Warnell School of Forestry and Natural Resources, 180 E. Green St., University of Georgia, Athens, Georgia 30602, USA.
Southeastern Cooperative Wildlife Disease Study, 589 D.W. Brooks Dr., College of Veterinary Medicine, University of Georgia, Athens, Georgia 30602, USA.
J Wildl Dis. 2023 Oct 1;59(4):759-766. doi: 10.7589/JWD-D-22-00141.
Twenty-four American white ibis (Eudocimus albus) nestlings were collected in Florida (USA) on 17 April 2017 to establish a captive flock. On 7 May 2017, three birds died suddenly, following severe lethargy, hemorrhaging from the mouth and nares, anorexia, and production of bright-green colored feces. An additional ibis with delayed growth and pathological fractures was euthanized 18 May 2017. Severe ventriculitis associated with Macrorhabdus ornithogaster was noted in all four birds, bacterial sepsis was confirmed in one bird by culture and histologic examination, and bacterial endotoxemia was suspected in two birds based on gross and histologic examination, but no bacteria were isolated from these birds. Birds also had vitamin E liver levels consistent with coagulopathy previously described in pelicans. We sampled feces from 91 adult, free-living, healthy ibis in Florida in July 2017 and found 71% were shedding organisms with morphologic characteristics consistent with Macrorhabdus sp. Molecular characterization of the ibis-origin M. ornithogaster showed it was phylogenetically related to numerous M. ornithogaster sequences. It is unknown if M. ornithogaster infection resulted in clinical disease as a result of dietary or stress-related dysbiosis, or other factors. Macrorhabdus-associated disease has not previously been confirmed in wading birds. We discuss potential associations of gastric M. ornithogaster infection with morbidity and mortality in these cases and highlight the need for additional studies on this pathogen in free-living birds.
2017 年 4 月 17 日，在佛罗里达州（美国）收集了 24 只美洲白鹈鹕雏鸟，以建立一个圈养种群。2017 年 5 月 7 日，三只雏鸟突然死亡，此前出现严重嗜睡、口鼻出血、食欲不振和产生亮绿色粪便的症状。另外一只生长迟缓并有病理性骨折的雏鸟于 2017 年 5 月 18 日被安乐死。四只鸟均出现与 Macrorhabdus ornithogaster 相关的严重脑膜炎，一只鸟通过培养和组织学检查证实有细菌败血症，两只鸟根据大体和组织学检查怀疑有细菌内毒素血症，但这些鸟未分离出细菌。这些鸟还具有与 previously described in pelicans 一致的维生素 E 肝水平，提示有凝血功能障碍。我们于 2017 年 7 月从佛罗里达州的 91 只自由生活的健康白鹈鹕中采集粪便样本，发现 71%的粪便中存在形态特征与 Macrorhabdus sp. 一致的微生物。对白鹈鹕来源的 M. ornithogaster 的分子特征表明，它与许多 M. ornithogaster 序列在系统发育上相关。尚不清楚 M. ornithogaster 感染是否因饮食或应激相关的菌群失调或其他因素导致临床疾病。以前尚未在涉水鸟类中确认 Macrorhabdus 相关疾病。我们讨论了胃 M. ornithogaster 感染与这些病例的发病率和死亡率的潜在关联，并强调需要对自由生活鸟类中的这种病原体进行更多研究。
