Evidence of sarcocystid infection was investigated in samples of 16 penguins (Spheniscus. magellanicus), four Dominican gulls (Larus dominicanus) and two Chilean skuas (Stercorarius chilensis) found in Madalenas Islands, Chile, in 2017. Samples of skeletal muscle, cardiac muscle and brain from all birds were screened by a pan-sarcocystid nested-PCR targeting a short fragment of the gene encoding the small ribosomal unit (nPCR-18Sa). The only two positive samples by nPCR-18Sa, both from skuas, were tested by a nested-PCR directed to the internal transcribed spacer 1 (nPCR-ITS1), also a pan-sarcocystidae nested-PCR, and to a nested-PCR directed to the B1 gene (nPCR-B1), for the exclusive detection of Toxoplasma gondii. The two nPCR-18Sa-positive samples were nPCR-ITS1-positive and nPCR-B1-negative. The nPCR-ITS1 nucleotide sequences from the two skuas, which were identical to each other, were revealed closely related to homologous sequences of Sarcocystis halieti, species found in seabirds of northern hemisphere. Larger fragments of genes encoding 18S and partial sequences of genes coding for cytochrome oxidase subunit 1 were also analyzed, corroborating ITS1 data. The haplotypes found in the skuas are unprecedent and closely related to species that use birds as the definitive host. Further studies need to be carried out to detect, identify and isolate this parasite to understand the epidemiology of the infection and its impact on the health of marine fauna.

中文翻译：

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智利南部马格达莱纳岛海鸟中海藻类新单倍型的分子特征

2017年，在智利的马德雷纳群岛上发现了16只企鹅（Spheniscus。magellanicus），四只多米尼加海鸥（Larus dominicanus）和两只智利skuas（Stercorarius chilensis）样本中的囊藻感染证据。骨骼肌，心肌和通过针对所有编码小核糖体单位（nPCR-18Sa）的基因的短片段的泛囊藻巢式PCR筛选所有鸟类的大脑。nPCR-18Sa仅有的两个阳性样品，均来自斯夸斯州，通过针对内部转录间隔区1（nPCR-ITS1）（也属于泛囊藻科巢式PCR）和针对巢式PCR的巢式PCR进行测试到B1基因（nPCR-B1），专门用于检测弓形虫。两个nPCR-18Sa阳性样品为nPCR-ITS1阳性和nPCR-B1阴性。揭示了来自两个skuas的nPCR-ITS1核苷酸序列，它们彼此相同，与在北半球海鸟中发现的Sarcocystis halieti物种的同源序列密切相关。还分析了编码18S的较大基因片段和编码细胞色素氧化酶亚基1的基因的部分序列，证实了ITS1数据。在斯夸斯犬中发现的单倍型是史无前例的，并且与以鸟类为最终宿主的物种紧密相关。需要进行进一步的研究以检测，鉴定和分离该寄生虫，以了解感染的流行病学及其对海洋动物健康的影响。