Kelly Patrick, Lucas Helene, Beati Lorenza, Yowell Charles, Mahan Suman, Dame John
Ross University School of Veterinary Medicine, West Farm Road, Basseterre, St. Kitts and Nevis, West Indies.
J Parasitol. 2010 Dec;96(6):1086-8. doi: 10.1645/GE-2552.1. Epub 2010 Jul 29.
We used PCRs with omp A primers to determine if spotted fever group rickettsiae occurred in Amblyomma variegatum from 6 Caribbean islands. Positive amplicons were obtained from ticks from the U.S. Virgin Islands (9/18; 50%), Dominica (39/171; 30%), Montserrat (2/5; 40%), Nevis (17/34; 50%), St. Kitts (46/227; 20%), and St. Lucia (1/14; 7%). Sequences for a convenience sample of reaction products obtained from A. variegatum on St. Kitts (7), American Virgin Islands (4), Montserrat (2), and St. Lucia (1) were 100% homologous with that of Rickettsia africae , the agent of African tick-bite fever. To determine if transmission of R. africae occurred, we used Rickettsia rickettsii antigen in IFA tests and found positive titers (≥ 1/80) with sera from cattle, goats, and sheep from Dominica (24/95 [25%], 2/136 [2%], 0/58 [0%]), Nevis (12/45 [27%], 5/157 [3%], 0/90 [0%]), St. Kitts (2/43 [5%], 1/25 [4%), 1/35 [3%]), and St. Lucia (6/184 [3%] cattle), respectively. No seropositive animals were found in Grenada (0/4, 0/98/, 0/86), Montserrat (0/12, 0/26, 0/52), or Puerto Rico (0/80 cattle). Our study indicates that R. africae and African tick-bite fever are widespread in the Caribbean.
我们使用omp A引物进行聚合酶链反应（PCR），以确定来自6个加勒比岛屿的变异革蜱中是否存在斑点热群立克次体。从美属维尔京群岛（9/18；50%）、多米尼克（39/171；30%）、蒙特塞拉特（2/5；40%）、尼维斯（17/34；50%）、圣基茨（46/227；20%）和圣卢西亚（1/14；7%）的蜱中获得了阳性扩增子。从圣基茨（7只）、美属维尔京群岛（4只）、蒙特塞拉特（2只）和圣卢西亚（1只）的变异革蜱中获取的反应产物的便利样本序列与非洲蜱咬热病原体非洲立克次体的序列100%同源。为了确定非洲立克次体是否发生传播，我们在间接免疫荧光试验（IFA）中使用立氏立克次体抗原，发现来自多米尼克的牛、山羊和绵羊血清（24/95 [25%]、2/136 [2%]、0/58 [0%]）、尼维斯（12/45 [27%]、5/157 [3%]、0/90 [0%]）、圣基茨（2/43 [5%]、1/25 [4%]、1/35 [3%]）和圣卢西亚（6/184 [3%]牛）的阳性滴度（≥1/80）。在格林纳达（0/4、0/98、0/86）、蒙特塞拉特（0/12、0/26、0/52）或波多黎各（0/80头牛）未发现血清阳性动物。我们的研究表明，非洲立克次体和非洲蜱咬热在加勒比地区广泛存在。
