title: Azole susceptibility of Malassezia pachydermatis and Malassezia furfur and tentative epidemiological cut-off values.
abstract: This study aims to determine the minimal inhibitory concentration (MIC) distribution and the epidemiological cut-off values (ECVs) of Malassezia pachydermatis and Malassezia furfur isolates for fluconazole (FLZ), itraconazole (ITZ), posaconazole (POS), and voriconazole (VOR). A total of 62 M. pachydermatis strains from dogs with dermatitis and 78 M. furfur strains from humans with bloodstream infections (BSI) were tested by a modified broth microdilution Clinical and Laboratory Standards Institute (CLSI) method. ITZ and POS displayed lower MICs than VOR and FLZ, regardless of the Malassezia species. The MIC data for azoles of M. pachydermatis were four two-fold dilutions lower than those of M. furfur. Based on the ECVs, about 94% of Malassezia strains might be categorized within susceptible population for all azoles, except for FLZ, and azole cross-resistance was detected in association with FLZ in M. pachydermatis but not in M. furfur.The study proposes, for the first time, tentative azole ECVs for M. pachydermatis and M. furfur for monitoring the emergence of isolates with decreased susceptibilities and shows that the azole MIC distribution varied according to the Malassezia species tested, thus suggesting the usefulness of determining the susceptibility profile for effective treatment of each species.
authors.affiliation: Dipartimento di Medicina Veterinaria, Università degli Studi di Bari "Aldo Moro", Italy claudia.cafarchia@uniba.it.
authors.forename: Claudia
authors.initials: C
authors.lastname: Cafarchia
authors.affiliation: Dipartimento di Medicina Veterinaria, Università degli Studi di Bari "Aldo Moro", Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Iatta
authors.affiliation: Dipartimento di Medicina Veterinaria, Università degli Studi di Bari "Aldo Moro", Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Immediato
authors.affiliation: Dipartimento di Medicina Veterinaria, Università degli Studi di Bari "Aldo Moro", Italy.
authors.forename: Maria Rita
authors.initials: MR
authors.lastname: Puttilli
authors.affiliation: Dipartimento di Medicina Veterinaria, Università degli Studi di Bari "Aldo Moro", Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Otranto
mesh_terms: D000818:Animals; D000935:Antifungal Agents / Q000494:pharmacology*; D001393:Azoles / Q000494:pharmacology*; D003881:Dermatomycoses / Q000382:microbiology / Q000662:veterinary*; D004283:Dog Diseases / Q000382:microbiology; D004285:Dogs; D016469:Fungemia / Q000382:microbiology*; D006801:Humans; D008290:Malassezia / Q000187:drug effects* / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests
chemical_list: D000935:Antifungal Agents; D001393:Azoles
keywords: Azole susceptibility; Malassezia furfur; Malassezia pachydermatis; bloodstream infections; epidemiological cut-off values; skin