[Significance of red deer (Cervus elaphus) in the ecology of Borrelia burgdorferi sensu lato].

BACKGROUND: Red deer (Cervus elaphus) is one of the most important host of the adult tick (Ixodes ricinus) which is the basic vector of the Lyme disease causative agent--Borrelia burgdorferi sensu lato in Europe. The aim of the present study was to establish the role of red deer in the transmission of B. burgdorferi s.1. Material and methods. Tissues from 74 red deers were evaluated and the presence of B. burgdorferi s.1 DNA was identified using nested PCR technique based on fla gene. The identification of species belonging to B. burgdorferi s.1 complex was performed after restriction digestion of nested PCR product with Ddel enzyme and sequencing of nested PCR product. The study included also 55 isolates of I. ricinus females removed from red deer and 466 ticks (73 adult and 393 nymphs) collected from the vegetation in the area where the red deer lives.
RESULTS: There were no DNA of B. burgdorferi s.1 complex in the red deer tissues and in ticks removed from deer, however in one tick removed from deer the DNA of other Borrelia species--B. miyamotoi was identified. In ticks collected from vegetation 3 species belonging to B. burgdorferi s.1. complex were identified: B. garinii (3.2% ticks studied), B. afzelii (6.9%) and B. valaisiana (3.6%), however DNA of B. miyamotoi was absent. These results confirm inability of survival of B. burgdorferi s.1. species in tick I. ricinus feeding on red deer blood. However there is a possibility of survival of B. miyamotoi in presence of deer blood at least in ticks feeding on red deer. The main role of red deer in keeping the constant infection level of B. burgdorferi s.1. in the whole population of I. ricinus ticks does not concern B. miyamotoi.