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.

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 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.

"Candidatus Rickettsia tarasevichiae" in Ixodes persulcatus ticks collected in Russia.

We collected 209 Ixodes persulcatus ticks in various regions of Russia, including the southern Urals and western and eastern Siberia. Using PCR amplification and sequencing of the citrate synthase-encoding gene (gltA), we detected a new rickettsial genotype, which we named "Candidatus Rickettsia tarasevichiae." This bacterium was found in 9.

Bartonella henselae in Ixodes ricinus ticks (Acari: Ixodida) removed from humans, Belluno province, Italy.

The potential role of ticks as vectors of Bartonella species has recently been suggested. In this study, we investigated the presence of Bartonella species in 271 ticks removed from humans in Belluno Province, Italy. By using primers derived from the 60-kDa heat shock protein gene sequences, Bartonella DNA was amplified and sequenced from four Ixodes ricinus ticks (1.

First molecular evidence of new Bartonella spp. in fleas and a tick from Peru.

Fleas, lice, and ticks collected in Peru in a suburban area of Cusco in November 1998 were tested by polymerase chain reaction for the presence of Bartonella DNA using primers amplifying a fragment of the intergenic spacer region (ITS) gene. Three new Bartonella genotypes were detected in Pulex fleas self-collected from the beds and clothes of schoolchildren and adults. A fourth new genotype was also detected from a tick found on a sheep in the same area.