Comparison of the Sensititre YeastOne^® and CLSI M38‐A2 microdilution methods in determining the activity of nine antifungal agents against dermatophytes

Abstract

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.

Antifungal activity of compounds from Gordonia sp. WA8-44 isolated from the gut of Periplaneta americana and molecular docking studies

“…Following the Clinical and Laboratory Standards Institute (CLSI) guidelines, the M27-A3 method was used to determine the minimum inhibitory concentrations (MICs) of C. albicans [ 23 ], while the M38-A2 method was used for filamentous fungi [ 24 ]. To prepare the samples, C. albicans was diluted with RPMI1640 to a final concentration of 0.5–2.5 × 10 3 spores/ml, A. fumigatus , and A. niger were diluted to 1 × 10 4 spores/ml, and T. rubrum was diluted to 2 × 10 3 spores/ml.…”