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Iu V Anan'ina

Publications and source records attributed to Iu V Anan'ina.

At least 19 recordsLinked to original sources

[Analysis of genomic polymorphism in leptospira by polymerase chain reaction with random primers].

A test system for genetic typing of Leptospirae is developed, based on the polymerase chain reaction (PCR) with arbitrary primers. Thirteen strains of 4 Leptospira species were examined: L. interrogans, L. parva, L. illini, and L. inadai. Analysis of polymorphism of amplicon length (PAL) by the PCR with short Sh1 and Sh2 primers revealed genotypical differences at the inter- and intraspecias levels, as well as at the subserovar level. PAL of L. interrogans strains Rga and M-20, serovars icterohaemorrhagiae and copenhageni, were identical both with Sh1 and Sh2 primers. Moreover, PCR with Sh2 primer showed genotypical similarity between strains Moscow V and M. oeconomus, serovar grippotyphosa of the same serogroup. Analysis of PAL by the PCR with long Lgn1 and Lgn2 primers showed similar results. Analysis of the PAL values obtained by the PCR with all primers permitted us to differentiate 9 L. interrogans strains into 8 PAL genotypes and identify a different degree of genotypical relation between strains of different serovars of this species. Complete genotypical relationship between strains L. inadai N 10 and EMJH 86 (serovar lyme) was confirmed by the new test system. Therefore, PCR-based test system with different primers can be used to differentiate between closely related Leptospira strains and to investigate the genotypical relationships between the strains at the intra- and interspecies and inter- and subserovar levels.

DNA Primers↗

[Development of polymerase chain reaction-based test systems for detecting leptospira in polytypical leptospirosis foci].

Two highly sensitive test systems G and B, based on the polymerase chain reaction, were developed for indication of pathogenic Leptospira interrogans, including the serovariants appearing during outbreaks in polytypical foci of leptospirosis in the tropical zone of China. These test systems can be used for rapid diagnosis of leptospirosis in humans in foci with different etiological structure.

China↗

[A small-mammal study in the northeastern Kara Kum for leptospirosis infectivity].

Search for natural foci of leptospirosis was carried out in 1987-1989 in humid biotopes of Tashauz Province, Turkmenistan. Such potential carriers of leptospirosis as house mice (Mus musculus) and tamarisk gerbils (Meriones tamariscinus) are widely spread in this area, and the size of their population can amount to great numbers. The sharpest fluctuations in the population size are characteristic of house mice inhabiting the shores of water collecting ponds and lakes in the regions of minimally used pastures. A moderate number of house mice was registered in spring and autumn at the area of irrigated agriculture. Only here and only in autumn a faint epizootic manifestation of the natural focus of L. grippotyphosa infection in house mice was registered for the first time in Turkmenistan. The titers in mouse blood sera, determined in the microagglutination test and the Leptospira lysis test, were 1:20 to 1:200. According to the data on the humidity and pH of the soil in the vicinity of irrigated fields, spring and summer months may be regarded as the most favorable period for the survival of leptospires in the environment. The probability of the aggravation of the epizootic situation seems to increase when irrigated fields adjoin pastures of are temporarily used as grazing ground for cattle.

Agriculture↗

[The genomic fingerprinting of the causative agents of sapronoses].

The genome polymorphism of the causative agents of sapronoses (Vibrio cholerae, Legionella and Leptospira) has been studied. The use of the method of genome fingerprinting [correction of dactyloscopy] has been shown to permit the differentiation of closely related strains of such causative agents. The epidemically significant strains of the causative agents of sapronoses, isolated in different geographical regions, have been found to be genotypically related, i.e., they are probably of clonal origin. Avirulent and nontoxigenic strains are genotypically heterogeneous and differ both from one another and from epidemically significant strains. Using V. cholerae as an example, the hypothesis of the appearance of potentially dangerous variants at the epidemic period in the absence of their release at the period between epidemics is considered.

DNA Fingerprinting↗

[Leptospirosis].

