The polyene antimycotics nystatin and filipin disrupt the plasma membrane, whereas natamycin inhibits endocytosis in germinating conidia of Penicillium discolor.
OBJECTIVE
To investigate the differences in membrane permeability and the effect on endocytosis of the polyene antimycotics nystatin, filipin and natamycin on germinating fungal conidia.


RESULTS
The model system was Penicillium discolor, a food spoilage fungus. Filipin resulted in permeabilization of germinating conidia for the fluorescent probes TOTO-1 and FM4-64, but not for ferricyanide ions. Nystatin caused influx of all these compounds while natamycin did not. Untreated germinating conidia internalize the endocytic marker FM4-64. Pretreatment of germinating conidia with natamycin showed a dose and time dependent inhibition of endocytosis as judged by the lack of formation of early endosomal compartments.


CONCLUSIONS
The results obtained from this study indicated that, unlike nystatin and filipin, natamycin is unable to permeabilize germinating conidia, but interferes with endocytosis in a dose and time dependent manner.


CONCLUSIONS
Natamycin acts via a different mode of action than other polyene antimycotics. These results offer useful information for new strategies to prevent fungal spoilage on food products and infection on agricultural crops. For laboratory use, natamycin can be used as a specific inhibitor of early endocytosis in fungal cells.
Van Leeuwen
M R
MR
Applied and Industrial Mycology, CBS/Fungal Biodiversity Centre, Utrecht, The Netherlands.
Golovina
E A
EA
Dijksterhuis
J
J
D000935:Antifungal Agents / Q000494:pharmacology*; D002462:Cell Membrane / Q000378:metabolism*; D002463:Cell Membrane Permeability / Q000187:drug effects; D004705:Endocytosis / Q000187:drug effects*; D005372:Filipin / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D010866:Natamycin / Q000494:pharmacology; D009761:Nystatin / Q000494:pharmacology; D010407:Penicillium / Q000254:growth & development / Q000378:metabolism*; D046590:Spectroscopy, Electron Energy-Loss; D013172:Spores, Fungal / Q000187:drug effects* / Q000254:growth & development
D000935:Antifungal Agents; D009761:Nystatin; D005372:Filipin; D010866:Natamycin