Sabry Rachel Costa, Rosa Rafael Diego, Magalhães Aimê Rachel Magenta, Barracco Margherita Anna, Gesteira Tereza Cristina Vasconcelos, da Silva Patricia Mirella
Instituto de Ciências do Mar, Universidade Federal do Ceará, P.O. Box 52756, Fortaleza, CE, Brazil.
Dis Aquat Organ. 2009 Dec 22;88(1):13-23. doi: 10.3354/dao02136.
Protozoan parasites of the genus Perkinsus are considered important pathogens responsible for mass mortalities in several mollusk species worldwide. In the present study we describe for the first time a parasite of the genus Perkinsus infecting the mangrove oyster Crassostrea rhizophorae from the Brazilian coast. Prevalence of this parasite was low in the Pacoti River estuary (Ceará, northeast Brazil) and absent in oysters from southern Brazil. Oyster gill and rectum tissues incubated in Ray's fluid thioglycollate medium (RFTM) revealed the presence of spherical hypnospores (5 to 55 microm diam.). Histological analysis showed the occurrence of typical signet-ring trophozoites and schizonts (3 to 6 microm diam.) infecting connective tissues of several organs and digestive epithelia. PCR assays specific to the genus Perkinsus, followed by cloning and sequencing of the internal transcribed spacer (ITS) region of the ribosomal ribonucleic acid (rRNA) gene complex, confirmed a close phylogenetic relationship between Brazilian Perkinsus sp. and P. beihaiensis infecting Chinese oysters.
帕金虫属的原生动物寄生虫被认为是导致全球多种软体动物大量死亡的重要病原体。在本研究中，我们首次描述了一种感染巴西海岸红树林牡蛎（Crassostrea rhizophorae）的帕金虫属寄生虫。该寄生虫在帕科蒂河河口（巴西东北部塞阿拉州）的感染率较低，而在巴西南部的牡蛎中未发现。在雷氏硫乙醇酸盐培养基（RFTM）中培养的牡蛎鳃和直肠组织显示存在球形休眠孢子（直径5至55微米）。组织学分析表明，出现了典型的印戒滋养体和裂殖体（直径3至6微米），感染了多个器官的结缔组织和消化上皮。针对帕金虫属的PCR检测，随后对核糖体核糖核酸（rRNA）基因复合体的内部转录间隔区（ITS）进行克隆和测序，证实了巴西帕金虫属物种与感染中国牡蛎的北海帕金虫之间存在密切的系统发育关系。
