Data_Sheet_2_Updates on Ecology and Life Cycle of Sulcascaris sulcata (Nematoda: Anisakidae) in Mediterranean Grounds: Molecular Identification of Larvae Infecting Edible Scallops.PDF

Sulcascaris sulcata is a nematode parasite of sea turtles, widespread in neritic foraging grounds with variable prevalence, reaching 30% in loggerhead turtles Caretta caretta feeding in northern Adriatic Sea. Ulcerative gastritis associated to high intensity of infection is reported in this host species. The life cycle of S. sulcata has been elucidated in Australian and American waters, demonstrating the ability of the species of infecting a wide range of intermediate hosts, represented by bivalve and gastropod molluscs. During regular sanitary inspections, nematode larvae were found within the adductor muscle of Pecten jacobeus and Aequipecten opercularis collected from the Northern Adriatic Sea. Morphological and molecular analyses were performed for the identification of larvae, and molecular data were obtained from adult S. sulcata as well. Analysis of the sequences of ITS fragment, and mitochondrial genes cox1 and cox2, revealed high genetic similarity among all the samples, and no geographical clustering was observed between adult parasites collected in Adriatic and Tyrrhenian Seas. A common allele pool was detected also between the two developmental stages, included larvae from Pecten and Aequipecten. The comparison with other members of the family Anisakidae demonstrated that S. sulcata formed a clear monophyletic cluster. This study reports the first identification of intermediate hosts for S. sulcata within the Mediterranean Sea. Infection in edible scallops justifies the exclusion of the product from the market and zoonotic potential of larvae of this anisakid nematode are yet to be completely excluded. Fidelity of sea turtles to selected foraging grounds, such as the Northern Adriatic shelf, warrants the life cycle of S. sulcata to perpetrate in the area; at the same time, long distance migrations of individuals justify the dispersal of infecting elements over the Mediterranean basin, regardless of turtles' origin.

沟棘蛔虫（Sulcascaris sulcata）是一种寄生于海龟的线虫，广泛分布于近岸觅食生境，感染率存在显著差异，在北亚得里亚海觅食的赤蠵龟（Caretta caretta）中感染率可达30%。该宿主物种中曾报道过与高感染强度相关的溃疡性胃炎。沟棘蛔虫的生活史已在澳大利亚与美国海域得到阐明，证实该物种可感染以双壳类和腹足类软体动物为代表的多种中间宿主。在常规卫生检疫工作中，研究人员从北亚得里亚海采集的海湾扇贝（Pecten jacobeus）和欧洲海扇蛤（Aequipecten opercularis）的闭壳肌内检出了线虫幼虫。研究人员通过形态学与分子生物学分析对幼虫进行了鉴定，同时也获取了沟棘蛔虫成虫的分子数据。对ITS片段、线粒体基因cox1与cox2的序列分析显示，所有样本间的遗传相似度极高，且在亚得里亚海与第勒尼安海采集的成虫样本之间未观察到地理聚类现象。在两个发育阶段（包括来自海湾扇贝与欧洲海扇蛤的幼虫）之间，同样检测到了共同的等位基因库。与异尖科（Anisakidae）其他类群的比对结果显示，沟棘蛔虫形成了一个清晰的单系簇群。本研究首次在地中海海域报道了沟棘蛔虫的中间宿主。可食用扇贝的感染情况使得该产品需从市场中下架；同时该异尖科线虫幼虫的人畜共患潜力仍未被完全排除。海龟对选定觅食生境（如北亚得里亚海大陆架）的栖息忠实性，使得沟棘蛔虫的生活史得以在该区域延续；与此同时，海龟个体的长距离迁徙使得感染性媒介能够在地中海盆地范围内扩散，而不受其起源地的限制。