Knowles Susan, Berlowski-Zier Brenda M, Justice-Allen Anne, Bodenstein Barbara L, Lorch Jeffrey M
U.S. Geological Survey, 6006 Schroeder Road, Madison, WI 53711, USA.
Arizona Game and Fish Department, 5000 W. Carefree Highway, Phoenix, AZ 85086, USA.
Pathogens. 2025 Jul 15;14(7):698. doi: 10.3390/pathogens14070698.
spp. are opportunistic pathogens of humans, domestic animals, and wildlife that can cause high levels of morbidity and mortality. Here, we present a unique case of nocardial airsacculitis in a free-ranging mallard () from Arizona, USA, and compare it to the hosts, geographic distribution, diagnostic methodology, and infection site of known nocardiosis cases in birds. A gross necropsy, histopathology, and bacterial culture were performed. There were no gross findings associated with the nocardiosis. Histopathology showed multiple granulomas expanding the air sac with intralesional filamentous bacteria that were Grocott's methenamine silver-positive, Fite-Faraco and Ziehl-Neelsen acid-fast, positive with the Periodic acid-Schiff reaction, and variably Gram-positive. The organism was isolated in culture and identified as based on the sequencing of a 463 bp portion of the 16S rRNA gene. While reports of nocardiosis in the class Aves are rare and some are possibly misdiagnosed due to limited diagnostics, cases are reported globally, sometimes resulting in epizootics. More information is needed to understand whether immunosuppression plays a role in disease development in birds. Known to be an emerging pathogen in humans, can be considered as a differential diagnosis for pulmonary and potentially cutaneous or disseminated infections in birds.
某些放线菌属物种是人类、家畜和野生动物的机会致病菌，可导致高发病率和死亡率。在此，我们报告了一例来自美国亚利桑那州的自由放养绿头鸭发生诺卡氏菌气囊炎的独特病例，并将其与鸟类已知诺卡氏菌病病例的宿主、地理分布、诊断方法及感染部位进行比较。进行了大体尸检、组织病理学检查和细菌培养。未发现与诺卡氏菌病相关的大体病变。组织病理学显示多个肉芽肿使气囊扩张，病灶内有丝状细菌，这些细菌经Grocott六胺银染色呈阳性、Fite-Faraco染色和齐尔-尼尔森抗酸染色呈阳性、过碘酸-希夫反应呈阳性，且革兰氏染色结果不定。该菌在培养中分离出来，并根据16S rRNA基因463 bp片段的测序鉴定为[具体菌种]。虽然鸟类诺卡氏菌病的报告很少，而且由于诊断方法有限，有些可能被误诊，但全球都有病例报告，有时还会引发 epizootics（动物流行病）。需要更多信息来了解免疫抑制是否在鸟类疾病发展中起作用。已知[该菌]是人类中的一种新兴病原体，可被视为鸟类肺部以及潜在的皮肤或播散性感染的鉴别诊断。
