1. Laboratory of Rickettsial Ecology; Gamaleya Research Institute of Epidemiology and Microbiology; Moscow 123098 Russia
2. Department of the Infectious Diseases; Far Eastern State Medical University; Khabarovsk 680000 Russia
3. Unité des Rickettsies, Faculté de Médecine, CNRS UMR 6020 27; Université de la Méditerranée; 13005 Marseille Cedex 05 France
4. Khabarovsk Plague Control Station of Ministry of Health of Russian Federation; Khabarovsk 680000 Russia