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Basic Achievements of the Institute and Dependent Antiplague Stations

Epidemiology and epizootology:

  • The Transbaikalian natural plague focus has brought into a healthy state (human diseases are absent from 1931, epizootics are not revealed since 1971);
  • Gorno-Altaic and Tuva natural plague foci have been discovered, anti-epidemic conditions are provided in both foci;
  • Natural contamination of rodents 10 species, lagomorphs - 2 and predators 3 (a tarbagan, an Altay marmot, a long-tailed Siberian suslik, a Mongolian pika, a Daurian pika, a narrow-skulled vole, a flat-skulled vole, a Brandts vole, a gregarious vole, a Mongolian gerbil, a Siberian jerboa, an Asian hamster, a steppe polecat, a marbled polecat, an Alpine weasel), fleas - 29, louses - 2, Ixodes ticks - 2 species has been established;
  • A map of anthrax permanent locations in Eastern Siberia and Far East has been composed;
  • New tularemia foci in Western, Eastern Siberia and on the Far East have been revealed and investigated;
  • Brucellosis foci among reindeers (for the first time in Irkutsk and Kamchatka areas), marals, sika deers, yaks, infectious epididymitis among rams have been revealed;
  • For the first time the foci of infectious epididymitis among rams have been registered in Eastern Siberia;
  • Nineteen new natural leptospirosis foci have been revealed, these etiologic and biocenotic structures were studied, before unknown Leptospira variants were isolated;
  • Vibrio flora, specific patterns of Vibrio cholerae El Tor circulation in surface waters of Siberia and Far East and an ecological niche of vibrios in hydrobiocenosis are studied. Long-term (more than 25 years) persistence of Vibrio cholerae in surface waters was established as the evidence of its exclusive adaptable ability. Vibrio cholerae capacity to transform into non-cultivated state with preservation of antigenic determinants and virulence genes was demonstrated;
  • Basic epidemiological patterns and distribution of yersinioses caused by Yersinia pseudotuberculosis and Yersinia enterocolitica in Siberia and on the Far East are defined more exactly;
  • Wide searching investigations of natural focal infections at territories adjoining to Baikal-Amur Mainline (BAM) have been carried out, before unknown foci of tularemia, brucellosis, erysipeloid, listeriosis, pasterellosis, leptospirosis, Q-fever, tick-borne ricketsiosis of Northern Asia were discovered;
  • Informational analytical criteria and features are developed, on the basis of which the number of virus infections actual for sanitary protection of territories from importation and distribution of especially dangerous virus infections can be determined.

Microbiology and biochemistry

  • Yersinia pestis strains from Gorno-Altaic natural plague focus were isolated, studied and classified as independent subspecies - Y. pestis altaica and Y. pestis ulegeica. Taxonomy of Yersinia genus was defined more exactly;
  • For the first time Yersinia pestis plasmids with molecular weight 8 and 16 D were found;
  • Genotyping of Yersinia pestis strains from the Siberian natural plague foci was performed on the basis of DNA variable number of tandem repeats (VNTR) in locus (CAAA) n;
  • Possibility of virulence increase of the vaccine and Ulegey Yersinia pestis strains was proved by repeated passage through a Mongolian pika (Ochotona pricei);
  • Biological properties of Yersinia strains isolated in Siberia and on the Far East were characterized. Methods of differential diagnostics of Yersinia pseudotuberculosis and intestinal Yersinia strains were developed, new Y. pseudotuberculosis plasmidovars were found out;
  • Immunoenzyme (plague, cholera, tularemia, brucellosis, anthrax), immunofluorescent (anthrax), immunoerythroadsorption (brucellosis) methods, polymerase chain reaction (plague, brucellosis), dot-immunoassay (plague) were developed for detection of corresponding antigens and antibodies; plasmid and restriction analyses and DNA-DNA hybridization method were developed and practically introduced;
  • A new independent Brucella species, Brucella rangiferi isolated from reindeers was described. The opportunity of B. ovis transformation in S-form closely related to B. melitensis including virulence was demonstrated by repeated passage through guinea pigs;
  • Opportunity of cell wall protective property increase and its isolated polysaccharide-contained antigens was firstly demonstrated by the example of Brucella due to its conjugation with heterologous proteins;
  • Color, dry Brucella diagnosticum for R and R was constructed from B. abortus 19 corpuscular antigen in S-form and the opportunity of its application was shown in studying of human and animal blood sera;
  • A new method for isolation and purification of bacterial polysaccharides and protein lipopolysaccharide complexes using immobilized polymyxin B and nonionic detergents was developed. Immobilized subtilin suitability was demonstrated for casein hydrolysate preparation with the subsequent construction on their basis of nutrient media for diagnostics of especially dangerous infectious agents;
  • A Museum of live cultures has been created and is working hitherto. This collection contains over 5000 strains of I-IV pathogenicity groups including 1840 Yersinia pestis strains.

