Trudy Instituta imeni Pastera最新文献

Cluster sample technique has become a standard methodology for evaluation of immunization coverage and assessment of morbidity and mortality due to vaccine preventable and diarrhoeal diseases. The method is based on obtaining data in 30 randomly selected clusters and considered a statistically justified and economical alternative to the simple random sample approach. Cluster sample technique seems a relevant methodology for seroepidemiological studies and other surveys conducted as a part of surveillance of Rickettsial diseases.

Ixodid ticks are an important link in the ecology of rickettsiae. Some tick species became specific vectors as well as reservoirs of certain species of rickettsiae ensuring their long lasting maintenance via interstadial and transovarial transmission often over generations in nature. To now many significant questions on relationship between ticks and rickettsiae became clear, however, most of them still remain to be elucidated. The open question, for instance, involves the data on the differences in sensitivity of various tick species to a certain species of rickettsiae what has its significance concerning the transmission of an agent to a host. Intracoelomal injection of a tick with rickettsiae does not solve its role as a vector in nature, because the main natural barrier of tick organism against pathogens, i.e. alimentary tract with its specific biochemical properties, has been avoided. To specify a tick as a vector of rickettsiae, data on their maintenance in various developmental stages of the arthropod as well as transmission to a host through feeding the blood are desirable. More attention should be focused to investigation on antibacterial (antirickettsial) effect of lysosyme, interferon and cellular elements in arthropods. Certainly mixed infections in ticks and namely their interactions, as well as the significance of rickettsia-like organisms in these arthropods, require also further investigations. Sufficient conclusive evidence concerning the effect of vector's organism on the biological properties of rickettsiae or in reverse, are almost unavailable. Investigations on above problems require the involvement of the modernest methods of immunology, immunochemistry, biochemistry and morphology.

Coxiella burnetii has been investigated in different egg passages (EP-17, 163). Coxiella in EP 163 was completely eliminated from the suspension during the purification but not that in EP 17. It means that the coxiella of the two EP with a seroreaction of phase II are different, and phase II positivity of EP 17 can't be the result of presence of two populations in the suspension or of one mutation during the multiplication in yolk sacs but of a change on the surface of C. burnetii.

The represented materials characterise Q-fever situation in Voronezs region basing on data of long term observations. Three outbreaks and regularity of epidemiological process of this infection are described.

The author gives a review of occurrence of rickettsiae (Coxiella burnetii, R. slovaca, R. sibirica, R. prowazekii, R. mooseri, R. akari) in gamasid mites, investigated in laboratory or in nature. The results of our experiments and from literature also are summarized in tables. The experimental infection with C. burnetii was investigated by natural route of infection in the following species of mites: Haemogamasus nidi, H. hirsutus, Androlaelaps casalis. We found C. burnetii in smears, stained with Gimenez and IMF, with whole bodies as well as in their excrements. The white mice injected with the suspension from these mites gave the positive serological response.

Phospholipids are a part of the outside membrane of Coxiella burnetii (or other gram negative bacteria). It is possible to extract them with a mixture of chloroform-methanol (CM). For extraction of phospholipids from C. burnetii it is important to take account of temperature, proportion of CM, and reaction time. The best results are obtained at CM 2:1, at boiling point of this mixture and reaction time of 2 hours. Longer reaction time does not influence the reaction, the additional amounts of phospholipids can be extracted only with fresh solvent mixture.

It is proved that the challenging of the extract isolated from Coxiella (as a result of treatment with the mixture of chloroform and methanol) to animals doesn't provoke the appearance of antibodies to these microorganisms. It also doesn't cause the sensibilization of lymphocytes to Coxiella, but the extract can interact specifically with a serum containing antibodies to Coxiella. It permits to characterise the tested extract of Coxiella as a hapten with properties of adjuvant because it stimulates antibody-appearance.