Abstract：
In Europe, Ixodes ricinus plays a major role as a vector of Borrelia burgdorferi sensu lato (s.l.) spirochaetes, the causative agents of Lyme borreliosis, among other pathogens. In unfed ticks, Borrelia spirochaetes experience prolonged nutrient restriction. However, only few studies exist with regard to Borrelia infections in unfed ticks of different physiological ages. Changing body dimensions of unfed ticks, due to the consumption of energy reserves, allow physiological age estimation. The present study investigated the relationship of morphometric age with Borrelia prevalence and spirochaete load in 1882 questing I. ricinus nymphs, collected at two different locations in northern Germany in 2020. In addition, Borrelia species composition was investigated by employing a reverse line blot (RLB) probe panel suitable for the detection of ten different B. burgdorferi s.l. species, as well as the relapsing-fever spirochaete B. miyamotoi. Overall, Borrelia prevalence was 25.8% (485/1882). Whilst there was no statistically significant difference in Borrelia prevalence between the different morphometric age groups, Borrelia infection intensity as determined by probe-based quantitative real-time PCR significantly declined with increasing morphometric age. Borrelia species differentiation by RLB was successful in 29.5% of positive ticks, and revealed B. afzelii as the dominating species (65.0% of the differentiated infections). Additionally, B. garinii, B. valaisiana, B. burgdorferi sensu stricto, B. spielmanii, and B. miyamotoi were detected.
摘要：
在欧洲,蓖麻Ixodes作为伯氏疏螺旋体（s.l.）螺旋体的载体起着重要作用，莱姆病的病原体，在其他病原体中。在未喂食的蜱中，螺旋体疏螺旋体经历长期的营养限制。然而,关于不同生理年龄的未喂食壁虱的疏螺旋体感染的研究很少。改变未喂食蜱的身体尺寸，由于能源储备的消耗，允许生理年龄估计。本研究调查了1882年蓖麻若虫的形态年龄与疏螺旋体患病率和螺旋体负荷的关系，2020年在德国北部的两个不同地点收集。此外,通过使用适用于检测十种不同的伯氏芽孢杆菌的反向线印迹（RLB）探针组来研究疏螺旋体属物种组成。以及复发性热病螺旋体B.miyamotoi。总的来说,疏螺旋体病患病率为25.8%(485/1882)。虽然不同形态年龄组之间的疏螺旋体病患病率没有统计学上的显着差异，通过基于探针的定量实时PCR确定的疏螺旋体感染强度随形态年龄的增加而显着下降。通过RLB的疏螺旋体物种分化在29.5％的阳性蜱中成功，并显示阿夫泽利芽孢杆菌为主要物种(分化感染的65.0%)。此外,B.Garinii,B.valaisiana,B.Burgdorferisensustricto，B.Spielmanii,和B.miyamotoi被检测到。
