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The description of emerging diseases unknown for the scientists before 90th has begun by the cooperative description of Astrakhan spotted fever by Irina Tarasevich and Didier Raoult. Molecular methods gave the possibility to distinguish its etiological agent from other rickettsiae and to prove that it differs from all other species, so this gave the background to describe the new disease. At the same time, this event promoted the collaboration between Russian and French groups of rickettsiologists. Collaborative studies of both groups in addition provoked the proposed idea of species criteria in rickettsioigy, that, in its turn, gave the way to revealing multiple novel rickettsiae and rickettsioses. I. Tarasevich created the stable cooperation with D. Raoult and this cooperation spread for all laboratories also. So, Oleg Mediannikov, Stan Shpynov, Anna Evstigneeva are always welcome in Marseille. Prolonged recently Cooperation Agreement between Gamaleya Institute and Universite de Mediterranee has brought already fine results and, hopefully, will bring yet the continuation of scientific and close friendly relationship.

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.Gamaleya Research Institute of Epidemiology and Microbiology. A total of 317 Ipersukatus imagoes were collected in the regions of the Urals, Western Siberia, Eastern Siberia, and Far East in the spring of 2001 and 2002. The authors detected R. tarasevichiae in 25.5 +/- 2.4% (87/317) of the examined I. persulcarus ticks, from 3.8% in the Novosibirsk Region (Western Siberia) to 56.8% in the Primorye Territory (the Far East). This is the first detection of the Rickettsiae in the ticks of the genus Ixodes in Russia. Conceivably, the spread of this Rickettsia species coincides with the area of I. persulcatus that inhabits the biotopes of southern taiga and mixed forests in Eurasia from the western frontier of Russia to the Far East. The nucleotide sequences of the fragments of gene 165 of pRNA and citrate synthctase of this species of Rickettsiae have been declared at the GenBank under numbers AF503168 and AF503167, respectively. Its most phylogenetically close species of Rickettsiae R. canadenss (69% homology in terms of the gene of citrate synthetase and 98% homology in terms of gene 165 of pRNA) which is responsible for cases of acute cerebral vasculitis in Northern America. This requires further studies of a possible role of R. tarasevichiae in the pattern of tick-borne infections recorded in the area of I. persulcatus.

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. sibirica, among them 3 isolates obtained from patients, 16 isolates obtained from Dermacentor ticks, 2 isolates from Haemaphysalis concinna and 2--from Ixodes persulcatus. The strain Primorye 32/84, isolated from D. silvarum ticks in the Far East and earlier identified as S. sibirica by the results of the PCR-RFLP analysis proved to be a genovariant Rickettsia spBJ-90, i.e. close to this species. Strain Karpunino 19/69, isolated in the Kurgan region, was identified as R. slovaca. The results obtained extended our notions of the spectrum of rickettsiae group TBSF in Russia as well as their vectors.

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. persulcatus ticks collected in the Tyumen, Omsk, and Novosibirsk Regions and the Altai Territory. Examining the Haemaphysalis concinna collected in the Primorye Territory revealed A. bovis DNA. The I. persulcatus ticks gathered in the Omsk Region were found to have "Ehrlichia-like "Schotti variant" DNA, Studying the ticks of the genera Dermatocentor and Hyalomma gathered in Russia and Kazakhstan failed to detect the representatives of the genera Anaplasma and Ehrlichia. The detection of A. phagocytophilia DNA in the I. persulcatus ticks in the Altai and Primorye territories and the serological verification of cases of human granulocytic anaplasmosis among patients with tick-borne infections in these territories lead to the conclusion that there are natural loci of this disease in West Siberia and the Far East of 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. At present at least 3 rickettsial species of the tick-borne spotted fever group were found in Ixodes ticks on the territory of Eastern Siberia: R. sibirica, known to be the etiological agent of tick-borne rickettsiosis, R. hulinii with proved pathogenicity for laboratory animals and R.DnS14 with no data available on its pathogenicity.

R. slovaca was first detected in the ticks D. marginatus gathered in the Stavropol Territory and the Voronezh Region (European Russia). The recently discovered rickettsial genotype DnS14 was first found in the ticks D. silvarum from Buryatia and D. niveus from the Karaganda Region (Central Kazakhstan). The rickettsial genotype RpA4 was most common in the ticks of the genus Dermacentor in Russia and Central Kazakhstan. An analysis of the spread of rickettsias of the STF group shows their close ecological relation to definite types of Ixodes. The rickettsias R. slovaca and RpA4 co-exist in the ticks D. marginatus and D. reticulatus (the western part of a Dermacentor area in Eurasia) and DnS14 and R. sibirica do in D. nuttalli and D. silvarum (the eastern part of the area). D. marginatus and D. reticulatus in the areas characterized by the most specific saturation of a Dermacentor area (the south of West Siberia) are carriers and reservoir of R. sibirica. The rickettsial genotype DnS28 may be now considered to be environmentally associated with one species of ticks--D. nuttalli. At least 6 genotypes of STF rickettsias--R. sibirica, R. astrahan fever (R. conorii), R. slovaca, RpA4, DnS14, DnS28--has been currently identified in Russia and Kazakhstan.

Ehrlichia infections are more and more common in the USA and Europe. The genetics and genome organization of Ehrlichia are little studied due to great difficulties in cultivating these bacteria. Pulse gel electrophoresis was first used to determine the sizes of a genome of 3 representatives of the genus Ehrlichia. The sizes of a genome was established for E. sennetsu (881 kb), for E. risticii (867 kb), E. chaffeensis (1,236 kb).