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Agricultural Workers' Diseases↗

[The improvement of immunobiological preparations against leptospirosis. An experimental study of a new concentrated purified vaccine against icterohemorrhagic leptospirosis for human immunization].

The findings of the study of immunological structure of the population in regions endemic for leptospirosis indicate that the immune status of humans makes it impossible to obtain titrated blood sera for the preparation of antileptospirosis immunoglobulin. The data obtained in the study of the immunobiological properties of a new concentrated vaccine against icterohemorrhagic leptospirosis show the possibility of using this vaccine for the immunization of donors with the aim of obtaining blood sera to be used as raw material for the production of immunobiological preparations.

Animals↗

[The functioning of a drained natural focus of leptospirosis in a nonchernozem area].

The drainage of a natural focus of leptospirosis of the flood plain-swamp type, carried out over the period of 15 years, has led to changes in the species structure of small mammals and to an increase in the number of Leptospira-carrying species. Nevertheless, like before drainage, the prevalent species and the main carrier of leptospires is still the root vole (Microtus oeconomus Pallas). The intensity of the epizootic process among small mammals at the final stage of drainage has proved to be similar to that at the initial stage. At the same time the cultivated fields created on the drained territory of the natural focus abound, by the time of harvesting, with small mammals among whom the intensive epizootic process takes place.

Agriculture↗

[The noncorrespondence of the geographic ranges of the host and the causative agent].

For the first time the experimental and field studies of Leptospira infections, carried out over the period of 6 years, have revealed that the habitat of striped field mice (Apodemus agrarius Pallas 1778) serving as a host for Leptospira pomona, serovar mozdok, is much wider than the habitat of the infective agent proper. The presence of an animal species highly sensitive to a definite leptospiral serovar and serving as its reservoir at a given locality cannot be regarded as a proof of the presence of the epizootic process without bacteriological confirmation. But, in the absence of homologous Leptospira carriage, intensive leptospiral seroconversion can be attributed to a population other than that of the host.

Animals↗

[Populations of pathogenic Leptospira of varying virulence in nature].

The study of geographically remote populations of Norway rats (Rattus norvegicus) revealed that in one of these populations a highly virulent population of Leptospira copenhageni, serogroup icterohaemorrhagiae, and in another population of rats a faintly virulent population of these microorganisms circulated simultaneously. At the same time in vitro experiments with Leptospira cultures showed the absence of the constant probability of sharp changes in the level of their virulence in time.

Animals↗

[Differences in the susceptibility of field mice from the Altai Territory and Moscow Province to Leptospira of serovar mozdok and serogroup Pomona].

Adult striped field mice (Apodemus agrarius) caught in the Altai region proved to be insusceptible to experimental infection when inoculated with Leptospira of serovar mozdok, serogroup Pomona. In pregnant females, though infected with this organism, no leptospiruria was observed. At the same time nonpubescent animals became Leptospira carriers, females becoming carriers 4.5 times more frequently than males. The formation of antibodies to Leptospira in the test rodents was poorly pronounced and did not depend on their sex, age, physiological state and the presence of renal leptospirosis. But all adult striped field mice belonging to the population of the Moscow region became Leptospira carriers in such experiments.

Aging↗

[Sensitivity of different morphological variants of Leptospira to the leptospirocidal activity of normal animal sera].

The leptospirocidal activity of normal animal sera with respect to 23 Leptospira strains was experimentally studied in vitro. 91.3% of the strains under study proved to be sensitive to the lytic action of cattle serum and 86.9%, to sheep serum. The uncinate variants of the pathogenic strains showed resistance to the action of the above sera, and their nonuncinate analogs were subject to agglutination with subsequent lysis, similarly to saprophytes.

Animals↗

[Etiological structure of icterohemorrhagic leptospirosis in gray rats (Rattus norvegicus)].

