Department of Veterinary Medicine, Federal University of Paraná, Rua dos Funcionários 1540, CEP 80035-050, Curitiba, Paraná, Brazil.
Santos Basin Beach Monitoring Project (PMP-BS), Seabird Rehabilitation Laboratory, University of Vale do Itajaí, Rua Maria Emília da Costa, CEP: 88-385-00090, Armação, Penha, Santa Catarina, Brazil.
Parasitol Int. 2022 Oct;90:102595. doi: 10.1016/j.parint.2022.102595. Epub 2022 May 10.
Sarcocystis spp. are cyst forming apicomplexan parasites that infect many vertebrates including birds. Sarcocystis spp. infection was investigated in tissue samples (pectoral muscles, heart, and brain) of 47 dead seabirds collected from the coastline of Santa Catarina State SC - Brazil, between August 2019 and March 2020. A portion of each tissue was fixed in 10% buffered formalin for histopathologic analysis while DNA was extracted from another portion and screened using nested-PCR targeting ITS1. Based on molecular analysis, Sarcocystis spp. were identified in 15/47 (31.9%) seabirds of five species, kelp gull (Larus dominicanus), manx shearwater (Puffinus puffinus), neotropic cormorant (Phalacrocorax brasilianus), brown booby (Sula leucogaster) and great skua (Stercorarius skua). Microscopically visible sarcocysts were observed only in the pectoral muscle of four seabirds 8.5% (4/47), while in one brown booby, sarcocysts were seen in both pectoral and cardiac muscles. Two types of sarcocysts, thin walled (≤1 μm) and thick-walled (≥ 2 μm) were identified. Based on ITS1 sequence comparison, S. halieti, S. falcatula and three not yet described Sarcocystis spp. were detected. Phylogenetically, S. falcatula isolates were classified as two distinct clusters. This is the first confirmation of S. halieti in seabird's species in South America and S. falcatula in birds of the order Charadriiformes. Further molecular studies are needed to understand the epidemiology of the Sarcocystis spp. infection and its impact on the health of seabirds.
肌肉小囊虫属（Sarcocystis spp.）是形成包囊的顶复门原虫寄生虫，感染许多包括鸟类在内的脊椎动物。2019 年 8 月至 2020 年 3 月期间，在巴西圣卡塔琳娜州（Santa Catarina State SC）的海岸线收集了 47 只死海鸟的组织样本（胸肌、心脏和大脑），对这些组织样本中的 Sarcocystis spp. 感染情况进行了调查。一部分组织用 10%缓冲福尔马林固定，用于组织病理学分析，而另一部分组织的 DNA 则被提取出来，并使用针对 ITS1 的巢式 PCR 进行筛选。基于分子分析，在 47 只海鸟中的 15 只（31.9%）、5 种海鸟中鉴定出肌肉小囊虫属（Sarcocystis spp.），这 5 种海鸟分别为黑背鸥（Larus dominicanus）、角嘴海雀（Puffinus puffinus）、南美鸬鹚（Phalacrocorax brasilianus）、褐鹈鹕（Sula leucogaster）和虎头海雕（Stercorarius skua）。仅在 4 只海鸟的胸肌中观察到肉眼可见的包囊，占 8.5%（4/47），而在 1 只褐鹈鹕中，包囊同时存在于胸肌和心肌中。鉴定出两种类型的包囊，薄壁（≤1μm）和厚壁（≥2μm）。基于 ITS1 序列比较，检测到 S. halieti、S. falcatula 和三种尚未描述的肌肉小囊虫属（Sarcocystis spp.）。系统发育分析表明，S. falcatula 分离株分为两个不同的聚类。这是首次在南美的海鸟物种中确认 S. halieti，也是首次在鸻形目鸟类中确认 S. falcatula。需要进一步的分子研究来了解肌肉小囊虫属（Sarcocystis spp.）感染的流行病学及其对海鸟健康的影响。
