Abstract:
Obligatory endoparasitic mites of the genera Halarachne Allman, 1847 and Orthohalarachne Newell, 1947 (Acari: Halarachnidae) parasitize different segments of the respiratory tract of marine mammals, including pinnipeds and sea otters, and infestations can cause asymptomatic to serious respiratory diseases. However, knowledge on biology, pathogenic potential and occurrence of halarachnid mites infesting pinnipeds, especially in captivity, is scarce. A two-year-old South American sea lion (Otaria flavescens Shaw, 1800) male, born and held at the Vienna Zoo, was anesthesized for routine pre-transport examinations, including computed tomography, bronchoalveolar lavage, and blood sampling. During the final phase of general anesthesia, the individual abruptly became apneic and died despite all attempts at resuscitation. At necropsy, 45 highly motile whitish millimeter-sized structures were macroscopically detected in the trachea, bifurcatio tracheae and main bronchi and were identified as adult stages of Orthohalarachne diminuata Doetschman, 1944 following morphological descriptions. After trepanation of the nasal cavity and sinus paranasalis, a total of 407 larval and 3 nymphal specimens distributed in clusters were detected. Macroscopically, sinus mucosa showed hyperemia and multiple petechial hemorrhages. Histopathological analyses of paranasal sinuses revealed mite cross-sections surrounded by sanioserous exudate and epithelial exfoliation. For the first time, O. diminuata was molecularly characterized and phylogenetically analyzed based on its 16S rDNA. Our study constitutes the first record of a severe O. diminuata infestation in captive O. flavescens and one of the few host-parasite records in general. We present clinical data and pathological results, the first scanning electron microscopic images of a O. diminuata larval stage and discuss the etiology of this autochthonous infestation, possible transmission pathways and detrimental effects. Further studies on biology and pathogenic effects of halarachnid mites, as well as on the development of non-invasive sampling techniques are essentially required for a better understanding of (ortho-)halarachnosis in pinnipeds held in zoological gardens.
摘要:
HalarachneAllman属的强制性内寄生虫螨,1847年和OrthohalarachneNewell,1947年(Acari:Halarachnidae)寄生了海洋哺乳动物呼吸道的不同部分,包括针脚和海獭,感染会导致无症状的严重呼吸系统疾病。然而,生物学知识,致病潜力和halarachnid螨的发生,尤其是在被囚禁的时候,是稀缺的。一只两岁的南美海狮(OtariaflavescensShaw,1800)男性,出生并在维也纳动物园举行,进行常规运输前检查的麻醉,包括计算机断层扫描,支气管肺泡灌洗,和血液采样。在全身麻醉的最后阶段,尽管尝试了所有复苏措施,但该人突然出现呼吸暂停并死亡。尸检时,在气管中宏观检测到45个高度活动的白色毫米大小的结构,气管气管和主支气管被确定为小型直头肌的成年阶段,1944年遵循形态学描述。鼻腔和副鼻窦钻孔后,共检测到407个幼虫和3个若虫标本,成簇分布。宏观上,鼻窦粘膜表现为充血和多发点状出血。鼻旁窦的组织病理学分析显示,螨的横截面被沙质渗出液和上皮脱落包围。第一次,O.diminuata根据其16SrDNA进行了分子表征和系统发育分析。我们的研究构成了圈养的O.lavescens中严重的O.diminuata侵染的第一个记录,也是一般的少数宿主寄生虫记录之一。我们提供临床资料和病理结果,第一次扫描电子显微镜图像的一个小的幼体阶段,并讨论这种自生侵染的病因,可能的传播途径和有害影响。进一步研究Halachnid螨的生物学和致病作用,以及非侵入性采样技术的发展,基本上需要更好地了解动物园中的in足动物的(正)halarachness。