Department of Entomology and Plath Pathology, North Carolina State University, Raleigh, NC 27695, USA.
Comparative Medicine Institute, North Carolina State University, Raleigh, NC 27695USA.
J Med Entomol. 2022 Jul 13;59(4):1382-1393. doi: 10.1093/jme/tjac033.
Host feeding patterns and the prevalence of infection with Rickettsia parkeri were determined for the primary vector, Amblyomma maculatum Koch as well as sympatric tick species A. americanum (Linnaeus) and Dermacentor variabilis (Say) collected from a reconstructed prairie in the Piedmont region of North Carolina during 2011 and 2012. The occurrence of R. parkeri among A. maculatum adults and nymphs was 36.9% (45/122) and 33.3% (2/6), respectively. Rickettsia parkeri was detected in a single male A. americanum 2.3% (1/43). A PCR-reverse line blot hybridization assay of a 12S rDNA fragment amplified from remnant larval and nymphal bloodmeals of host-seeking ticks was used to identify bloodmeal hosts. Of the tick samples tested, bloodmeal host identification was successful for 29.3% (12/41) of adult A. americanum and 39.2% (20/51) of adult D. variabilis. For A. maculatum, bloodmeal host identification was successful for 50% (61/122) of adults collected from vegetation and 100% (4/4) of nymphs removed from cotton rats (Sigmodon hispidus Say and Ord). The cotton rat was the most common bloodmeal host with 59.0% (36/61) identified for adult A. maculatum. No statistically significant association was observed, however, between bloodmeal host and pathogen prevalence for any tick species. While the cotton rat was an important bloodmeal host for A. maculatum nymphs, this vertebrate did not appear to be the primary source of R. parkeri infection for A. maculatum.
研究人员于 2011 年至 2012 年在北卡罗来纳州皮埃蒙特地区的一个重建草原上，对主要传播媒介孤星花蜱（Amblyomma maculatum Koch）以及共生的美洲钝缘蜱（A. americanum （Linnaeus））和变色革蜱（Dermacentor variabilis （Say））进行了宿主取食模式和感染斑点热立克次体（Rickettsia parkeri）的流行情况调查。在采集到的 122 只孤星花蜱成蜱中，有 36.9%（45/122）和 33.3%（2/6）的孤星花蜱成蜱和若蜱感染了斑点热立克次体。在 43 只雄性美洲钝缘蜱中，有 1 只雄性美洲钝缘蜱检测到斑点热立克次体，感染率为 2.3%（1/43）。采用 12S rDNA 片段 PCR-反向线杂交检测技术对宿主觅食蜱残留的幼虫和若虫血餐进行分析，以鉴定血餐宿主。在所检测的蜱样本中，成功鉴定出 29.3%（12/41）的美洲钝缘蜱成蜱和 39.2%（20/51）的变色革蜱成蜱的血餐宿主。对于孤星花蜱，在从植被中采集到的 50%（61/122）成蜱和从棉鼠（Sigmodon hispidus Say 和 Ord）身上取下的 100%（4/4）若蜱中，成功鉴定出其血餐宿主。棉鼠是最常见的血餐宿主，有 59.0%（36/61）的孤星花蜱成蜱以棉鼠为食。然而，任何一种蜱种的血餐宿主与病原体流行率之间均未观察到显著相关性。虽然棉鼠是孤星花蜱若蜱的重要血餐宿主，但这种脊椎动物似乎并不是孤星花蜱感染斑点热立克次体的主要来源。
