Molecular evidence of Rickettsia spp. in ixodid ticks and rodents in suburban, natural and rural habitats in Slovakia.
BACKGROUND
Natural foci of tick-borne spotted fever group (SFG) rickettsiae of public health concern have been found in Slovakia, but the role of rodents in their circulation is unclear. Ticks (Ixodes ricinus, Ixodes trianguliceps, Dermacentor marginatus, Dermacentor reticulatus, Haemaphysalis concinna and Haemaphysalis inermis) and tissues of rodents (Apodemus flavicollis, Apodemus sylvaticus, Myodes glareolus, Microtus arvalis, Microtus subterraneus and Micromys minutus) were examined for the presence of SFG rickettsiae and Coxiella burnetii by molecular methods. Suburban, natural and rural habitats were monitored to acquire information on the role of ticks and rodents in the agents' maintenance in various habitat types of Slovakia.


RESULTS
The overall prevalence of rickettsial infection in questing I. ricinus and D. marginatus was 6.6% and 21.4%, respectively. Rickettsia helvetica, R. monacensis and non-identified rickettsial species were detected in I. ricinus, whereas R. slovaca and R. raoultii were identified in D. marginatus. Rickettsia spp.-infected I. ricinus occurred during the whole tick questing period. Rickettsia helvetica dominated (80.5%) followed by R. monacensis (6.5%). The species were present in all studied habitats. Rickettsia slovaca (66.7%) and R. raoultii (33.3%) were identified in D. marginatus from the rural habitat. Apodemus flavicollis was the most infested rodent species with I. ricinus, but My. glareolus carried the highest proportion of Rickettsia-positive I. ricinus larvae. Only 0.5% of rodents (A. flavicollis) and 5.2% of engorged I. ricinus removed from My. glareolus, A. flavicollis and M. arvalis were R. helvetica- and R. monacensis-positive. Coxiella burnetii was not detected in any of the tested samples. We hypothesize that rodents could play a role as carriers of infected ticks and contribute to the maintenance of rickettsial pathogens in natural foci.


CONCLUSIONS
Long-term presence of SFG Rickettsia spp. was confirmed in questing ticks from different habitat types of Slovakia. The results suggest a human risk for infection with the pathogenic R. helvetica, R. monacensis, R. slovaca and R. raoultii.
Institute of Virology, Biomedical Research Center, Slovak Academy of Sciences, Dúbravská cesta 9, 845 05, Bratislava, Slovakia.
Lenka
L
Minichová
Institute of Zoology, Slovak Academy of Sciences, Dúbravská cesta 9, 845 06, Bratislava, Slovakia.
Zuzana
Z
Hamšíková
Institute of Zoology, Slovak Academy of Sciences, Dúbravská cesta 9, 845 06, Bratislava, Slovakia.
Lenka
L
Mahríková
Institute of Zoology, Slovak Academy of Sciences, Dúbravská cesta 9, 845 06, Bratislava, Slovakia.
Mirko
M
Slovák
Institute of Virology, Biomedical Research Center, Slovak Academy of Sciences, Dúbravská cesta 9, 845 05, Bratislava, Slovakia.
Elena
E
Kocianová
Institute of Zoology, Slovak Academy of Sciences, Dúbravská cesta 9, 845 06, Bratislava, Slovakia.
Mária
M
Kazimírová
Institute of Virology, Biomedical Research Center, Slovak Academy of Sciences, Dúbravská cesta 9, 845 05, Bratislava, Slovakia.
Ľudovít
Ľ
Škultéty
Institute of Virology, Biomedical Research Center, Slovak Academy of Sciences, Dúbravská cesta 9, 845 05, Bratislava, Slovakia.
Katarína
K
Štefanidesová
Institute of Virology, Biomedical Research Center, Slovak Academy of Sciences, Dúbravská cesta 9, 845 05, Bratislava, Slovakia. eva.spitalska@savba.sk.
Eva
E
Špitalská
D000818:Animals; D016997:Coxiella burnetii / Q000235:genetics / Q000302:isolation & purification; D017753:Ecosystem; D006801:Humans; D026863:Ixodidae / Q000382:microbiology*; D015995:Prevalence; D012281:Rickettsia / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D012282:Rickettsia Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D012377:Rodentia / Q000382:microbiology*; D012424:Rural Population; D017422:Sequence Analysis, DNA; D018154:Slovakia / Q000453:epidemiology; D013383:Suburban Population
Coxiella burnetii; Rickettsia spp.; Rodents; Slovakia; Ticks