Real-time PCR validation to estimate the number of rickettsias in the biological material under study.

Using the example of the clinical strain of R. sibirica «Bayevo 105/87», the possibility of quantitative determination of rickettsias in clinical samples from patients with Siberian tick-borne typhus by real-time polymerase chain reaction (PCR-RT) was evaluated. Cultivation was carried out in the yolk sacs of developing chicken embryos, from which a piece of the yolk sac or chorion was taken.

Avidity of IgG to Rickettsia prowazekii and the presence of specific IgM in blood sera for retrospective analysis of the 1998 epidemic typhus outbreak in Russia.

The authors applied a new methodological approach based not only on the study of IgM/IgG to Rickettsia prowazekii in sera, but also on the estimation of the avidity index of specific IgG. The data allowed the authors to draw new conclusions about the 1998 epidemic typhus outbreak in Russia.

[Retrospective serological diagnostics of spotted fever group rickettsioses in high risk areas of Rickettsia conorii subsp. Caspia infection.].

723 blood sera from 537 patients of Regional Infectious Clinical Hospital, Astrakhan were obtained during high activity period of Rhipicephalus ticks (May-September 2015) and retrospectively studied for IgG/IgM to antigen of spotted fever group (SFG) Rickettsia. IgG and/or IgM to Rickettsia conorii were detected in 145 sera from 130 patients, and antibodies to R. sibirica (group-specific) were detected in 143 sera from 145.

New approaches in the systematics of rickettsiae.

The development of a formal order analysis (FOA) allowed constructing a classification of 49 genomes of family representatives. Recently FOA has been extended with new tools-'Map of genes,' 'Matrix of similarity' and 'Locality-sensitive hashing'-for a more in-depth study of the structure of rickettsial genomes. The new classification confirmed and supplemented the previously constructed one by determining the position of str.

Comparison of genomes of strains using formal order analysis.

The  strain NL3262 was isolated during the Q fever outbreak in the Netherlands in 2007-2010. Formal-order analysis (FOA) was used to study the similarity of the genome (chromosome and plasmid) of this strain with the genomes from other strains. Chromosomes from ten strains and eight plasmids were studied with FOA tools such as 'Map of genes' and 'Matrix of similarity.

Rickettsiologist Pavel F. Zdrodovskii: larger than life, and not just for his famous book.

This article highlights the biography and scientific accomplishments of Pavel F. Zdrodovskii and his contributions to understanding the biology, pathogenesis, treatment, prevention and epidemiology of brucellosis, rickettsioses and many other infectious diseases.

[ON THE ROLE OF RICKETTSIA RAOULTII IN THE EPIDEMIOLOGY OF RICKETTSIOSES IN RUSSIA].

The paper analyzes data on the prevalence and possible epidemiological importance of Rickettsia raoultii. The possible risk of infection in the population was assessed from the results of a serological study of patients after tick suction and from those of molecular biological determination of contamination of removed carriers. The place of Rickettsia raoultii among other rickettsia causing rickettsioses of a tick-borne spotted fever group is assessed in Russia.

[BRILL-ZINSER DISEASE AS A CONSEQUENCE OF RICKETTSIA PROWAZEKII PERSISTENCE IN PREVIOUSLY ILL WHO HAVE HAD EPIDEMIC TYPHUS (EPIDEMIOLOGIC ASPECTS)].

Materials, that summarize data of original research and scientific literature on epidemiology and problems of persistence during epidemic typhus, whose causative agent (Rickettsia prowazekii) is reactivated in the organism of the previously ill and is manifested as Brill-Zinser disease, are presented. A retrospective analysis was carried out with the data obtained by Russian (All-Union) Centre for Rickettsioses during study of epidemiologic examination maps of 5705 typhus nidi and results of 19 463 blood sera analysis during study of immunologic structure of population in the territories of the former USSR for the period from 1970 to 1992. A decrease of epidemic typhus morbidity and an increase of the fraction of Brill-Zinser disease took place as a result of pediculosis corporis control.

Approach for classification and taxonomy within family Rickettsiaceae based on the Formal Order Analysis.

Genome sequences of 36 Rickettsia and Orientia were analyzed using Formal Order Analysis (FOA). This approach takes into account arrangement of nucleotides in each sequence. A numerical characteristic, the average distance (remoteness) - "g" was used to compare of genomes.

New evidence on tick-borne rickettsioses in the Altai region of Russia using primary lesions, serum and blood clots of molecular and serological study.

Tick-borne rickettsioses (TBRs) have similar clinical symptoms and can give serological cross-reaction. We firstly found that in the natural foci of North Asian tick typhus (NATT) in the Altai region of Russia, TBRs can be caused by two Rickettsia species: Rickettsia sibirica subsp. sibirica (causative agent of NATT) and Rickettsia heilongjiangensis.

