Laboratory of Animal Pathology, Department of Preventive Veterinary Medicine, Universidade Estadual de Londrina, Paraná, Brazil; Comparative Pathology Shared Resources Laboratory, Masonic Cancer Center, University of Minnesota, Saint Paul, MN, USA.
Laboratory of Animal Pathology, Department of Preventive Veterinary Medicine, Universidade Estadual de Londrina, Paraná, Brazil.
Microb Pathog. 2020 Dec;149:104497. doi: 10.1016/j.micpath.2020.104497. Epub 2020 Sep 8.
Diphtheric aspergillosis tracheitis is an uncommon syndrome described in human pathology, usually associated with immunosuppression in the affected individuals. Interestingly, no comparative/equivalent cases were found in domestic animals. This report describes the pathological and mycological findings associated with diphtheric aspergillosis tracheitis in an immunocompromised calf. The main pathological findings were diphtheric tracheitis and rhinitis, and necrotizing ruminitis associated with intralesional septate, acute branching fungal hyphae consistent with Aspergillus spp. Mycological culture and isolation confirmed the fungal hyphae as A. fumigatus due to characteristic features. Immunohistochemistry (IHC) assays identified intralesional antigens of bovine viral diarrhea virus (BVDV) and malignant catarrhal fever virus (MCFV) at the trachea and small intestine; IHC detected intralesional antigens of bovine alphaherpesvirus 1 (BoHV-1) only at the trachea. These findings confirmed the simultaneous occurrence of A. fumigatus with concomitant infections due to BVDV, MCFV, and BoHV-1 in this calf. Since ovine gammaherpesvirus-2 (OvHV-2) is the cause of MCF in Brail, it is likely that the intralesional MCFV antigens identified were those of OvHV-2. In this case, disseminated aspergillosis was probably associated with the undeveloped immunological status of the calf that was further impaired due to the combined immunodepressive effects of BVDV and BoHV-1 infections. Although BVDV and BoHV-1 are infectious disease pathogens frequently associated with the development of bovine respiratory disease (BRD) in feedlot and dairy cattle, the identification of intralesional OvHV-2-like antigens in several parts of the lungs suggest that this MCFV also played a role in the BRD-associated lesions identified in this calf.
白喉性曲霉菌气管炎是人类病理学中描述的一种不常见综合征，通常与受影响个体的免疫抑制有关。有趣的是，在家畜中没有发现类似的病例。本报告描述了一例免疫功能低下小牛的白喉性曲霉菌气管炎的病理和真菌学发现。主要的病理发现是白喉性气管炎和鼻炎，以及坏死性鼻炎，与病灶内分隔的、急性分枝真菌菌丝有关，这些真菌菌丝与曲霉菌属一致。真菌学培养和分离证实了真菌菌丝为烟曲霉，这是由于其特征性表现。免疫组织化学（IHC）检测在气管和小肠中鉴定出牛病毒性腹泻病毒（BVDV）和恶性卡他热病毒（MCFV）的病灶内抗原；IHC 仅在气管中检测到牛α疱疹病毒 1（BoHV-1）的病灶内抗原。这些发现证实了在这头小牛中，烟曲霉与 BVDV、MCFV 和 BoHV-1 同时发生的伴随感染。由于绵羊γ疱疹病毒-2（OvHV-2）是巴西 MCF 的病原体，因此，在病灶中鉴定出的 MCFV 抗原很可能是 OvHV-2。在这种情况下，播散性曲霉菌病可能与小牛尚未发育成熟的免疫状态有关，而 BVDV 和 BoHV-1 感染的联合免疫抑制作用进一步削弱了这种免疫状态。尽管 BVDV 和 BoHV-1 是经常与牛呼吸道疾病（BRD）相关的传染病病原体，但在肺部的几个部位鉴定出病灶内的 OvHV-2 样抗原表明，这种 MCFV 也在该小牛的 BRD 相关病变中发挥了作用。
