Parasite genotype is a risk factor for Sarcocystis neurona-associated mortality in southern sea otters (Enhydra lutris nereis)

IF 2.3 3区医学 Q3 ECOLOGY

International Journal for Parasitology-Parasites and Wildlife Pub Date : 2026-04-01 Epub Date: 2025-12-06 DOI:10.1016/j.ijppaw.2025.101174

Devinn M. Sinnott , Melissa A. Miller , Elizabeth VanWormer , Francesca Batac , Katherine Greenwald , Colleen Young , Pádraig J. Duignan , Margaret E. Martinez , Cara L. Field , Michael D. Harris , Heather Harris , Mary E. Gomes , Michael J. Murray , Karen Shapiro

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引用次数: 0

Abstract

The protozoal parasites Sarcocystis neurona and Toxoplasma gondii are important causes of mortality for threatened southern sea otters (Enhydra lutris nereis) in California. Sarcocystis neurona causes more sea otter deaths than T. gondii and has caused two mortality events, yet S. neurona is comparatively understudied. Little is known about the role of parasite genotype on the outcome of infection (fatal versus non-fatal) for S. neurona-infected sea otters. The objective of this study was to evaluate the effect of parasite genotype in addition to host and environmental factors (animal age, sex, location, and season of stranding) on disease outcome in S. neurona-infected sea otters. A multilocus sequence typing (MLST) approach was used to characterize the S. neurona genotype in fatal (n = 92) and non-fatal (n = 33) sea otter infections. In the northern study region, the IIg/j genotype was more likely to result in fatal infections. In the southern study region, the Ia and Ib/c/d/gg genotypes were the dominant genotypes implicated in fatal infections and were responsible for mortality events that occurred in 2004 (Ib/c/d/gg) and 2021 (Ia). Subadult sea otters were more likely to die from S. neurona than adults. Stranding during the California wet season during peak rainfall events that facilitate land-to-sea flow of infective sporocysts may also play a role in fatal infection outcomes. These findings suggest that parasite genotype, as well as certain host and environmental factors, all contribute to disease outcome following S. neurona infection in southern sea otters.

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寄生虫基因型是南海獭神经元性肌囊虫相关死亡的危险因素。

原生动物寄生虫神经肌囊虫和刚地弓形虫是加利福尼亚濒危南海獭（Enhydra lutris nereis）死亡的重要原因。与弓形虫相比，神经元肌囊菌导致海獭死亡的人数更多，并造成了两次死亡事件，但神经元肌囊菌的研究相对不足。关于寄生虫基因型对神经索虫感染海獭感染结果（致死性与非致死性）的作用知之甚少。本研究的目的是评估除宿主和环境因素（动物年龄、性别、地点和搁浅季节）外，寄生虫基因型对感染S.神经元海獭疾病结局的影响。采用多位点序列分型（MLST）方法对致死性（n = 92）和非致死性（n = 33）海獭感染的神经藻基因型进行了分析。在北部研究区，IIg/j基因型更易导致致死性感染。在南部研究区域，Ia和Ib/c/d/gg基因型是与致命性感染相关的主要基因型，并与2004年（Ib/c/d/gg）和2021年（Ia）发生的死亡事件有关。与成年海獭相比，亚成年海獭更容易死于神经水母。在加州雨季的高峰降雨期间搁浅，促进了传染性孢子囊从陆地向海洋的流动，也可能在致命的感染结果中发挥作用。这些发现表明，寄生虫基因型以及某些宿主和环境因素都有助于南海獭神经索菌感染后的疾病结局。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

International Journal for Parasitology-Parasites and Wildlife Medicine-Infectious Diseases

CiteScore

3.80

自引率

5.60%

发文量

113

审稿时长

45 days

期刊介绍： The International Journal for Parasitology: Parasites and Wildlife (IJP-PAW) publishes the results of original research on parasites of all wildlife, invertebrate and vertebrate. This includes free-ranging, wild populations, as well as captive wildlife, semi-domesticated species (e.g. reindeer) and farmed populations of recently domesticated or wild-captured species (e.g. cultured fishes). Articles on all aspects of wildlife parasitology are welcomed including taxonomy, biodiversity and distribution, ecology and epidemiology, population biology and host-parasite relationships. The impact of parasites on the health and conservation of wildlife is seen as an important area covered by the journal especially the potential role of environmental factors, for example climate. Also important to the journal is ''one health'' and the nature of interactions between wildlife, people and domestic animals, including disease emergence and zoonoses.