Abstracts
Friday, January 2, 2026 at 01:00PM Submitted by Heather Sayles, Michigan State University
---
Title: Evaluation of anti-fungal resistance in confirmed cases of aspergillosis in penguins (Sphenisciformes) Authors: Heather Sayles1, Ronan Eustace1,3, Mayra Tsoi1,2, Rinosh Mani1.2 Affilitations: Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, Lansing MI Michigan State University Veterinary Diagnostic Laboratory, Lansing MI Potter Park Zoo, Lansing MI Abstract Aspergillosis is a life-threatening fungal infection caused by Aspergillus, a genus of molds that is commonly found in the environment. It is the leading cause of mortality in penguins held in captivity. Diagnosis of aspergillosis is challenging due to the difficulty of collecting antemortem samples. Presumptive cases are often diagnosed through a combination of clinical evaluation, diagnostic imaging, and laboratory testing. Long-term antifungal therapy is the cornerstone in the management of aspergillosis in penguins, but increased resistance to antifungals has been documented and could contribute to therapeutic failure. Specifically, mutations in the cyp51A gene have been implicated in azole resistance. Frozen samples of lung and air sacs tissue from confirmed cases of aspergillosis in penguins were evaluated. Fungal isolates were identified by colony morphology and MALDI-TOF mass spectrometry. Minimum inhibitory concentrations (MIC) were evaluated on all Aspergillus fumigatus isolates for voriconazole, itraconazole, amphotericin B, and terbinafine. Published MIC ranges were used to classify resistant isolates. Individual isolates were DNA sequenced and evaluated for b-tubulin (BenA), calmodulin (CaM), and the cyp51A genes, then compared to existing sequences in GenBank We anticipate finding a range of susceptibilities to different antifungal agents. Pan-azole resistance is of particular concern in strains of Aspergillus fumigatus. We expect these isolates may contain genetic mutations in genes encoding target enzymes such as cyp51A.
Determining the susceptibility of each isolate to the most commonly used antifungals will allow veterinarians to judiciously select the most effective drugs for the management of this condition, which can improve therapeutic outcomes and reduce risk of treatment failure or relapse.
