Philip R N, Casper E A
Am J Trop Med Hyg. 1981 Jan;30(1):230-8. doi: 10.4269/ajtmh.1981.30.230.
Adult Dermacentor andersoni ticks were collected by flagging vegetation in 18 canyons bordering the Bitterroot Valley, Montana, an area where nearly 400 cases of Rocky Mountain spotted fever (RMSF) have occurred since 1900. Three hundred and nine (8.3%) of the 3,705 ticks collected contained hemocyte-associated rickettsia-like organisms of three morphologic types, coccobacillary, fine bacillary, and coarse bacillary (long forms). Only the coccobacillary and fine bacillary organisms stained with fluorescein-conjugated antibody specific for the spotted fever group. One hundred and six isolates of spotted fever-group rickettsiae obtained by inoculation of Vero cells with suspensions of hemolymph test-positive ticks were serologically typed by microimmunofluorescence. Four sharply distinct serotypes were obtained, including Rickettsia rickettsii (10 strains), R. montana (8 strains), R. rhipicephali (47 strains), and a hitherto undescribed serotype referred to as 369-C (41 strains). All but two isolates were obtained from west-side canyons where virtually all cases of RMSF had been acquired. The four serotypes were widely distributed on the west side as evidenced by their presence in 5-11 of the 13 collecting sites. Each serotype induced distinctive plaques and cytopathogenicity in Vero cell culture.
通过在蒙大拿州比特鲁特山谷附近的18条峡谷中用布旗法采集植被上的成年安氏革蜱，自1900年以来，该地区已发生近400例落基山斑疹热（RMSF）。在采集的3705只蜱中，有309只（8.3%）含有三种形态类型的血细胞相关立克次氏体样生物，即球杆菌、细杆菌和粗杆菌（长形）。只有球杆菌和细杆菌生物体能用针对斑疹热群的荧光素结合抗体染色。通过用血淋巴检测呈阳性的蜱的悬液接种Vero细胞获得106株斑疹热群立克次氏体分离株，并用微量免疫荧光法进行血清学分型。获得了四种截然不同的血清型，包括立氏立克次氏体（10株）、蒙大拿立克次氏体（8株）、头状立克次氏体（4株）和一种迄今未描述的血清型，称为369-C（41株）。除两株分离株外，所有分离株均来自西侧峡谷，几乎所有RMSF病例都是在那里感染的。这四种血清型在西侧广泛分布，在13个采集地点中的5 - 11个地点都有发现。每种血清型在Vero细胞培养中诱导出独特的蚀斑和细胞致病性。