In 93 Leptospira strains isolated from Norwegian rats serovar determination was made. As a result, leptospires circulating among Norwegian rats were found to belong mainly to serovar copenhageni, group Icterohaemorrhagiae, while leptospires of serovar icterohaemorrhagiae, even if occurring, were found only in the animals inhabiting pigsties. Leptospirosis epizooty among rats, caused by L. icterohaemorrhagiae, took its course independently of leptospirosis epizooty among mice, caused by L. hebdomadis, and simultaneously with it.

Animals↗

[Bactericidal activity of normal sera from various animal species against pathogenic and saprophytic leptospires].

The leptospirocidal activity of 5 animal species against L. interrogans, L. biflexa and L. kazachstanica I and II, belonging to different serogroups and serovars, was studied. Cattle and sheep sera had no lytic effect on 36.9-40.1% of pathogenic Leptospira strains, but other pathogenic strains, as well as saprophytes, were lyzed by these sera. L. pomona and L. grippotyphosa exhibited high resistance to cattle serum, the latter being also resistant to sheep serum.

Animals↗

[The evaluation of the reactogenicity and immunogenic activity of a new concentrated inactivated leptospirosis vaccine].

In the controlled field trial the reactogenicity, safety and antigenic activity of a new concentrated inactivated leptospirosis vaccine after its administration in one and two injections of 0.5 ml were studied in comparison with those of the existing commercial vaccine, introduced in two injections in doses of 2.0 and 2.5 ml. The new experimental vaccine exhibited low reactogenicity and was found to be safe and highly immunogenic when introduced in a single injection of 0.5 ml. As shown in this trial, the immunogenic characteristics of immunization made in a single injection were not inferior than those obtained as the result of immunization made in two injections, yielding high percentage of seroconversions (89.8% to 98.3%) with respect to 4 Leptospira serogroups and leading to the production of the protective titers of corresponding antibodies. The existing commercial vaccine was inferior to the experimental one in antigenic activity (the frequency of seroconversions, antibody titers). The results of the trial make it possible to recommend the experimental concentrated leptospirosis vaccine for use in medical practice in a dose of 0.5 ml introduced in a single injection.

Adolescent↗

[Bacterial zoonoses with natural focality: current trends in epidemic manifestation].

Current trends in epidemic manifestation of some bacterial zoonoses with natural focality and their role in human infectious pathology have been reviewed and analyzed. Update information on the etiological agents of "emerging" and "re-emerging" infections--Astrakhan spotted fever, bartonellosis, ixodes tick-borne borrelioses, monocytic erhrlichiosis and canine brucellosis, recently isolated on the territory of Russia, is presented. The main factors at play in the process of urbanization of bacterial zoonoses are discussed.

Animals↗

[Gene diagnostics of acute persistent Leptospira infection].

The results of clinical trials carried out in different foci have demonstrated high diagnostic value of analysis made with the use of the polymerase chain reaction (PCR) at early stages of Leptospira infection caused by infective agents of the serogroups Grippotyphosa, Canicola and Icterohaemorrhagiae. The possibility of leptospiremia lasting considerably longer than heretofore believed to be possible, as well as the persistence of leptospires in the liquor of patients after the acute phase of the disease is over, i.e. during the early and late convalescence periods, has been shown. This is indicative of good prospects of using the PCR analysis not only for early rapid diagnostics of Leptospira infections, but also for controlling the course of the infection, for prognosticating early and late complications of the disease, as well the mechanisms of pathogenesis.

Acute Disease↗

[A new methodological approach for leptospira persistence studies in case of mixed leptospirosis].

A new methodical approach for Leptospira persistence studies in case of mixed leptospirosis, based on the use of PCR test systems with different taxonomic specificity for the indication and identification of leptospires, was developed. Two PCR test systems (G and B) were used in experiments on BALB/c white mice to study patterns of the development of mixed infection caused by leptospires of serovar poi (genomospecies L. borgpeterseni) and grippotyphosa (genomospecies L. kirschneri). The conclusion was made of good prospects of this method application in studies on symbiotic relationships of leptospires both in vivo and in vitro.

Animals↗