Global evolution and phylogeography of Brucella melitensis strains.

Background: Brucellosis is a bacterial zoonotic disease. Annually in the world more than 500,000 new cases of brucellosis in humans are registered. In this study, we propose an evolutionary model of the historical distribution of B.

[DETERMINATION OF PHYLOGENETIC RELATIONSHIP OF YERSINIA PESTIS STRAINS FROM NATURAL PLAGUE FOCI OF THE CAUCASUS BY MULTI-LO- CUS VNTR-ANALYSIS].

Aim: Determination of the degree of phylogenetic relationship of Yersinia pestis strains iso- lated from the territories of natural foci of plague from the Caucasus using VNTR-typing by 25 loci (MLVA25).

Materials And Methods: 26 strains of Y pestis from Russian natural foci of the Caucasus were used in the study. 25 loci of tandem repeats in Y pestis genome by Le Fleche scheme were used for execution of multi-locus VNTR-analysis.

[FEATURES OF MASS-SPECTROMETRIC PROTEIN PROFILES OF STRAINS OF BRUCELLOSIS CAUSATIVE AGENT DURING PREPARATION OF CULTURE ON VARIOUS NUTRIENT MEDIA].

Aim: Carry out comparative analysis using time-of-flight mass-spectrometry with matrix laser desorption/ionization (MALDI-TOF MS) of protein profiles of brucellosis causative agents (Brucella melitensis Rev-1 and Brucella abortus 19BA), cultivated in various nutrient media: Albimi agar, brucellagar and erythrit-agar.

Materials And Methods: Vaccine,strains: Brucella melitensis Rev-1 and Brucella abortus 19BA. Protein profiling in linear mode on Microflex "Bruker Daltonics" MALDI-TOF mass-spectrometer.

[The duration of preservation of plague pathogen strains with a different plasmid kit from a Central Caucasian high-altitude natural focus in the organism of citellophilus tesquorum fleas and the possibility of their transmission to laboratory animals].

Two plasmid variants of the main subspecies of the plague microbe circulate in a Central Caucasian high-altitude natural focus of plague. The strains of one plasmid variant fully correspond to the main subspecies of the plague pathogen in their characteristics. Those of the other are auxotrophic for proline, weakly virulent to one or both species of laboratory animals.

[Relations of the causative agents of plague and listeriosis during their simultaneous stay in the flea Citellophilus tesquorum at different environmental temperatures].

Experiments were carried out to determine the persistence of a plague microbe with varying praline labeling (isolated in the Central Caucasian mountain focus of plague in the fleas Citellophilus tesquorum of a mountain subspecies) in the contamination of the mixed culture of the plague microbe and Listeria. Inoculation of fleas with a suspension of a plague microbe and Listeriae demonstrates the manifest signs of antagonism between both species of microorganisms. This is evidenced by the reductions in the time of cultivation and in the number ofthese bacterial species in the experimental group fleas co-infected with Yersinia pestis and Listeria monocytogenes as compared with the control fleas (infected with monocultures of the causative agents of plague and listeriosis).

[Detection of plague microbe in the fleas by polymerase chain reaction by using magnetic immunosorbents].

The polymerase chain reaction (PCR) with and without pre-treatment of the samples of the fleas Citellophilus tesquorum with magnoimmunosorbents was used to detect the plague microbe in the samples containing 142, 168, 193 or more bacterial cells. PCR analysis reduced the time of tests of ectoparasites for plague to 6 hours. The use of a combination of PCR and magnoimmunosorbent simplified the most time-consuming and longest stage of isolation of plague microbial DNA from the suspensions of the fleas, which allows the time of a test to be reduced to 3 hours.

[Current state of epidemiologic surveillance of natural foci of plague of North Caucasus].

Information on the epizootic situation in plague in the natural foci of North Caucasus and on the influence of a number of anthropogenic and natural factors on this situation is presented. The data given in this work indicate that under the conditions of the anthropogenic transformation of landscapes the character of the epizootic manifestations of plague is changed and new factors, capable of aggravating epidemiological situation, appear. In addition, some other factors must be considered, such as the insufficient financing of reliable field surveys at present, the impossibility of making reliable epizootological studies due to causes of the social character (armed conflicts), thus making it impossible to evaluate, with a sufficient degree of reliability, the real epizootic state of a number of territories and, therefore, the risk of human infection.