Francisella tularensis prevalence and load in Dermacentor reticulatus ticks in an endemic area in Central Europe

0473982 - ÚBO 2018 RIV GB eng J - Článek v odborném periodiku
Hubálek, Zdeněk - Rudolf, Ivo
Francisella tularensis prevalence and load in Dermacentor reticulatus ticks in an endemic area in Central Europe.
Medical and Veterinary Entomology. Roč. 31, č. 2 (2017), s. 234-239. ISSN 0269-283X. E-ISSN 1365-2915
Institucionální podpora: RVO:68081766
Klíčová slova: Ixodid ticks * pathogen load * Tularaemia
Obor OECD: Epidemiology
Impakt faktor: 1.688, rok: 2017

A total of 7778 host-seeking adult Dermacentor reticulatus (Ixodida: Ixodidae) ticks were examined for the prevalence of Francisella tularensis holarctica (Thiotrichales: Francisellaceae) in a natural focus of tularaemia in the floodplain forest-meadow ecosystem along the lower reaches of the Dyje (Thaya) river in South Moravia (Czech Republic) between 1995 and 2013. Ticks were pooled (10 specimens per pool) and their homogenates inoculated subcutaneously in 4-week-old specific pathogen-free mice. Dead mice were sectioned, their spleens cultivated on thioglycollate-glucose-blood agar and impression smears from the spleen, liver and heart blood were Giemsa-stained. Sixty-four pools were positive for F. tularensis: the overall minimum infection rate (MIR) was 0.82%. Overall MIRs for the 4714 female and 3064 male D. reticulatus examined were 0.89 and 0.72%, respectively, MIRs fluctuated across years between 0.0 and 2.43%. The estimated bacterial load in infected ticks varied from 0.84 to 5.34 log10 infectious F.tularensis cells per tick (i.e. from about seven to 220000 cells). Ticks with low loads were more prevalent, more than 1000 infectious cells were detected in 24 ticks (0.3% of all ticks and 37.5% of infected ticks). Monitoring of D. reticulatus for the presence and cell numbers of F. tularensis may be a valuable tool in the surveillance of tularaemia.
Trvalý link: http://hdl.handle.net/11104/0271077