Volume: 5, 2026
5th International PhD Students’ Conference at the University of Life Sciences in Lublin, Poland:
ENVIRONMENT – PLANT – ANIMAL – PRODUCT
Abstract number: A024
DOI: https://doi.org/10.24326/ICDSUPL5.A024
Published online: 22 April 2026
In vitro activity of compounds with antifungal potential against Malassezia pachydermatis strains
Dominik Łagowski*1, Kacper Wykrętowicz2, Anna Krawczak2 and Ewelina Czyżewska-Dros3
1 Department of Preclinical Sciences and Infectious Diseases, Faculty of Veterinary Medicine and Animal Science, Poznan University of Life Sciences, 35 Wołyńska St., 60-637 Poznań, Poland
2 Student Research Club of Veterinary Medicine Students, Veterinary Microbiology Section, Faculty of Veterinary Medicine and Animal Sciences, Poznań University of Life Sciences, 35 Wołyńska St., 60-637 Poznań, Poland
3 Department of Internal Diseases and Diagnostics, Faculty of Veterinary Medicine and Animal Science, Poznan University of Life Sciences, 50 Szydłowska St., 60-637 Poznań, Poland
* Corresponding author: dominik.lagowski@up.poznan.pl
The in vitro susceptibility of 104 Malassezia pachydermatis isolates collected from dogs with otitis externa was assessed against capsaicin, acetylsalicylic acid, ebselen, diphenyl diselenide, polymyxin B and milbemycin oxime. Before determining the MIC (Minimum Inhibitory Concentration), all strains were streaked onto Sabouraud agar enriched with 1% Tween 80 and 0.005% chloramphenicol, and then incubated for 72 hours at 35 °C. The test was performed using the microdilution method. Two-fold dilutions of the test substances in Sabouraud broth supplemented with 1% Tween 80 were dispensed into 96-well microplates. Each well, except the negative control containing only medium, was then inoculated with 100 µL of the inoculum, resulting in a final suspension at approximately 10⁴ CFU/mL. The strains Candida parapsilosis ATCC 22019 and Pichia kudriavzevii ATCC 6258 were used as quality controls. Visual reading was performed after 72 h of incubation at 32 °C, and the MIC endpoint was determined as the lowest concentration resulting in a more than 90% reduction in turbidity compared to the growth control. The test was performed three times. The MIC50 and MIC90 values were defined as the concentrations inhibiting growth in 50% and 90% of the tested strains, respectively. For polymyxin B, the MIC50 and MIC90 values were 4 and 256, respectively; for ebselen, 128 and 256; for diphenyl diselenide, 64 and 256; for milbemycin oxime, 256 and 256; for acetylsalicylic acid, 256 and 256; and for capsaicin, 256 and 256. The lowest MIC50 value was recorded for polymyxin B, whereas, for all substances tested, the MIC90 was 256.
The source of funding: The work was supported by the National Science Centre, Poland, no MINIATURA 2024/08/X/NZ5/00356.
Keywords: acetylsalicylic acid; capsaicin; ebselen; Malassezia pachydermatis; polymyxin B
How to cite
Łagowski D., Wykrętowicz K., Krawczak A., Czyżewska-Dros E., 2026. In vitro activity of compounds with antifungal potential against Malassezia pachydermatis strains. In: 5th International PhD Students’ Conference at the University of Life Sciences in Lublin, Poland: Environment – Plant – Animal – Product. https://doi.org/10.24326/ICDSUPL5.A024