In Vitro Susceptibility Testing of Aspergillus and Non-Aspergillus Filamentous Moulds to Antifungal Agents: Evaluation of Three Different Methods

Gordana Mirchevska¹, Philipp P. Bosshard²

¹Institute of Microbiology and Parasitology, Faculty of Medicine, University “Ss Cyril and Methodius”, Skopje, Republic of Macedonia; ²Department of Dermatology, University Hospital Zurich, Zurich, Switzerland
 

Aim: The aim of this study was to evaluate the suitability of Sensititre YeastOne (SYO) method for susceptibility profiles’ determination of non-Aspergillus moulds and of E-test for Aspergillus spp. and non-Aspergillus moulds, in comparison with the M38-A reference broth microdilution (BMD) method.

Material and Methods: A total of 33 clinical isolates of filamentous fungi were tested.

Results: The agreement between E-test and BMD at ± 2 dilutions was 82.4%, 83.3% and 82.4% for amphotericin B, itraconazole and voriconazole, respectively. The agreement between SYO and BMD at ± 2 dilutions was 76.5%, 66.7% and 88.2% for amphotericin B, itraconazole and voriconazole, respectively. The majority of differing results are due to higher MICs with the reference method. In particular, SYO was unable to detect some of the potentially amphotericin B resistant strains. We found that both E-test and SYO method were reproducible and served as suitable methods for antifungal susceptibility testing of moulds.

Conclusion: In conclusion, both E-test and SYO method are promising, but require further investigation to identify the optimum conditions for their use in testing of susceptibility profiles of filamentous fungi to antifungal agents.

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Citation: Mirchevska G, Bosshard PP. In Vitro Susceptibility Testing of Aspergillus and Non-Aspergillus Filamentous Moulds to Antifungal Agents: Evaluation of Three Different Methods. Maced J Med Sci. 2012 Oct 15; 5(3):280-287. http://dx.doi.org/10.3889/MJMS.1857-5773.2012.0257.
Key words: Aspergillus; filamentous fungi; antifungals; resistance; susceptibility testing.
Correspondence: Dr. Gordana Mirchevska. Institute of Microbiology and Parasitology, Faculty of Medicine, University “Ss Cyril and Methodius”, 50. Divizija No 16, 1109 Skopje, Republic of Macedonia. E-mail: gordmir@yahoo.com
Received: 03-Jul-2011; Revised: 19-Sep-2011; Accepted: 20-Oct-2011; Online first: 23-Sep-2012
Copyright: © 2012 Mirchevska G. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Competing Interests: The authors have declared that no competing interests exist.
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