[Genomic polymorphism of the main subspecies of the plague agent strains].

Genomic fingerprinting analysis of plague agent strains of the main subspecies isolated in natural foci of various types in the Russian Federation and neighboring countries suggests their genetic polymorphism, while they are similar in phenotypic properties. The strains of the main subspecies, Y. pesis subsp. Pestis, fall into four genetic variants, each of them being associated with specific carrier species. The conserved genomic fingerprinting profile of each genovariant of Y. pesis subsp. Pestis strains ensures the suggested methodic approach to be promising for the intraspecies differentiation of plague agent strains (including atypical strains). Correlation of genovariants with carrier species permits their application for research into enzootic territories, where carrier change-over takes place.

[Comparative study of the diagnostic value of new cholera eltor bacteriophages ctx+, ctx-, and KhDF-3, 4, and 5]. / Sravnitel'noe izuchenoe diagnosticheskoi tsennosti novykh bakteriofagov kholernykh él'tor ctx+, ctx-, i KhDF-3, 4, 5]

The comparative evaluation of the diagnostic value of new cholera eltor bacteriophages ctx+ and ctx-, as well as monophages X[symbol: see text]-3, 4, 5, demonstrated their high activity and specificity. Using of these bacteriophages epidemic potential of 95% Vibrio cholerae eltor strains ctx+ and 84.5% of V. cholerae eltor stains ctx- was determined. Commercial monophages X[symbol: see text]-3, 4, 5 were inferior to bacteriophages ctx+ and ctx- in their diagnostic value: only 55% of strains having gene ctxAB were found to be epidemically dangerous, i.e. 45% of strains capable of causing the disease were not detected. On the basis of the results obtained in this investigation cholera eltor bacteriophages ctx+ and ctx- were recommended for introduction into practical use, while further production of cholera diagnostic monophages X[symbol: see text]-3, 4, 5 was recommended to be stopped.

[Genotyping Yersinia pestis strains from various natural foci]. / Genotipirovanie shtammov Yersinia pestis iz razlichnykh prirodnykh ochagov.

Seven genetic variants of Yersinia pestis were detected by finger-printing of 85 strains of this bacterium from natural foci by means of a BX probe. Variants of Y. pestis strains correlate with certain species of carriers.

[The comparative characteristics of the pathogenic action of Vibrio cholerae of the non-O1 group O139 serovar and of the O1 group on the intestinal APUD system of suckling rabbits]. / Sravnitel'naia kharakteristika patogennogo deistviia kholernykh vibrionov ne O1 gruppy O139 serovara i O1 gruppy na APUD-sistemu kishechnika krol'chat-sosunkov.

The comparative study of the enteropathogenic action of V. cholerae strains of group non-O1, serovar O139, and group O1 with different virulence on the APUD system of the intestine of suckling rabbits after intraenteral infection revealed that V. cholerae of group non-O1 induced inflammatory changes in the intestine and the pronounced toxic lesion of parenchymal organs. This was accompanied by a decrease in the number of apudocytes and an increase in the functional tension of the APUD system. After the infection of the animals with V. cholerae of group O1 changes in the APUD system and internal organs directly depended on the virulence of the microbes and the infective dose.

[Comparative study of the structure of some genetic probes used for typing Yersinia pestis strains]. / Sravnitel'noe izuchenie struktury nekotorykh geneticheskikh zondov, ispol'zuemykh dlia tipirovaniia shtammov Yersinia pestis.

A nucleotide sequence common for genetic probes used for detection and investigation of Y. pestis strains MK, IS100, and HRSIII was identified on the basis of restriction, hybridization, and computer analysis. This region of chromosomal DNA is a part of low-molecular BX-probe (about 170 bp) we have developed. The results of genomic fingerprinting of Y. pestis strains by the BX-probe are promising as regards its future utilization for typing the strains isolated in various endemic areas.

[An immunoenzyme test system for the identification of typical and atypical strains of the plague microbe]. / Immunofermentnaia test-sistema dlia identifikatsii tipichnykh i atipichnykh shtammov chumnogo mikroba.

The authors have developed the optimal variant of the enzyme immunoassay system that contains plague murine monoclonal and equine polyclonal immunoglobulins and identified all plague microbe strains at a high sensitivity (3.84 m.cl/ml). The cross reactivity of monoclonal antibodies with some pseudotuberculosis agent strains does not prevent from using the developed test system for laboratory diagnosis of plague, particularly while isolating atypical (capsule- or plasmid-free) variants of Y. pestis, taking into account parallel special diagnostic tests for pseudotuberculosis.

[Effect of plague microbe fraction 1 protein-polysaccharide complex and pure protein on metabolic parameters of macrophages]. / Vliianie belkovopolisakharidnogo kompleksa i chistogo belka fraktsii 1 chumnogo mikroba na metabolicheskie pokazateli makrofagov.

The investigation reveals different influence of the plague microbe's fraction 1 polysaccharide-protein complex and of it's purified protein on the 5'-nucleotidase activity and on the chemiluminescence response of peritoneal macrophages. Both of these metabolic indexes were found to be dependent on the dose of fraction 1 and duration of time till examination.