Post-antifungal effect of amphotericin B and voriconazole against germinated Aspergillus fumigatus conidia
2008 (English)In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, Vol. 61, no 6, 1309-11 p.Article in journal (Refereed) Published
OBJECTIVES: The post-antifungal effect (PAFE) of amphotericin B and voriconazole on germinated Aspergillus fumigatus conidia was studied using the BacT/Alert detection system based on fungal CO(2) production. METHODS: Germinated conidia of A. fumigatus were exposed to 1-10x MIC of amphotericin B for 1 and 4 h and to 2.5-40x MIC of voriconazole for 4 and 24 h. After removal of the drug by washing, similar numbers of exposed and control germlings were inoculated into Pedi-BacT culture bottles. CO(2) production was automatically monitored until the bottles signalled positive. The difference in time for positive signals in drug-exposed and control bottles was used to calculate the PAFE. RESULTS: The killing rate of amphotericin B against germlings was both concentration- and time-dependent, as has been previously found for actively growing hyphae. Similarly, voriconazole showed fungicidal effect after 24 h of exposure, but not after 4 h. Amphotericin B induced a long concentration- and time-dependent PAFE, whereas voriconazole resulted in a short and dose-independent PAFE that was significantly longer after 24 h than after 4 h of exposure. CONCLUSIONS: An automated method is presented for the determination of PAFE on filamentous fungi using quantifiable numbers of germinated conidia. In contrast to previous results obtained from conidia, this method could demonstrate a PAFE of amphotericin B on Aspergillus that shared characteristics similar to that on Candida spp.
Place, publisher, year, edition, pages
2008. Vol. 61, no 6, 1309-11 p.
azoles, filamentous fungi, polyenes
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:uu:diva-88553DOI: 10.1093/jac/dkn129ISI: 000256172900020PubMedID: 18367461OAI: oai:DiVA.org:uu-88553DiVA: diva2:158566