Marquis Nicholas D, Bishop Theodore J, Record Nicholas R, Countway Peter D, Fernández Robledo José A
Bigelow Laboratory for Ocean Sciences, Boothbay, ME 04544, USA.
Department of Marine Sciences, Southern Maine Community College, South Portland, ME 04106, USA.
Pathogens. 2020 Mar 31;9(4):256. doi: 10.3390/pathogens9040256.
Eastern oyster (Crassostrea virginica) aquaculture is increasingly playing a significant role in the state of Maine's (USA) coastal economy. Here, we conducted a qPCR-based survey for Haplosporidium nelsoni, Perkinsus marinus, and Perkinsus chesapeaki in C. virginica (n = 1440) from six Maine sites during the summer-fall of 2016 and 2017. In the absence of reported die-offs, our results indicated the continued presence of the three protozoan parasites in the six sites. The highest H. nelsoni qPCR-prevalence corresponded to Jack's Point and Prentiss Island (x=40 and 48% respectively), both located in the Damariscotta River Estuary. Jack's Point, Prentiss Island, New Meadows River, and Weskeag River recorded the highest qPCR-prevalence for P. marinus (32-39%). While the P. marinus qPCR-prevalence differed slightly for the years 2016 and 2017, P. chesapeaki qPCR-prevalence in 2016 was markedly lower than 2017 (<20% at all sites versus >60% at all sites for each of the years, respectively). Mean qPCR-prevalence values for P. chesapeaki over the two-year study were ≥40% for samples from Jack's Point (49%), Prentiss Island (44%), and New Meadows River (40%). This study highlights that large and sustained surveys for parasitic diseases are fundamental for decision making toward the management of the shellfish aquaculture industry, especially for having a baseline in the case that die-offs occur.
东部牡蛎（美洲牡蛎）养殖在美国缅因州沿海经济中发挥着越来越重要的作用。在此，我们于2016年和2017年夏秋季节，对缅因州六个地点的1440只美洲牡蛎进行了基于定量聚合酶链反应（qPCR）的调查，以检测其中的尼尔森单孢子虫、马里努斯派琴虫和切萨皮克派琴虫。在没有报告出现死亡事件的情况下，我们的结果表明这三种原生动物寄生虫在这六个地点持续存在。尼尔森单孢子虫的最高qPCR流行率出现在杰克角和普伦蒂斯岛（分别为40%和48%），这两个地点都位于达马里斯科塔河河口。杰克角、普伦蒂斯岛、新草地河和韦斯卡格河记录了马里努斯派琴虫的最高qPCR流行率（32%-39%）。虽然2016年和2017年马里努斯派琴虫的qPCR流行率略有不同，但2016年切萨皮克派琴虫的qPCR流行率明显低于2017年（各年份所有地点分别为<20%和>60%）。在为期两年的研究中，杰克角（49%）、普伦蒂斯岛（44%）和新草地河（40%）的样本中，切萨皮克派琴虫的平均qPCR流行率值≥40%。这项研究强调，对寄生虫病进行大规模且持续的调查是贝类养殖业管理决策的基础，特别是在出现死亡事件时能够提供一个基线数据。
