Comparison of the Sensititre YeastOne ® and CLSI M38-A2 Microdilution Methods in Determining the Activity of Nine Antifungal Agents against Dermatophytes

Mycoses. 2021 Mar 24. doi: 10.1111/myc.13272. Online ahead of print.


BACKGROUND: Dermatophytes are the most common fungal pathogens causing superficial infections in humans with a high prevalence worldwide. The treatment of these infections is based on the use of topical and systemic antifungal agents. A convenient method with a high predictive value for testing the susceptibilities of dermatophytes is necessary.

OBJECTIVE: To evaluate the ability of the Sensititre YeastOne® in testing the activity of nine antifungal agents against dermatophytes.

METHODS: We compared Sensititre® with reference procedure for Anidulafungin (ANID), Micafungin sodium (MCF), Caspofungin Acetate (CAS), 5-Fluorocytosine (5FC), Posaconazole (PCZ), Voriconazole (VCZ), Itraconazole (ITZ), Fluconazole (FLZ) and Amphotericin B (AMB) against 79 dermatophyte isolates, the essential agreement (EA) and categorical agreement (CA) between the two methods were obtained.

RESULTS: The MICs or MECs obtained by the Sensititre® were usually lower than those obtained by the M38-A2. The overall EA between the two methods of nine antifungals was best for 5FC (100%), followed by MCF (94.9%), PCZ (84.8%), AMB (67.1%), FLZ (65.8%), VCZ (63.3%), ANID (29.1%), ITZ (20.3%) and CAS (2.5%). The overall CA between the two methods for all drugs was 100% except for ANID (97.4 %), MCF (95%) and PCZ (92.5%). Substantial discrepancies were observed with all drugs except for VCZ and 5FC. The results of M38-A2 in terms of GMIC (or GMEC) and MIC90 (or MEC90) were, in increasing order, as follows: MCF, PCZ, VCZ, ANID, ITZ, CAS, AMB, FLZ and 5FC.

CONCLUSIONS: The Sensititre YeastOne® shows poor EA with the reference method for dermatophytes, therefore M38-A2 should remain the reference procedure for antifungal susceptibility testing against dermatophytes.

PMID:33760301 | DOI:10.1111/myc.13272