An atypical genotype of Toxoplasma gondii as a cause of mortality in Hector's dolphins (Cephalorhynchus hectori)
An atypical genotype of Toxoplasma gondii as a cause of mortality in Hector's dolphins (Cephalorhynchus hectori)
复制标题
DOI：
10.1016/j.vetpar.2012.11.001
复制
发表时间：
2013-02-18
影响因子：
2.6
通讯作者：
Hunter, S. A.
中科院分区：
文献类型：
--
作者：
Roe, W. D.;Howe, L.;Hunter, S. A.
赫克托海豚 (Cephalorhynchus hectori) 是新西兰特有的小型濒危沿海物种。人为因素，特别是渔网中的意外捕获，被认为是对该物种生存的最大威胁。传染病作为死亡原因的作用此前尚未得到充分研究。这项研究调查了赫克托海豚的弓形虫感染情况，发现 28 只海豚中有 7 只 (25%) 死于传播性弓形虫病，其中包括 3 只毛伊海豚（一种极度濒危亚种）中的 2 只。另外 10 只海豚的一个或多个组织经 PCR 检测呈弓形虫 DNA 阳性。基因分型显示，8 个成功扩增的分离株中有 7 个是非典型 II 型基因型。死亡病例的肺部（n = 7）、淋巴结（n = 6）、肝脏（n = 4）和肾上腺（n = 3）有坏死和出血性病变。速殖子和组织囊肿存在于其他器官中，包括大脑 (n = 5)、心脏 (n = 1)、胃 (n = 1) 和子宫 (n = 1)，相关炎症反应最小。一只海豚在存在大量上皮内速殖子的情况下患有明显的化脓性子宫炎。没有海豚患有潜在的麻疹病毒感染。这项研究提供了第一个证据，表明传染性病原体可能对该物种的种群数量下降很重要，并强调需要进一步研究弓形虫生物体进入全球海洋环境的途径。 (c) 2012 Elsevier B.V. 保留所有权利。
Hector's dolphins (Cephalorhynchus hectori) are a small endangered coastal species that are endemic to New Zealand. Anthropogenic factors, particularly accidental capture in fishing nets, are believed to be the biggest threat to survival of this species. The role of infectious disease as a cause of mortality has not previously been well investigated. This study investigates Toxoplasma gondii infection in Hector's dolphins, finding that 7 of 28 (25%) dolphins examined died due to disseminated toxoplasmosis, including 2 of 3 Maui's dolphins, a critically endangered sub-species. A further 10 dolphins had one or more tissues that were positive for the presence of T. gondii DNA using PCR. Genotyping revealed that 7 of 8 successfully amplified isolates were an atypical Type II genotype. Fatal cases had necrotising and haemorrhagic lesions in the lung (n = 7), lymph nodes (n = 6), liver (n = 4) and adrenals (n = 3). Tachyzoites and tissue cysts were present in other organs including the brain (n = 5), heart (n = 1), stomach (n = 1) and uterus (n = 1) with minimal associated inflammatory response. One dolphin had a marked suppurative metritis in the presence of numerous intra-epithelial tachyzoites. No dolphins had underlying morbillivirus infection. This study provides the first evidence that infectious agents could be important in the population decline of this species, and highlights the need for further research into the route of entry of T. gondii organisms into the marine environment worldwide. (c) 2012 Elsevier B.V. All rights reserved.