Virology

  • The new foci were revealed and tick-borne encephalitis (TBE) areal limits were defined more exactly in Eastern Siberia, on the Far East and Mongolia. For the first time the combined foci of both plague and TBE were discovered in Tuva Republic and Mongolia. An urban TBE focus was investigated and described;
  • The role of migrant and settled birds in ecology of TBE virus was investigated. Bats as the virus carrier were established. TBE virus transmission was experimentally demonstrated at flea blood sucking;
  • Heterogeneity of TBE virus (two subtypes) circulating in Pribaikalye was proved;
  • For the first time Aina/1448 strain of TBE virus recognized as the prototype of an independent Siberian subtype of TBE virus was isolated and studied. Its etiologic role in human acute and chronic TBE was demonstrated. Research works of this cycle and N. N. Kraminskaya, its scientific leader, have obtained world recognition;
  • For the first time arbovirus Inko was isolated in Pribaikalye and human cases were revealed. Infection foci caused by Californian encephalitis viruses were established. Natural foci of hemorrhagic fever with renal syndrome (HFRS), Batai, Geta, Western Nile viruses were confirmed in the Region. Peculiarities of Batai virus circulation were investigated;
  • Priority cycle on studying of Ebola and Marburg virus biological properties was carried out. Test-systems for detection of virus-specific antigens and antibodies were developed;
  • The reason of Baikal seal mass death was recognized. Morbillivirus as an etiologic factor was isolated and identified;
  • The unique collection of regional TBE virus strains, other viruses of I-II pathogenicity groups, morbillivirus was formed. A bank of human and animal blood sera was created and widen.

Prophylaxis and control measures

  • Highly effective live vaccine against tularemia was created under the direction and at direct participation of prof. N. A.Gaisky;
  • Conjunctival vaccination method against plague was developed;
  • A high immunogenic preparation conjugated with heterologous protein was created (together with researches from Rostov-on-Don Antiplague Institute) on the basis of Yersinia pestis cell membrane antigens;
  • A semisynthetic cholera vaccine with immunomodulating polyelectrolytes was constructed (together with the specialists from Moscow Institute of Immunology) on a basis of Vibrio cholerae deacetylated lipopolysaccharide. Technology of its preparation was developed;
  • Vaccinal preparation with experimental high protective properties was constructed on the basis of Bacillus anthracis cell walls, protein C and protective antigen;
  • Possibility of specific immunity increase by natural immunomodulators (arabinogalactane and its iron- and cobalt-containing derivatives) against plague and anthrax was shown;
  • Destruction methods for rodents, plague carriers (at Transbaikalie), and field disinsection technique (Tuva, Gornyi Altay) were developed and successfully approved in the Siberian natural foci;
  • Workers of the Institute and Stations have accepted an active participation in suppression of plague (Transbaikalie, ongolia, Chinese People's Republic), cholera (Central Asia, southern regions of the European Russia, Ukraine, a number of Siberian regions), tularemia (Volga region, Kirov area, Yakutia), brucellosis (Chita area, Tuva) outbreaks.

Production of medical immunobiological preparations

  • Production of several tens of bacterial preparations, antisera, nutrient media was developed. Last decade the cholera corpuscular vaccine, cholera vaccine (cholerogen-anatoxin + antigen ), tularemia, plague antiphagous, cholera agglutinating O, Inaba, Ogawa dry sera, nutrient media for Yersinia pestis cultivation, Vibrio cholerae isolation, Yersinia differentiation, nutrient basis for Francisella tularensis cultivation were developed;
  • Dry elective nutrient medium for Listeria isolation providing Listeria monocytogenes growth and inhibition of accessory microflora (Escherichia coli, Salmonella cholerae suis, Proteus vulgaris, Staphylococcus aureus) growth was constructed.

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