Abstract:
Myxobolus cerebralis (Bivalvulida: Myxobolidae), the aetiological agent of salmonid whirling disease, was detected in 2 river basins of North Carolina during 2015, which initiated the largest spatial-temporal monitoring project for the disease ever conducted within the south-eastern United States (focused mainly in eastern Tennessee and western North Carolina). A total of 2072 rainbow trout Oncorhynchus mykiss, 1,004 brown trout Salmo trutta and 468 brook trout Salvelinus fontinalis were screened from 113 localities within 7 river basins during June 2017 through October 2019. Infections were detected by pepsin-trypsin digest, microscopy and the species-specific nested polymerase chain reaction (PCR) in 19 localities across 6 river basins. Myxospore morphology was indistinguishable from the published literature. In 2019, five rainbow trout that symptomatic for whirling disease (sloping neurocranium and lordosis) were captured and processed for histopathology. Myxospores were detected in the calvarial cartilage of two deformed trout with associated erosion of the cartilage consistent with reported whirling disease lesions. This is the first report of M. cerebralis in Tennessee and the first histologically confirmed cases of whirling disease in southern Appalachian (south-eastern United States) rivers and streams and expands the distribution of M. cerebralis throughout western North Carolina and eastern Tennessee.
摘要:
大脑Myxobolus(Bivalida:Myxobolida),沙门氏菌漩涡病的病因,2015年在北卡罗来纳州的2个流域中检测到,该流域启动了美国东南部(主要集中在田纳西州东部和北卡罗来纳州西部)有史以来最大的疾病时空监测项目。总共2072条虹鳟鱼Oncorhynchusmykiss,在2017年6月至2019年10月期间,从7个流域内的113个地区筛选了1,004条棕鳟鱼Salmotrutta和468条溪鳟鱼Salvelinusfontinalis。通过胃蛋白酶-胰蛋白酶消化检测感染,在6个流域的19个地区进行了显微镜检查和物种特异性巢式聚合酶链反应(PCR)。粘孢子形态与已发表的文献没有区别。在2019年,捕获了五只具有旋转疾病(倾斜的神经颅骨和脊柱前凸)症状的虹鳟鱼,并进行了组织病理学处理。在两个变形鳟鱼的颅骨软骨中检测到粘孢子,并伴有软骨侵蚀,与报告的旋转疾病病变一致。这是田纳西州大脑分枝杆菌的第一份报告,也是阿巴拉契亚南部(美国东南部)河流和溪流中第一例经组织学证实的旋转疾病病例,并扩大了大脑分枝杆菌在北卡罗来纳州西部和田纳西州东部的分布。