McPherson Andrew S, Haworth Sophie L, Kan Alex, de Miranda Luisa Monteiro, Krockenberger Mark B
Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, Sydney, NSW 2006, Australia.
J Fungi (Basel). 2025 Jan 15;11(1):64. doi: 10.3390/jof11010064.
Cryptococcosis is a fungal disease in humans and animals, caused by the and species complexes. Clinical cryptococcosis primarily manifests as upper respiratory tract disease; however, dissemination to other organs, particularly the brain, can occur. Nasal colonisation and subclinical cryptococcosis are common in koalas () due to their shared environmental niche with : trees. However, for reasons that remain unclear, the prevalence of clinical disease is low in koalas. Interactions between respiratory pathogens and the nasal mycobiome are thought to play a role in the development and progression of numerous respiratory diseases. As such, this study aimed to characterise the mycobiome of the nasal vestibule in koalas with and without evidence of cryptococcal colonisation and subclinical disease via the next-generation sequencing (NGS) of the ITS1 region of the fungal internal transcribed spacer (ITS) gene. Samples were collected from 47 koalas from a population of free-ranging koalas in the Liverpool Plains, NSW, Australia, with a known history of exposure and nasal colonisation. Of the 47 animals tested, 6.4% were culture-positive only, 4.3% were seropositive only, and 2.1% were culture- and seropositive. was detected in four samples via NGS. was not detected via NGS. There were no significant differences in the nasal mycobiomes of -positive and -negative animals; thus, we could not establish a definitive association between the mycobiome and infection outcomes. We identified a number of fungal genera that were significantly more abundant in samples from -positive animals, but there was no apparent relationship between these genera and the development of cryptococcosis. This study represents the first investigation of the nasal mycobiota of wild koalas. Further studies involving koalas with clinical disease are necessary to determine the role of the nasal mycobiota in the development of cryptococcosis.
隐球菌病是人和动物的一种真菌病，由新型隐球菌和格特隐球菌复合群引起。临床隐球菌病主要表现为上呼吸道疾病；然而，也可能扩散到其他器官，尤其是大脑。由于考拉与新生隐球菌共享环境生态位（桉树），鼻腔定植和亚临床隐球菌病在考拉中很常见。然而，原因尚不清楚，考拉临床疾病的患病率较低。呼吸道病原体与鼻腔真菌群落之间的相互作用被认为在多种呼吸道疾病的发生和发展中起作用。因此，本研究旨在通过对真菌内转录间隔区（ITS）基因的ITS1区域进行下一代测序（NGS），对有和没有隐球菌定植及亚临床疾病证据的考拉鼻前庭真菌群落进行特征分析。样本采集自澳大利亚新南威尔士州利物浦平原一群自由放养考拉中的47只，这些考拉有已知的新生隐球菌暴露和鼻腔定植史。在检测的47只动物中，仅培养阳性的占6.4%，仅血清学阳性的占4.3%，培养和血清学均阳性的占2.1%。通过NGS在4个样本中检测到新生隐球菌。通过NGS未检测到格特隐球菌。培养阳性和阴性动物的鼻腔真菌群落没有显著差异；因此，我们无法确定真菌群落与感染结果之间的明确关联。我们鉴定出一些在培养阳性动物样本中明显更丰富的真菌属，但这些属与隐球菌病的发生之间没有明显关系。本研究是对野生考拉鼻腔微生物群的首次调查。有必要对患有临床疾病的考拉进行进一步研究，以确定鼻腔微生物群在隐球菌病发生中的作用。
