Molecular identification and histological aspects of Renicola sloanei (Digenea: Renicolidae) in Puffinus puffinus (Procellariiformes): a first record

Abstract Renicolids are parasites that inhabit the renal tubules and ureters of molluscivorous and piscivorous birds. Puffinus puffinus is a migratory seabird that was identified as the definitive host of Renicola spp. Studies focusing on the renicolid species and the resulting renal lesions are valuable for their association with causes of stranding in seabirds. The aim of this study was to identify the renicolid trematodes and evaluate the histological findings in two P. puffinus stranded on the coast of Paraná state, Brazil. The parasites were evaluated by histologic, ultrastructural and molecular assays, while tissue changes were analyzed by histologic methods. The morphological and morphometrical characteristics of the parasites, along with polymerase chain reaction and sequencing assays (ribosomal and mitochondrial regions), identified the species as Renicola sloanei. The results also suggest that this helminth can be the adult form of Cercaria pythionike. The dilation of collecting ducts was the main histological finding in the kidneys. In conclusion, R. sloanei was identified, and for the first time, P. puffinus was described as a host of this digenean inducing mild renal changes.

摘要：肾科吸虫（Renicolids）是一类寄生于软体动物食性及鱼类食性鸟类的肾小管与输尿管内的寄生虫。曳尾鹱（Puffinus puffinus）是一种迁徙性海鸟，已被确定为肾科吸虫（Renicola spp.）的终末宿主。针对肾科吸虫物种及其引发的肾脏病变的研究，因其与海鸟搁浅的病因存在关联而具有重要研究价值。本研究旨在对巴西巴拉那州沿岸搁浅的2只曳尾鹱（Puffinus puffinus）体内的肾科吸虫进行鉴定，并评估其组织病理学特征。研究通过组织学、超微结构及分子生物学方法对寄生虫进行检测，同时采用组织学方法分析宿主的组织病变情况。结合寄生虫的形态学与形态测量学特征，以及聚合酶链式反应（PCR）及测序分析（核糖体与线粒体基因区域）结果，确定该物种为斯隆肾吸虫（Renicola sloanei）。研究结果同时表明，该蠕虫可能为毕氏尾蚴（Cercaria pythionike）的成虫阶段。肾脏组织的主要病理学表现为集合管扩张。综上，本研究成功鉴定出斯隆肾吸虫（R. sloanei），并首次将曳尾鹱（Puffinus puffinus）报道为该复殖吸虫的宿主，该寄生虫可引发轻度肾脏病变。