Rivera-Luna Helena, Kniha Edwin, Muñoz Pamela, Painean Javier, Balfanz Folko, Hering-Hagenbeck Stephan, Prosl Heinrich, Walochnik Julia, Taubert Anja, Hermosilla Carlos, Ebmer David
Institute of Parasitology, Biomedical Research Center Seltersberg, Justus Liebig University Giessen, Schubertstr. 81, 35392, Giessen, Germany.
Institute of Specific Prophylaxis and Tropical Medicine, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Kinderspitalg. 15, 1090, Vienna, Austria.
Int J Parasitol Parasites Wildl. 2023 Jun 3;21:192-200. doi: 10.1016/j.ijppaw.2023.06.001. eCollection 2023 Aug.
Respiratory mites of the genera and (Acari: Halarachnidae) are causative agents of nasopharyngeal/nasopulmonary acariasis in pinnipeds and sea otters. Until now, these endoparasitic mites were mainly diagnosed via necropsies and invasive procedures. So far, non-invasive diagnostic techniques have neither been developed nor applied in free-ranging pinnipeds. In the current study, we aimed to evaluate the halarachnid mite infestation status of free-ranging "urban" South American sea lions in the city of Valdivia, Chile. Therefore, non-invasive sampling methods were used in the current study, e. g. by observation-based sampling of freshly expectorated nasal mucus in the animal environment. Further, collection devices were developed for target-oriented sampling of sneezed nasal mucus, including sterile petri dishes and stretched clingfilms mounted on telescopic rods. Applying these techniques, 26 individual sputum samples were collected. 11.5% of sputum samples proved positive for halarachnid larvae (in total, n = 7), which were morphologically identified as (n = 2) or (n = 5). In one of the individual sea lion mucus samples, both species were detected, thereby confirming a patent co-infestation . 16S rDNA-based molecular identification of individual spp. larvae confirmed morphological findings. For the first time, we here molecularly characterized spp. on the basis of three gene regions [18S, 28S and the internal transcribed spacer 1 (ITS1)]. Overall, current data include the successful application of non-invasive techniques to sample halarachnid mites from free-ranging synanthropic pinnipeds and contribute to the current knowledge on respiratory mites infesting South American sea lions by combining morphological and molecular methods to overcome challenges in species identification. This study should further serve as baseline study and calls for more research on occurrence, biology and health implications of orthohalarachnosis in free-living as well as captive pinnipeds.
属和属的呼吸道螨类（蜱螨亚纲：海蛛螨科）是鳍足类动物和海獭鼻咽/鼻肺螨病的病原体。到目前为止，这些体内寄生虫螨主要通过尸检和侵入性程序进行诊断。迄今为止，非侵入性诊断技术尚未在自由放养的鳍足类动物中得到开发和应用。在当前的研究中，我们旨在评估智利瓦尔迪维亚市自由放养的“城市”南美海狮的海蛛螨感染状况。因此，本研究采用了非侵入性采样方法，例如通过在动物环境中对新鲜咳出的鼻黏液进行基于观察的采样。此外，还开发了用于有针对性地采集打喷嚏时喷出的鼻黏液的收集装置，包括无菌培养皿和安装在伸缩杆上的拉伸保鲜膜。应用这些技术，共收集了26份个体痰液样本。11.5%的痰液样本被证明海蛛螨幼虫呈阳性（总计n = 7），这些幼虫在形态上被鉴定为属（n = 2）或属（n = 5）。在一份个体海狮黏液样本中，检测到了两种属的螨，从而证实了明显的混合感染。基于16S rDNA对个体属螨幼虫进行的分子鉴定证实了形态学研究结果。我们首次在此基于三个基因区域[18S、28S和内部转录间隔区1（ITS1）]对属螨进行了分子特征分析。总体而言，当前数据包括成功应用非侵入性技术从自由放养的近人类鳍足类动物中采集海蛛螨样本，并通过结合形态学和分子方法克服物种鉴定方面的挑战，为目前关于感染南美海狮的呼吸道螨的知识做出了贡献。本研究应进一步作为基线研究，并呼吁对自由生活以及圈养鳍足类动物中正海蛛螨病的发生、生物学特性及其对健康的影响开展更多研究。
