Lyme borreliosis spirochetes in questing ticks from mainland Portugal
Lyme borreliosis spirochetes in questing ticks from mainland Portugal
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DOI：
10.1016/s1433-1128(04)80016-0
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发表时间：
2004-04-01
影响因子：
4.1
通讯作者：
Collares-Pereira, M
中科院分区：
文献类型：
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作者：
Baptista, S;Quaresma, A;Collares-Pereira, M
在葡萄牙，已经显示出蓖麻硬蜱含有属于广义伯氏疏螺旋体复合体的几种螺旋体的DNA，在生态区之间的遗传多样性存在重大差异。自1999年以来，已经获得了一些分离株，证实了这些蜱中的致病菌株的循环。蓖麻硬蜱被认为是一个广泛分布的物种，然而，在葡萄牙，它只在少数栖息地被发现。在这里，我们提出了初步的结果，从一个全国性的调查，探索我。蓖麻（n= 4，001）和其他硬蜱科（n = 1，534）在葡萄牙，开始于2001年。采样点（迄今为止为41个）是利用地理信息系统根据植被类型、可达性和人类病例的流行程度选择的。蜱类丰度和B类感染的时空分布。在选定地区测定蜱中的广义伯氏螺旋体。检查蜱是否存在B。4，001株中有719株感染了广义伯氏螺旋体。结果表明，蜱属中以扇头蜱属（Rhipicephalus，53%）、革蜱属（Dermacentor，34%）、革蜱属（I.蓖麻和璃眼蜱各占7%。马夫拉和格兰多拉场址，进行了更深入的研究，是I。蓖麻。然而，在这两个地点的疏螺旋体感染的患病率和循环螺旋体的遗传多样性观察到明显的差异。所有I.蓖麻分离物显示5个B。garinii，8 B. lusitaniae和1 B. valaisiana菌株，这是第一次在这些地区获得沿着相当大比例的蜱来源的PCR扩增子。两种硬蜱除I.格兰多拉的蓖麻也为B型。lusitaniae阳性，因此似乎参与了疏螺旋体的传播周期。在马夫拉的季节动态L蓖麻是双峰，更明显的是，在成年人比。目前的研究结果表明，B。在葡萄牙不同地理区域的当地蜱虫种群中，广义伯氏疏螺旋体的性质存在差异，葡萄牙某些地区获得莱姆病的风险高于先前的假设。
in Portugal, Ixodes ricinus ticks have been shown to contain DNA of several spirochetes belonging to the Borrelia burgdorferi sensu lato complex, with major differences in the genetic diversity between ecozones. Some isolates have been obtained since 1999, confirming the circulation of pathogenic strains in these ticks. Ixodes ricinus is considered to be a widespread species, however, in Portugal it is found only in a few habitats. Here we present preliminary results from a nationwide survey of questing I. ricinus (n= 4,001) and other Ixodidae (n = 1,534) in Portugal, initiated in 2001. The sampling points (so far 41) were selected using a Geographic Information System, according to the type of vegetation, accessibility and prevalence of human cases. The spatial and temporal of tick abundance and the infection of B. burgdorferi sensu lato in ticks were determined in selected areas. Ticks were examined for the presence of B. burgdorferi sensu lato by culturing (719 out of 4,001 I. ricinus), and direct PCR amplification of the 5S-23S intergenic spacer region (1,870 out of 5,535) followed by RFLP analysis, the reverse line blot assay and nucleotide sequencing of PCR amplicons.The most abundant tick genus was Rhipicephalus (53%), followed by Dermacentor (34%), I. ricinus and Hyalomma (7%, each). The Mafra and Grandola sites., where a more intensive study was carried out, were excellent habitats for I. ricinus. However, a clear difference of the prevalence of Borrelia infection and the genetic diversity of circulating spirochetes was observed in these two sites. Genotyping of all I. ricinus isolates revealed 5 B. garinii, 8 B. lusitaniae and 1 B. valaisiana strains, which were obtained for the first time in these regions along with a considerable percentage of tick-derived PCR amplicons. Two hard-tick species other than I. ricinus in Grandola were also B. lusitaniae positive, thus seeming to take part in the transmission cycle of Borrelia. The seasonal dynamics of L ricinus in Mafra was bimodal, more pronounced in nymphs than in adults. The present findings indicate that B. burgdorferi sensu lato agents are differentially maintained in nature in local tick populations in different geographic areas across Portugal and that the risk of acquiring Lyme borreliosis in certain areas of Portugal is higher than previously assumed.