Abstract
BackgroundIxodes ricinus is the most common tick species in Europe and the main vector for Borrelia burgdorferi (sensu lato) and tick-borne encephalitis virus (TBEV). It is involved also in the transmission of Borrelia miyamotoi, a relapsing fever spirochete that causes health disorders in humans. Little is known regarding the circulation of Borrelia species and the natural foci of TBEV in north-eastern Germany. The goal of this study was to investigate the infection rates of Borrelia spp. and of TBEV in I. ricinus ticks from north-eastern Germany.MethodsTicks were collected by flagging from 14 forest sites in Mecklenburg-Western Pomerania between April and October 2018. RNA and DNA extraction was performed from individual adult ticks and from pools of 2–10 nymphs. Real time reverse transcription PCR (RT-qPCR) targeted the 3′ non-coding region of TBEV, while DNA of Borrelia spp. was tested by nested PCR for the amplification of 16S-23S intergenic spacer. Multilocus sequence typing (MLST) was performed on B. miyamotoi isolates.ResultsIn total, 2407 ticks were collected (239 females, 232 males and 1936 nymphs). Female and male I. ricinus ticks had identical infection rates (both 12.1%) for Borrelia spp., while nymphal pools showed a minimum infection rate (MIR) of 3.3%. Sequencing revealed four Borrelia species: B. afzelii, B. garinii, B. valaisiana and B. miyamotoi. Borrelia afzelii had the highest prevalence in adult ticks (5.5%) and nymphs (MIR of 1.8%). Borrelia miyamotoi was identified in 3.0% of adults and registered the MIR of 0.8% in nymphs. Borrelia valaisiana was confirmed in 2.5% adult ticks and nymphs had the MIR of 0.7%, while B. garinii was present in 1.1% of adults and showed a MIR of 0.1% in nymphs. The MLST of B. miyamotoi isolates showed that they belong to sequence type 635. No tick sample was positive after RT-qPCR for TBEV RNA.ConclusionsThe prevalence of B. miyamotoi in I. ricinus ticks registered similar levels to other reports from Europe suggesting that this agent might be well established in the local tick population. The detection of B. burgdorferi (s.l.) indicates a constant circulation in tick populations from this region.
Highlights
Ixodes ricinus is the most common tick species in Europe and the main vector for Borrelia burgdorferi and tick-borne encephalitis virus (TBEV)
In total, 2407 ticks were collected from April to October 2018 in 14 sites from Mecklenburg-Western Pomerania (Fig. 1), all identified as I. ricinus, of nymphal and adult stage only
Borrelia afzelii sequences obtained in this study showed high similarity with isolate strains from Norway (GenBank: KY782011), Germany (GenBank: CP002933), Sweden (GenBank: FJ750344) and Ukraine
Summary
Ixodes ricinus is the most common tick species in Europe and the main vector for Borrelia burgdorferi (sensu lato) and tick-borne encephalitis virus (TBEV). It is involved in the transmission of Borrelia miyamotoi, a relapsing fever spirochete that causes health disorders in humans. The most relevant pathogens for which I. ricinus is a competent vector are Borrelia burgdorferi (sensu lato), the agent responsible for Lyme disease and the tick-borne encephalitis virus (TBEV) [4, 5]. Spirochetes of the B. burgdorferi (s.l.) complex can cause Lyme borreliosis, the most frequent tick-borne disease of humans in the Northern Hemisphere [6]. Detection of B. burgdorferi (s.l.) in ticks from Germany was reported in several studies, prevalence rates ranging from 2% up to 36.2% in the southern part of the country [11,12,13,14,15,16,17,18,19]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
