Bitencourth K, Amorim M, DE Oliveira S V, Caetano R L, Voloch C M, Gazêta G S
Laboratório de Referência Nacional em Vetores das Riquetsioses, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
Programa de Pós-Graduação em Biodiversidade e Saúde, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
Med Vet Entomol. 2017 Dec;31(4):427-437. doi: 10.1111/mve.12249. Epub 2017 Jul 28.
Amblyomma sculptum (Ixodida: Ixodidae) Berlese, 1888 is the most important tick vector in Brazil, transmitting the bioagent of the most severe form of spotted fever (SF) in part of the Cerrado (in the states of Minas Gerais and São Paulo). In another part of the Cerrado (Central-West region of Brazil), a milder form of SF has been recorded. However, neither the rickettsia nor the vector involved have been characterized. The aim of the current study was to analyse genetic variation and the presence of rickettsia in A. sculptum in Cerrado, from silent areas and with the milder form of SF. Samples were subjected to DNA extraction, amplification and sequencing of 12S rDNA, cytochrome oxidase subunit II and D-loop mitochondrial genes (for tick population analyses), and gltA, htrA, ompA and gene D (sca4) genes for rickettsia researches. Exclusive haplotypes with low frequencies, high haplotype diversity and low nucleotide diversity, star-shaped networks and significant results in neutrality tests indicate A. sculptum population expansions in some areas. Rickettsia amblyommatis, Candidatus Rickettsia andeanae and Rickettsia felis were detected. The A. sculptum diversity is not geographically, or biome delimited, pointing to a different potential in vector capacity, possibly associated with differing tick genetic profiles.
刻点血蜱（硬蜱目：硬蜱科），贝氏，1888年，是巴西最重要的蜱虫传播媒介，在塞拉多地区（米纳斯吉拉斯州和圣保罗州）的部分区域传播最严重形式的斑疹热（SF）生物病原体。在塞拉多的另一部分地区（巴西中西部地区），已记录到一种较温和形式的SF。然而，所涉及的立克次氏体和传播媒介均未得到鉴定。本研究的目的是分析塞拉多地区无病例和存在较温和形式SF地区的刻点血蜱的遗传变异及立克次氏体的存在情况。对样本进行DNA提取、12S rDNA、细胞色素氧化酶亚基II和D环线粒体基因（用于蜱虫种群分析）的扩增和测序，以及用于立克次氏体研究的gltA、htrA、ompA和基因D（sca4）基因的扩增和测序。低频的独特单倍型、高单倍型多样性和低核苷酸多样性、星形网络以及中性检验的显著结果表明刻点血蜱种群在某些地区有所扩张。检测到了安氏立克次氏体、安德立克次氏体（暂定种）和猫立克次氏体。刻点血蜱的多样性不受地理或生物群落的限制，这表明其在传播能力方面具有不同的潜力，可能与蜱虫不同的遗传特征有关。
