The enzootic life-cycle of Borrelia burgdorferi (sensu lato) and tick-borne rickettsiae: an epidemiological study on wild-living small mammals and their ticks from Saxony, Germany

Abstract

Background Borrelia burgdorferi (sensu lato) and rickettsiae of the spotted fever group are zoonotic tick-borne pathogens. While small mammals are confirmed reservoirs for certain Borrelia spp., little is known about the reservoirs for tick-borne rickettsiae. Between 2012 and 2014, ticks were collected from the vegetation and small mammals which were trapped in Saxony, Germany. DNA extracted from ticks and the small mammals’ skin was analyzed for the presence of Rickettsia spp. and B. burgdorferi (s.l.) by qPCR targeting the gltA and p41 genes, respectively. Partial sequencing of the rickettsial ompB gene and an MLST of B. burgdorferi (s.l.) were conducted for species determination.ResultsIn total, 673 small mammals belonging to eight species (Apodemus agrarius, n = 7; A. flavicollis, n = 214; Microtus arvalis, n = 8; Microtus agrestis, n = 1; Mustela nivalis, n = 2; Myodes glareolus, n = 435; Sorex araneus, n = 5; and Talpa europaea, n = 1) were collected and examined. In total, 916 questing ticks belonging to three species (Ixodes ricinus, n = 741; Dermacentor reticulatus, n = 174; and I. trianguliceps, n = 1) were collected. Of these, 474 ticks were further investigated. The prevalence for Rickettsia spp. and B. burgdorferi (s.l.) in the investigated small mammals was 25.3 and 31.2%, respectively. The chance of encountering Rickettsia spp. in M. glareolus was seven times higher for specimens infested with D. reticulatus than for those which were free of D. reticulatus (OR: 7.0; 95% CI: 3.3–14.7; P < 0.001). In total, 11.4% of questing I. ricinus and 70.5% of D. reticulatus were positive for Rickettsia spp. DNA of B. burgdorferi (s.l.) was detected only in I. ricinus (5.5%). Sequence analysis revealed 9 R. helvetica, 5 R. raoultii, and 1 R. felis obtained from 15 small mammal samples.ConclusionSmall mammals may serve as reservoirs for Rickettsia spp. and B. burgdorferi (s.l.). While the prevalence for Rickettsia spp. in M. glareolus is most likely depending on the abundance of attached D. reticulatus, the prevalence for B. burgdorferi (s.l.) in small mammals is independent of tick abundance. Dermacentor reticulatus may be the main vector of certain Rickettsia spp. but not for Borrelia spp.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-017-2053-4) contains supplementary material, which is available to authorized users.

Borrelia miyamotoi and Borrelia burgdorferi (sensu lato) identification and survey of tick-borne encephalitis virus in ticks from north-eastern Germany

“…Detection of B. burgdorferi (s.l.) in rodent populations from Germany with infection rates up to 49.1% confirmed the role of these small mammals as reservoir hosts [40,42]. The collection sites for ticks in the current study are extensive forest areas that could contain high abundance of voles or other rodents acting as infected reservoir hosts for the local tick population.…”

“…The overall prevalence of B. burgdorferi (s.l.) is lower compared to the infection rates registered in other studies from Germany [15,16,[40][41][42]. However, a previous study reported similar infection rates in I. ricinus ticks (16.8% of females, 12.9% of males and 5.7% of nymphs) collected in 2003 from woodlands in Mecklenburg-Western Pomerania [43], potentially indicating a constant circulation of B. burgdorferi (s.l.)…”

First detection of Rickettsia helvetica in small mammals in Lithuania

“…In Europe, six rickettsial pathogens— R. helvetica, R. raoultii, R. slovaca, R. conorii and R. felis —have been detected in rodents using molecular methods: R. helvetica in A. flavicollis, Apodemus sylvaticus, Apodemus agrarius, M. glareolus and Mus musculus [8] , R. raoultii in A. flavicollis and M. glareolus [14] , [15] , R. slovaca in Apodemus spp. [16] , R. conorii in A. sylvaticus and M. glareolus [1] and R. felis in A. flavicollis [15] . S. araneus has been found (based on serologic investigation) to be susceptible to R. helvetica infection [17] .…”

The diversity of tick-borne bacteria and parasites in ticks collected from the Strandja Nature Park in south-eastern Bulgaria

“…l .) by qPCR (C t < 33) were further examined by single-locus sequence typing targeting the recG gene (722 bp) [ 20 , 21 ]. Conventional PCRs were carried out in the Eppendorf MasterCycler Gradient Thermal Cycler (Eppendorf AG, Hamburg, Germany) and the products were visualized by gel-electrophoresis on 1.5% agarose gel stained with Midori Green (NIPPON, Genetics, Düren, Germany).…”