Departamento de Patología Animal (Grupo INVESAGA), Facultad de Veterinaria, Universidade de Santiago de Compostela, Lugo, Spain.
Exopol, Zaragoza, Spain.
Parasit Vectors. 2017 Dec 20;10(1):615. doi: 10.1186/s13071-017-2574-x.
Ixodes ricinus, the predominant tick species in Europe, can transmit the causative agents of important human diseases such as Lyme borreliosis (LB), caused by Borrelia spirochetes. In northern Spain, LB is considered endemic; recently, a significant increase of the annual incidence of LB was reported in the northwestern (NW) region.
In order to provide information on the prevalence of Borrelia spp., pooled and individually free-living I. ricinus from NW Spain were molecularly analyzed. Positive samples were characterized at the fla and Glpq genes and the rrfA-rrlB intergenic spacer region to identify Borrelia species/genospecies.
Borrelia burgdorferi (sensu lato) (s.l.) individual prevalence and MIR were significantly higher in adult females (32.3 and 16%) than in nymphs (18.8 and 6.2%) and adult males (15.6 and 8.4%). Five Borrelia genospecies belonging to the B. burgdorferi (s.l.) group were identified: B. garinii was predominant, followed by B. valaisiana, B. lusitaniae, B. afzelii and B. burgdorferi (sensu stricto) (s.s.). One species belonging to the tick-borne relapsing fever group (B. miyamotoi) was also found, showing low individual prevalence (1%), positive pool (0.7%) and MIR (0.1%) values. To our knowledge, this is the first citation of B. miyamotoi in free-living ticks from Spain.
The significant prevalences of B. burgdorferi (s.l.) genospecies detected in questing ticks from NW Spain are similar to those detected in northern and central European countries and higher to those previously found in Spain. These results together with the high incidence of LB in humans and the high seroprevalence of B. burgdorferi (s.l.) in roe deer shown in other studies reveal that the northwest area is one of the most risky regions for acquiring LB in Spain.
欧洲主要的蜱种——蓖子硬蜱（Ixodes ricinus）可传播伯氏疏螺旋体等病原体，这些病原体可导致莱姆病（Lyme borreliosis，LB）等重要人类疾病。在西班牙北部，LB 被认为是地方性疾病；最近，有报道称西北部（NW）地区 LB 的年发病率显著增加。
为了提供有关 Borrelia spp. 流行情况的信息，对来自西班牙西北部的聚集体和单独的自由生活的蓖子硬蜱进行了分子分析。对阳性样本进行 fla 和 Glpq 基因以及 rrfA-rrlB 基因间隔区的特征分析，以鉴定 Borrelia 种/基因型。
在成年雌性（32.3%和 16%）中，伯氏疏螺旋体（s.l.）个体流行率和 MIR 显著高于若虫（18.8%和 6.2%）和成年雄性（15.6%和 8.4%）。鉴定出 5 种属于伯氏疏螺旋体（s.l.）组的 Borrelia 基因型：B. garinii 占主导地位，其次是 B. valaisiana、B. lusitaniae、B. afzelii 和 B. burgdorferi（sensu stricto）（s.s.）。还发现了一种属于蜱传回归热群的物种（B. miyamotoi），其个体流行率（1%）、阳性池（0.7%）和 MIR（0.1%）均较低。据我们所知，这是首次在西班牙自由生活的蜱中发现 B. miyamotoi。
在西班牙西北部采集的游离蜱中检测到的伯氏疏螺旋体（s.l.）基因型的显著流行率与在北欧和中欧国家检测到的流行率相似，高于西班牙以前的流行率。这些结果以及在人类中 LB 的高发病率和其他研究中在狍子中检测到的伯氏疏螺旋体（s.l.）的高血清流行率表明，该西北部地区是西班牙获得 LB 风险最高的地区之一。
