Cerezo Argiñe, Quesada-Canales Oscar, Sierra Eva, Díaz-Delgado Josué, Fernández Antonio, Henningson Jamie, Arbelo Manuel
Department of Diagnostic Medicine and Pathobiology, Kansas State Veterinary Diagnostic Laboratory, 1800 Denison Avenue, Manhattan, KS 66506, USA.
Dis Aquat Organ. 2018 Sep 10;130(2):153-158. doi: 10.3354/dao03268.
We report the gross and microscopic findings and molecular identification of fungal hyphate infection in a juvenile female Atlantic spotted dolphin Stenella frontalis found dead off Arguineguin, Gran Canaria (Canary Islands, Spain). On necropsy examination, the animal had a large cranial intrathoracic mass and multiple variably-sized nodules throughout the larynx and trachea that obliterated the lumen. Microscopically, the masses were composed of abundant pyogranulomatous inflammation with numerous fungal hyphae. These were pauciseptate (coenocytic) and had non-parallel walls, non-dichotomous irregular to right angle branching, and bulbous dilations. PCR analysis from these inflammatory foci yielded Rhizopus arrhizus (syn. R. oryzae). This fungal pathogen is often ascribed to opportunistic infections in immunosuppressed humans and animals. In the present case, a potential cause for immunosuppression was not identified; PCR analysis for cetacean morbillivirus was negative. Herein, we report the first confirmed case of R. arrhizus infection in a free-living Atlantic cetacean. These findings add to the body of knowledge on fungal disease in cetaceans in general and, in particular, in odontocetes, where respiratory involvement is common.
我们报告了在西班牙加那利群岛大加那利岛阿尔吉内金附近发现死亡的一只幼年雌性大西洋斑点海豚（宽吻额斑海豚）体内真菌丝感染的大体和微观检查结果以及分子鉴定情况。尸检时，该动物颅内胸腔有一个大肿块，整个喉部和气管有多个大小不一的结节，使管腔闭塞。显微镜下，肿块由大量脓性肉芽肿性炎症组成，并伴有大量真菌菌丝。这些菌丝少隔（多核），壁不平行，呈不规则至直角分支，且有球状膨大。对这些炎症病灶进行的PCR分析显示为少根根霉（同义词：米根霉）。这种真菌病原体常被认为与免疫抑制的人和动物的机会性感染有关。在本病例中，未发现免疫抑制的潜在原因；对鲸类麻疹病毒的PCR分析结果为阴性。在此，我们报告了首例在自由生活的大西洋鲸类动物中确诊的少根根霉感染病例。这些发现丰富了关于鲸类动物真菌病的知识体系，尤其是齿鲸类，其呼吸系统受累较为常见。