Ixodes persulcatus, a major vector of Alphaproteobacteria in Russia.

Ixodes persulcatus Schulze, 1930 (I. persulcatus) is distributed from the western to the eastern borders of Russia where it is found in the taiga and in mixed forests of the European type. This tick is a known vector of viral (tick-borne encephalitis virus), spirochetal (Borrelia spp.

Detection of members of the genera Rickettsia, Anaplasma, and Ehrlichia in ticks collected in the Asiatic part of Russia.

A total of 395 adult ixodid ticks from three genera (Dermacentor, Haemaphysalis, and Ixodes) collected from the Urals to the Far East of Russia were tested by PCR and sequencing for the presence of spotted fever rickettsiae, anaplasmae, and ehrlichiae. Four, pathogens recognized in humans were detected in ticks: Rickettsia sibirica, R. heilongjiangensis, R.

Ecology and molecular epidemiology of tick-borne rickettsioses and anaplasmoses with natural foci in Russia and Kazakhstan.

During our more than 20 years of monitoring, we have used epidemiological, field, and experimental methods for characterization of natural foci of tick-borne rickettsioses in Russia. The main results were obtained through genetic methods (PCR sequence) at the Université de la Mediterranée (Marseille, France). We describe considerable heterogeneity of tick-borne alpha(1)-proteobacteria: 16 microorganisms the of the order Rickettsiales were detected in Russia and Kazakhstan.

Molecular identification of a collection of spotted Fever group rickettsiae obtained from patients and ticks from Russia.

Thirty-one rickettsial isolates from ticks or patients in North Asian tick typhus (NATT) foci from the Ural region to the Russian Far East were obtained at the Omsk Research Institute of Natural Foci Infections between 1954 and 2001. Using citrate synthase (gltA) and outermenbrane protein a (ompA) gene sequencing, we identified these isolates as Rickettsia sibirica sensu stricto (25 isolates), R. sibirica strain BJ-90 (2 isolates), R.

[Detection of a new species of Rickettsiae in the ticks of Ixodes persulcatus in Russia].

Genetic analyses (polymerase chain reaction and nucleotide sequence test) have been used to describe a new species of Rickettsiae in the ticks Ipersukarus in Russia. This species is named as Rzckettsia tarasevichiae after Academician of the Russian Academy of Medical Sciences Irma Vladimirovna Tarasevich, Head of the Laboratory of Rickettsial Ecology, N.F.

[Genetic identification of rickettsiae of the tick-borne spotted fever group, isolated in the foci of tick-borne rickettsiosis].

A total of 25 rickettsial cultures of the tick-borne spotted fever (TBSF) group from the collection of the Research Institute of Infections in Omsk, isolated from different sources in the territory of the Russian Federation (from the Urals to the Far East) during the period of 1954-2001) were studied by the methods of genetic analysis. The fragments of the gene coding the outer-membrane protein of 190 kD (ompA) and synthetase citrate (gltA) of the rickettsiae under the study were sequenced. 23 isolates were identified as R.

[New evidence for the detection of ehrlichia and anaplasma in ixodes ticks in Russia and Kazakhstan].

Polymerase chain reaction and sequence analysis were used to screen Ehrlichia and Anaplasma DNA in 900 specimens of Ixodes ticks of four genera (Dermacetor, Haemaphysalis, Ixodes, and Hyalomma) collected on 14 administrative territories of Russia and Kazakhstan. Anaplasma phagocytophilia DNA was detected and identified in Ixodes persulcatus ticks gathered in the Altai and Primorye Territories. Ehrlichia muris DNA was genotyped in the I.

[Detection of Rickettsia hulinii in ticks of the Haemaphysalis concinna species in Russia].

The presence of Rickettsia hulinii was detected in ticks of the Haemaphysalis concinna species in the Asiatic part of Russia. It was the first detection of these rickettsiae outside the territory of the Chinese People's Republic. This tick is spread over a broken area and may occur in different regions of Eurasia.

Detection of a rickettsia closely related to Rickettsia aeschlimannii, "Rickettsia heilongjiangensis," Rickettsia sp. strain RpA4, and Ehrlichia muris in ticks collected in Russia and Kazakhstan.

Using PCR, we screened 411 ticks from four genera collected in Russia and Kazakhstan for the presence of rickettsiae and ehrlichiae. In Russia, we detected "Rickettsia heilongjiangensis," Rickettsia sp. strain RpA4, and Ehrlichia muris.

[Genotyping of spotted tick fever rickettsiae, detected in Russia and Kazakhstan].

R. slovaca was first detected in the ticks D. marginatus gathered in the Stavropol Territory and the Voronezh Region (European Russia).