20.500.12556/RUL-182323 Rapid MALDI-TOF mass spectrometry identification of the chalkbrood pathogen Ascosphaera apis Ascosphaera apis is a fungal pathogen of honeybee larvae and the primary cause of chalkbrood disease, which weakens bee colonies, impairing their ability to function effectively and making them more susceptible to other pathogens and environmental stressors. This study aimed to develop and validate an in-house matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) spectral library for A. apis. A new MALDI-TOF MS library was constructed using reference Ascosphaera species and validated through whole-genome-based confirmation of 31 clinical isolates of A. apis. Three different protein extraction methods were tested and compared: liquid cultivation, formic acid–ethanol extraction and extended direct transfer. Our findings demonstrate that MALDI-TOF MS is a rapid and reliable tool for identifying A. apis under the tested laboratory conditions and within the analyzed strain set, with no misidentifications observed for the liquid cultivation and formic acid–ethanol extraction methods. The extended direct mycelium transfer method was slightly less effective but still showed a high sensitivity of 83.9%. This study provides a foundation for improving diagnostic approaches in the management of honeybee fungal diseases. Ascosphaera apis matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS species identification whole-genome sequencing (WGS) honeybee fungal diseases true false true Angleški jezik Angleški jezik Članek v reviji 2026-05-07 09:17:07 2026-05-07 09:17:12 2026-05-08 04:51:46 0000-00-00 00:00:00 2026 0 0 12 str. Issue 5, art. 311 Vol. 12 2026 0000-00-00 Zaloznikova Objavljeno apc 0000-00-00 0000-00-00 2026-01-01 638:616 2309-608X 10.3390/jof12050311 276949507 Rapid-Zdovc.pdf Rapid-Zdovc.pdf 1 2D7047F46A339A08B182B72D0F70C7A5 44373c560ff476e1d75d9473e73e54acda30ffceafde7b2b6470062b2ecd8222 2ee5677a-49e8-11f1-b0ab-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=233476 https://www.mdpi.com/2309-608X/12/5/311 Odprti dostop 1 7a3d4316-49e4-11f1-b0ab-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=233475 Veterinarska fakulteta Biotehniška fakulteta 0 0 0