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A S Maramovich

Publications and source records attributed to A S Maramovich.

At least 19 recordsLinked to original sources

[Mode of sample preparation for pseudotuberculosis laboratory diagnosis by polymer chain reaction method].

A mode of feces sample preparation was developed for polymerase chain reaction (PCR) assay. It was based on alkaline treatment of the material. This treatment killed the most part of indigenous microflora, whereas Yersinia survived, because it was relatively resistant to alkaline. The mode was tested using human feces artificially contaminated with Yersinia pseudotuberculosis. Positive responses in samples containing 10(3)-10(8) microbial cells per ml were obtained by PCR assay with Yersi and Yers2, Invl and Inv2, YP3 and YP4 primers. Diagnostic efficiency of PCR for patients, small mammals, and washings from environmental objects was 4.75, 1.66, and 2.12 times higher than diagnostic efficiency of bacteriological analysis of these samples, respectively. Positive results in PCR were obtained at the day of the material collection and treatment, whereas Y. pseudotuberculosis was isolated only after 8-20 days. Positive samples in PCR and in bacteriological analysis were found to coincide. A brief scheme of the Y. pseudotuberculosis laboratory diagnosis is suggested. According to this scheme, target-oriented bacteriological assay is performed only in those samples, in which preliminary PCR assay after 1-3 days of incubation gave positive results of Y. pseudotuberculosis DNA detection.

Animals↗

[PCR-detection of markers for epidemiologically-significant strains of Vibrio cholerae 0139, isolated in Siberia].

Fourteen V. cholerae 0139 strains were isolated in 1996-1999 in Siberia from the Ob river (Novosibirsk) and bogs and lakes (Irkutsk). The strains were tested in PCR for the key virulence determinants (ctx AB, tcp, acf). The genomes lacked these elements, and therefore the strains were acknowledged avirulent. The results correlate completely with the data of phenotypical analysis, characterizing the pathogenic characteristics of isolated strains.

Base Sequence↗

[Strategies of adaptive changes in Vibrio cholerae in natural water reservoirs].

The currently available data on different variations in cholera vibrio habiting in water reservoirs are summarized. The pattern of variations of the main signs of vibrions is discussed in the context of "typical-atypical-inactive-resting (uncultivable) forms". Emphasis is placed on the reversible pattern and adaptive essence of variation whose basis is clonal and selective processes in the heterogeneous bacterial population. Possible populational mechanisms responsible for the development of epidemic types of cholera vibrions in the aqueous ecosystems as a prerequisite for human morbidity are discussed. The efficiency of ecological and molecular genetic studies for the epidemiology of cholera is recognized.

Adaptation, Physiological↗

[The epidemiological patterns of pseudotuberculosis in Khabarovsk Territory].

Materials on the epidemiological characterization of pseudotuberculosis at the Khabarovsk Territory taken as a whole and in individual settlements, as well as on the evaluation of epizootic situation in natural foci of infection and foci created by human activities, are presented. The results of laboratory studies of vegetables, washings from environmental objects, soil specimens, material taken from rodents are demonstrated and the characterization of the virulent properties of isolated Yersinia pseudotuberculosis strains is given. Two periods (1976-1982 and 1983-1989) were distinguished by their main epidemiological features. The most important feature of the second period is the shift of the seasonal morbidity rise to the middle of summer, which is explained by activation of the mechanism of transmission of this infection due to the supply of early vegetables infected in local vegetable stores. An essential role of wild and synanthropic Muridae as the reservoir of infection is shown; these rodents and the soil maintain the circulation of the infective agent accumulating in the most favorable habitat, vegetable stores. The regularities established in this work contribute to the improvement of epidemiological surveillance.

Animals↗

[Immunologic monitoring of leptospirosis in the Maritime Territory].

The epidemiological and epizootic situation in Leptospira infections at the Maritime [correction of Primorski] Territory is evaluated on the basis of complex studies carried out in 1984-1989. As revealed in these studies, cases of leptospirosis among humans have a sporadic character and are mainly registered among professional high risk groups of the population. In the immunological structure of persons covered by the survey L. hebdomadis, L. pomona and L. javanica prevail. The anthropourgic foci of leptospirosis caused by L. pomona are of the leading epidemiological importance. Swine serves as the main source of infection in these foci. The study revealed the epidemic danger of the natural foci of leptospirosis caused by L. grippotyphosa and L. javanica in rice fields where the decisive factors of leptospirosis proved to be reed voles and striped field mice serving as reservoirs of this infection, as well as the synanthropic foci of leptospirosis caused by L. hebdomadis with house mice serving as the main carriers.

Animals↗

[The toxin-producing capacity of populations of Vibrio cholerae of different origins].

As the result of the study of toxin formation in 165 V. eltor strains having different virulence, most of the virulent cultures have shown stable toxin production, though 5-10% of their colonies have proved to be nontoxigenic. In faintly virulent strains toxin production was found to be unstable, which is indicative of the heterogeneity of their population composition as regards their capacity for toxin formation. The population of avirulent strains consists mainly of nontoxigenic clones (95.7%).

Animals↗

[Lessons of cholera pandemic VII].

Basic epidemiological regularities of El-Tor Cholera during pandemic VII are described with differentiation of the four periods of its global spread and evaluation of the efficacy of therapeutic and preventive measures. The findings of studies into the ecology of the causative organism in the surface water basins testify to the possibility of its long-lasting existence in the saprophytic phase, which requires differentiation of the anti-cholera actions. The necessity of improvement of the global epidemiological control is substantiated.

Cholera↗

[Cholera in the Far East of Russia. Communication 1. Epidemiological characteristics of the outbreak of cholera El tor in Vladivostok].

The materials on the investigation of the outbreak cholera eltor in Vladivostok, caused by the import of infection from China. The leading role of the water route of transmission of this infection is shown due to the contamination of water sources with non-decontaminated sewage water. The complex of antiepidemic measures was carried out, which made it possible to arrest the spread of cholera and liquidate its foci.

Cholera↗

[Cholera in the Far East of Russia. Communication 2. Epidemiological characteristics of the outbreak of cholera El tor in Iuzhno-Sakhalinsk].

The outbreak of cholera eltor in Yuzhno-Sakhalinsk has been analyzed. The fact of the import of this infection from China and its transmission mainly by the water route due to the intensive contamination of environmental objects has been substantiated. The effective purification decontamination of sewage water plays decisive role on the system of anticholera measures. The conclusion on the necessity of increasing the effectiveness of measures for the sanitary protection of the territory has been made.

Cholera↗