Occurrence of tick-borne pathogens in Lithuanian Rodent communities

Abstract

Rodents represent an important group of mammalian hosts as considered reservoirs of tick-borne pathogens. However, there still is a lack of knowledge on the occurrence and diversity of tick-borne pathogens of zoonotic importance in rodents from Baltic countries. This study aimed to investigate the prevalence and diversity of tick-borne bacterial pathogens Borrelia spp., Rickettsia spp. and protozoan Babesia parasite in rodent communities. Small rodents representing eight species - Apodemus flavicollis, A. agrarius, Mus musculus, Micromys minutus, Myodes glareolus, Microtus oeconomus, M. agrestis and M. arvalis were captured with live-traps in twelve different locations of Lithuania during 2013–2016. DNR was extracted from the spleen and urine bladder samples of small rodents. Real-time PCR and nested PCR were used to amplify different genome regions of Borrelia (ospA and 16S-23S ITS), Rickettsia (gltA and17kDa) and Babesia (18S rRNA) with subsequent sequence analysis. The overall prevalence of Borrelia spp. in rodent was 25%, Rickettsia spp. - 34.5 % and Babesia spp. – 6 %. Borrelia spp. were detected in six rodent species, M. arvalis, M. agrestis, M. glareolus, M.oeconomus, A. flavicollis, A. agrarius, Rickettsia spp. were detected in three species, A. flavicolis, M. minutus, and M. glareolus, and Babesia spp. – in A. flavicolis, M. minutus, M. glareolus, M.agrestis and M.oeconomus. All three pathogens were detected in A. flavicollis and M. glareolus. Sequence analysis of DNA from positive samples indicated the presence of two Borrelia species Borrelia afzelii and Borrelia miyamotoi, Rickettsia helvetica and Babesia microti. Coinfection with B. afzelii and B. microti was detected in M.oeconomus.