Department of Biosciences, Swansea University, Singleton Park, Swansea SA2 8PP, United Kingdom.
J Eukaryot Microbiol. 2011 Sep-Oct;58(5):446-51. doi: 10.1111/j.1550-7408.2011.00570.x. Epub 2011 Aug 18.
Crustaceans worldwide are infected with alveolate parasites of the genus Hematodinium, causing substantial losses to langoustine and crab fisheries. The distinct seasonality in Hematodinium occurrence in their decapod hosts, as well as unsuccessful attempts at transmission, suggest the existence of life stages outside their benthic crustacean hosts. We used a nested polymerase chain reaction method to detect Hematodinium rDNA in the environment and in potential alternative hosts. Environmental samples from the Clyde Sea, Scotland, were screened during the April release of dinospores and during June and August, when infection prevalence is rare in benthic crustaceans. Hematodinium rDNA was amplified in 15% (14/94) of isolated langoustine larvae, and in 12% (13/111) of crab larvae. In addition, Hematodinium rDNA was present in mixed plankton samples devoid of decapod larvae, but including the 2 μm-10 mm fraction of particulate organic matter in the water column, containing phytoplankton and other zooplankton. These results indicate that Hematodinium occurs in the water column and is harboured by planktonic organisms, including larval stages of the crustacean hosts, when infections are at their lowest in adult hosts.
甲壳类动物在全球范围内受到血细胞虫属的微孢子虫的感染，这对小龙虾和蟹类渔业造成了巨大的损失。血细胞虫在其十足目宿主中的明显季节性出现，以及在传播方面的不成功尝试，表明它们在底栖甲壳类宿主之外存在生活阶段。我们使用巢式聚合酶链反应方法来检测环境中和潜在替代宿主中的血细胞虫 rDNA。在苏格兰克莱德海的环境样本中，在四月释放孢子期间以及在六月和八月（此时底栖甲壳类动物的感染率很低）进行了筛选。在分离的小龙虾幼虫中，有 15%（14/94）扩增出了血细胞虫 rDNA，在螃蟹幼虫中，有 12%（13/111）扩增出了血细胞虫 rDNA。此外，在缺乏十足目幼虫但含有水柱中浮游植物和其他浮游动物的 2μm-10mm 粒状有机物质部分的混合浮游生物样本中也存在血细胞虫 rDNA。这些结果表明，当宿主成年个体中的感染处于最低水平时，血细胞虫存在于水柱中，并由浮游生物宿主，包括其甲壳类宿主的幼虫阶段携带。
