Pathogenicity of Aspergillus nidulans isolated from the liver of diseased goat (Capra hircus)

Aspergillus nidulans, an environmentally ubiquitous opportunistic pathogen, can induce invasive aspergillosis in humans and animals, with numerous human infection cases documented. Here, we isolated A. nidulans strain XM06 from the liver of a diseased goat with suspected fungal infection. XM06 formed dark‑green colonies with white fluffy margins and a powdery center on PDA, and PCR amplification yielded products corresponding to putative homologous virulence genes, including Cat1, Alp2, and Aspf1. Using a mouse infection model, we characterized its pathogenic potential. The infected mice exhibited reduced body weight and average daily feed intake (P < 0.05), with morbidity and mortality rates of 66.7% and 33.3%, respectively. In infected animals, the organ indices of the liver, spleen, lung, kidney and brain were elevated, while the intestinal index was reduced (P < 0.01). No intergroup difference was observed for the heart index (P > 0.05). Fungal burdens were highest in the spleen and liver (P < 0.05). Histopathological lesions including congestion, necrosis and inflammatory infiltration were observed in multiple organs. Antifungal assays revealed small inhibition‑zone diameters for amphotericin B and comparatively larger inhibition zones for itraconazole, caspofungin and voriconazole against strain XM06. This work provides preliminary pathological and in vitro drug-response data for goat-derived A. nidulans, offering baseline information for studying animal invasive aspergillosis. Notably, our mouse infection assay only demonstrates the pathogenic potential of XM06 and cannot confirm that this isolate caused the original disease outbreak in goats.