening of servicemen in the conditions of unfavourable environment.

[Connection of outer membrane protein composition in Yersinia pestis cells with intrinsic plasmids]. / Sviaz' belkovogo sostava naruzhnykh membran kletok Yersinia pestis s nositel'stvom sobstvennykh plazmid.

A set of isogenic derivatives of Yersinia pestis EV strain was obtained including the variants harbouring the different compositions of Yersinia own plasmids. The protein profiles of outer membranes of the set of strains were defined. The polyacrylamide gel electrophoresis has shown the small 6.1 Md plasmid to code an outer membrane protein with mol mass 29 kDa, different from pesticin I, while the heavy 60.0 Md plasmid encodes the 15-16 kDa polypeptide different from monomers of F1 and T-antigens of plague microbe.

[Localization of the structural gene for botulinum neurotoxin type A using synthetic DNA probe for neurotoxin light chain]. / Poisk lokalizatsii strukturnogo gena botulinicheskogo neirotoksina tipa A s ispol'zovaniem sinteticheskogo DNK-zonda k legkoi tsepi neirotoksina.

To obtain the information on the genetic control of toxin production in the botulism causative agents, the oligonucleotides were synthesized as the molecular probes by translation of the amino acid sequence of the botulinic type A neurotoxin. The optimal conditions for hybridization of botulinic DNA with the synthetic DNA probes were determined and the probes specificity was demonstrated. The DNA fragments homologous to the probes used were shown to belong to bacterial genome, but not to bacteriophage one.

[Experience using fraction I of the plague microbe for revaccinating experimental animals]. / Opyt ispol'zovaniia fraktsii I chumnogo mikroba dlia revaktsinatsii éksperimental'nykh zhivotnykh.

Experiments on guinea pigs have shown that a pronounced revaccination effect develops in the animals receiving the booster injection of fraction I of Pasteurella pestis 1.5--4 months after the primary immunization with live plague vaccine, while the booster injection of live plague vaccine produces a low revaccination effect due to the fact that this vaccine is badly adapted in the body after the primary immunization.

[Experimental protective of fraction I of the plague microbe]. / Protektivnye svoistva fraktsii I chumnogo mikroba v éksperimente.

The immunogenic properties of the freeze-dried preparation of fraction I tisolated from the culture of avirulent Pasteurella pestis strain were studied in experiments on hamadryas baboons, guinea-pigs and white mice. The preparation was found to have a pronounced protective effect in hamadryas baboons and white mice, especially when the preparation was used in mixture with incomplete Freund adjuvant. In hamadryas baboons resistance to infection was shown to correlate with hemagglutionation antibody titres.

[Assessment of the effectiveness of different methoods of immunization with live plague vaccine EB in aerosol infections]. / Otsenka éffektivnosti razlichnykh metodov immunizatsii chumnoi zhivoi vaktsinoi EB pri aérozol'nom zarazhenii.

The work deals with the results of the comparative evaluation of the effectiveness of vaccines developed at the Sanitary Research Institute (Zagorsk) and the Mechnikov Research Institute for Vaccines and Sera (Moscow), as well as two methods of immunization against plague, by inhalation and subcutaneous injection, under the conditions of aerosol infection. The immunogenic effectiveness of both vaccines, when evaluated in terms of LD50, was shown to be approximately the same, but the animals immunized by the inhalation method with the vaccine developed at the Sanitary Research Institute proved to be less susceptible to infection than those immunized with the vaccine developed at the Mechnikov Research Institute for Vaccines and Sera in Moscow. After immunization by the inhalation method the vaccine developed at the Sanitary Research Institute rendered more effective protection (3- to 4-fold) against aerosol infection than after immunization by subcutaneous injection. The animals immunized by the inhalation method proved to be capable of surviving plague in the primary pneumonic form.

[Experience in using P. hamadryas for assessing the effectiveness of a peroral vaccination method against plague]. / Opyt ispol'zovaniia P. hamadryas dlia otsenki éffektivnosti peroral'nogo sposoba vaktsinatsii protiv chumy.

For the first time P. hamadryas were used for studying the effectiveness of oral immunization with dried live plague vaccine. Oral immunization was shown to produce morphological changes in the organs and tissues of the monkeys, which indicated the immune transformation of the organism. The challenge of the immunized animals with the infective agent introduced in aerosol showed the effectiveness of the inhalation and oral methods of immunization. P. hamadryas proved to be a suitable model for the evaluation of the effectiveness of oral vaccination. A more precise quantitative evaluation of the effectiveness of oral vaccination against plague requires further research.

[Stability of the immunogenic properties of plague vaccine strain EV, Research Institute of Epidemiology and Hygiene line, during long-term storage]. / Stabil'nost' immunogennykh svoistv chumnogo vaktsinnogo shtamma EV linii NIIEG v usloviiakh dlitel'nogo khraneniia.

The experiments in guinea pigs showed that the immunogenic properties of plague vaccine strain EV, line NIIEG, freeze-dried in 1947 and stored under vacuum without animalization, remained unchanged for 30 years. The subcultures prepared from this train showed, after three passages in guinea pigs, good immunogenic properties which preserved for 6--10 years (the term of observation). After 30-years storage the stock culture of strain EV, line NIIEG, can be used for the preparation of NIIS live plague vaccine.

[Further study of the effectiveness of oral immunization against plague in experiments on animals]. / Dal'neishee izuchenie éffektivnosti peroral'nogo sposoba immunizatsii protiv chumy v éksperimente na zhivotnykh.

It was shown in comparative experiments on guinea pigs that the oral method of immunization with plague vaccine was much less effective than the inhalation and subcutaneous. Guinea pigs were found to be a poor model for studying the efficacy of oral immunization with dry live plague vaccine rehydrated before use: with the use of this preparation the animals were 46 times less resistant to aerosol plague infection than in application of strain EB cultured in agar.