Andreou D, Gozlan R E, Paley R
Centre for Ecology and Hydrology, Mansfield Road, Oxford, Oxfordshire OX1 3SR, UK.
J Parasitol. 2009 Dec;95(6):1539-41. doi: 10.1645/GE-2124.1.
The majority of pathogens that cause high host mortalities are capable of infecting more than 1 host species. One characteristic of pathogens, which enables infection of multiple hosts, is the existence of free-living infectious stages, e.g., zoospores that are produced in vast numbers. Understanding the influence of environmental factors, particularly temperature, on the production and survival of these free-living stages is key to predicting future spread and emergence of disease. The rosette agent, Sphaerothecum destruens, is a significant multi-host intracellular fish parasite, with an obligate intracellular spore stage and a free-living (extracellular), potentially infectious, zoospore stage. It has caused high mortalities in endangered and commercially important fish species. Here we investigate the influence of temperature on S. destruens zoospore production and longevity. Our results indicate a wide temperature tolerance of the spore and zooflagellate stage with later onset and longer lifespan of zoospores at lower temperatures. This has important implications for the environmental persistence of S. destruens and provides additional information on the pathogen's life cycle with direct implications for S. destruens risk assessment.
大多数导致宿主高死亡率的病原体能够感染不止一种宿主物种。病原体能够感染多种宿主的一个特征是存在自由生活的感染阶段，例如大量产生的游动孢子。了解环境因素，特别是温度，对这些自由生活阶段的产生和存活的影响是预测疾病未来传播和出现的关键。莲座病原体毁灭球囊菌是一种重要的多宿主细胞内鱼类寄生虫，具有专性细胞内孢子阶段和自由生活（细胞外）、可能具有传染性的游动孢子阶段。它已在濒危和具有商业重要性的鱼类物种中导致高死亡率。在这里，我们研究温度对毁灭球囊菌游动孢子产生和寿命的影响。我们的结果表明，孢子和游动鞭毛体阶段具有广泛的温度耐受性，在较低温度下，游动孢子的起始时间较晚且寿命较长。这对毁灭球囊菌在环境中的持久性具有重要意义，并提供了有关该病原体生命周期的更多信息，对毁灭球囊菌风险评估具有直接影响。
