Dermatophytes can invade the stratum corneum of the skin and other keratinized tissues and are responsible for a broad diversity of diseases of skin, nails and hair. Although the standard identification of dermatophytoses depends on macroscopic and microscopic characterization of the colonies grown on special media, there are a number of limitations owing to intraspecies morphological variability, atypical morphology or interspecies morphological similarity which entails improvement in the identification methods. Matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a novel method which proved to be effective for rapid and reliable identification of dermatophytes grown in cultures when compared to conventional methods. We evaluated the performance of Bruker MALDI-TOF MS System (Bruker Daltonics, Germany) for identification of clinically relevant dermatophytes. In order to increase the identification capacity of the system, we created supplemental spectral database entries using ten reference dermatophyte strains (ten species in two genera). The utility of the generated database was then challenged using a total of 126 dermatophytes (115 clinical isolates and 11 additional reference strains). The results were evaluated by both manufacturer-recommended and lowered cutoff scores. MALDI-TOF MS provided correct identification in 122 (96.8 %) and 113 (89.7 %) of the isolates with the lowered scores and using the supplemented database, respectively, versus 65 (51.6 %) and 17 (13.5 %) correct identifications obtained by the unmodified database and recommended scores at the genus and species levels, respectively. Our results support the potential utility of MALDI-TOF MS as a routine tool for accurate and reliable identification of dermatophytes.

PACK-CXL appears as a promising treatment option for difficult-to-treat cases of fungal keratitis and 0.25% riboflavin concentration increases fungicidal effect of the procedure dramatically.

The Clinical and Laboratory Standards Institute (CLSI) Subcommittee on Antifungal Susceptibility Testing has newly introduced species-specific clinical breakpoints (CBPs) for fluconazole and voriconazole. When CBPs can not be determined, wild-type minimal inhibitory concentration (MIC) distributions are detected and epidemiological cutoff values (ECVs) provide valuable means for the detection of emerging resistance. The aim of this study is to determine triazole resistance patterns in Candida species by the recently revised CLSI CBPs. A total of 140 Candida strains isolated from blood cultures of patients with invasive candidiasis hospitalized in various intensive care units in Turkey and sent to our reference laboratory between 2011-2012, were included in the study. The isolates were identified by conventional methods, and susceptibility testing was performed against fluconazole, itraconazole and voriconazole, by the 24-h CLSI broth microdilution (BMD) method. Azole resistance rates for all Candida species were determined using the new species-specific CLSI CBPs and ECVs criteria, when appropriate. The species distribution of the isolates were as follows; C.parapsilosis (n= 31 ), C.tropicalis (n= 26 ), C.glabrata (n= 21), C.albicans (n= 18), C.lusitaniae (n= 16), C.krusei (n= 16), C.kefyr (n= 9), C.guilliermondii (n= 2), and C.dubliniensis (n= 1). According to the newly determined CLSI CBPs for fluconazole and C.albicans, C.parapsilosis, C.tropicalis [susceptible (S), ≤ 2 µg/ml; dose-dependent susceptible (SDD), 4 µg/ml; resistant (R), ≥ 8 µg/ml], and C.glabrata (SDD, ≤ 32 µg/ml; R≥ 64 µg/ml) and for voriconazole and C.albicans, C.parapsilosis, C.tropicalis (S, ≤ 0.12 µg/ml; SDD, 0.25-0.5 µg/ml; R, ≥ 1 µg/ml), and C.krusei (S, ≤ 0.5 µg/ml; SDD, 1 µg/ml; R, ≥ 2 µg/ml), it was found that three of C.albicans, one of C.parapsilosis and one of C.glabrata isolates were resistant to fluconazole, while two of C.albicans and two of C.tropicalis were resistant to voriconazole. The ECVs of 0.5 µg/ml for voriconazole and C.glabrata were used to differentiate wild-type (MIC ≤ ECV) from non-wild-type (MIC > ECV) strains. Five of C.glabrata were non-WT for voriconazole. Due to the lack of CBPs for the less common species, the ECVs for fluconazole, itraconazole and voriconazole, respectively, were used for C.lusitaniae (2 µg/ml, 0.5 µg/ml, 0.03 µg/ml), C.guilliermondii (8 µg/ml, 1 µg/ml, 0.25 µg/ml), C.dubliniensis (0.5 µg/ml, 0.25 µg/ml, 0.03 µg/ml), and C.kefyr (1 µg/ml, 0.015 µg/ml) to categorize isolates of these species as wild- and non-wild-type. When the ECVs were used for fluconazole, one each of C.lusitaniae, C.dubliniensis and C.kefyr; for voriconazole, three of C.lusitaniae and one of C.kefyr were detected as non-wild-type. Overall, a total of five Candida species were resistant to fluconazole and four to voriconazole and among these species one each of C.parapsilosis, C.tropicalis, C.glabrata, C.lusitaniae, C.kefyr and three of C.albicans exhibited cross-resistance at least against two azoles. It was concluded that,...

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