Determination of Minimum Inhibitory Concentrations of Several Azole Antifungals for <i>Malassezia furfur</i>

Ahn, Kyu Joon; Ashbee, H. Ruth

doi:10.5021/ad.1996.8.3.187

Cited by 6 publications

(5 citation statements)

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“…Although the experimental modifications used for susceptibility testing in this study were in agreement with those described by other authors, comparison of data was difficult due to the recent expansion of the genus in new species by PCR methods . Results from previous studies which did not employ molecular methods may correspond to false identification of the species.…”

Section: Resultssupporting

confidence: 68%

“…To study the in vitro Malassezia species susceptibility to certain antifungals, different diffusion and dilution methods with a variation in the culture media composition have been tried with the purpose to enable the growth of these lipo‐dependant yeasts . Different MICs values had been shown using the same clinical isolates with different experimental variables …”

Section: Resultsmentioning

confidence: 99%

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In vitro antifungal activity of topical and systemic antifungal drugs against Malassezia species

Carrillo-Muñoz¹,

Rojas

Tur-Tur

et al. 2013

Mycoses

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The strict nutritional requirements of Malassezia species make it difficult to test the antifungal susceptibility. Treatments of the chronic and recurrent infections associated with Malassezia spp. are usually ineffective. The objective of this study was to obtain in vitro susceptibility profile of 76 clinical isolates of Malassezia species against 16 antifungal drugs used for topical or systemic treatment. Isolates were identified by restriction fragment length polymorphism. Minimal inhibitory concentrations (MIC) were obtained by a modified microdilution method based on the Clinical Laboratory Standards Institute reference document M27-A3. The modifications allowed a good growth of all tested species. High in vitro antifungal activity of most tested drugs was observed, especially triazole derivatives, except for fluconazole which presented the highest MICs and widest range of concentrations. Ketoconazole and itraconazole demonstrated a great activity. Higher MICs values were obtained with Malassezia furfur indicating a low susceptibility to most of the antifungal agents tested. Malassezia sympodialis and Malassezia pachydermatis were found to be more-susceptible species than M. furfur, Malassezia globosa, Malassezia slooffiae and Malassezia restricta. Topical substances were also active but provide higher MICs than the compounds for systemic use. The differences observed in the antifungals activity and interspecies variability demonstrated the importance to studying the susceptibility profile of each species to obtain reliable information for defining an effective treatment regimen.

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Section: Resultssupporting

confidence: 68%

Section: Resultsmentioning

confidence: 99%

In vitro antifungal activity of topical and systemic antifungal drugs against Malassezia species

Carrillo-Muñoz¹,

Rojas

Tur-Tur

et al. 2013

Mycoses

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“…MICs of ITC for Malassezia species ranged from Յ0.03 to 0.06 g/ml. Ahn et al (1) obtained MICs of ITC for M. furfur strains between 0.015 and 0.06 g/ml; these values were lower than those reported by Faergemann (MICs, 0.1 to 0.2 g/ml) (8). Strippoli et al (26) studied the in vitro activity of several antifungal agents (KTC, miconazole, econazole, fenticonazole, ITC, and FLC) against M. furfur isolates from pityriasis versicolor lesions and observed that ITC and KTC were the most active drugs, with a MIC of 0.8 g/ml for both.…”

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confidence: 42%

In Vitro Susceptibilities ofMalasseziaSpecies to a New Triazole, Albaconazole (UR-9825), and Other Antifungal Compounds

Garau

Pereiro

Palacio

2003

Antimicrob Agents Chemother

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The in vitro activity of the new triazole albaconazole (UR-9825) in comparison with those of flucytosine, fluconazole, ketoconazole, itraconazole, and voriconazole against 70 strains of Malassezia spp. was determined by a microdilution method using a colorimetric indicator for metabolic activity. Albaconazole showed an in vitro profile similar to those of the different antifungals tested (MIC < 0.06 g/ml for all the strains).Yeasts of the genus Malassezia are part of the normal mycota of the skin of humans and other warm-blooded animals, particularly in areas rich in sebaceous glands (19). Malassezia species may also be etiological agents of skin disorders and, uncommonly, systemic infections (3, 6, 16, 24, 30).In 1997, the National Committee for Clinical Laboratory Standards approved a broth micro-and macrodilution method for susceptibility testing of yeasts with RPMI 1640 medium (NCCLS-M27A) (21). However, this document is not applicable to Malassezia species other than Malassezia pachydermatis, because these organisms do not grow without lipidic substances in the medium. Only a few systems for in vitro susceptibility testing of Malassezia species have been described. In addition to present measurements in solid media, several microdilution methods have been used, but the different liquid media used, such as modified Dixon (19,27) and LeemingNotman (15), are turbid; consequently, the visual and turbidimetric results are difficult to interpret. A liquid medium method has been observed to overcome the difficulties in growth reading if one uses a colorimetric indicator for metabolic activity (Alamar blue) (25). Recently, Nakamura et al. (20) described a new microdilution method based on the urease activity of Malassezia spp.Albaconazole (ABC) is a new systemic triazole under development by J. Uriach & Cia S.A. (Barcelona, Spain) with both potent and broad-spectrum antifungal activity, good pharmacokinetics, and excellent bioavailability. It has demonstrated good in vitro activities against pathogenic yeasts (23), dermatophytes (10), and some filamentous fungi (4), including Scedosporium prolificans (5). It has also been shown to be active in the treatment of systemic aspergillosis and candidiasis in experimental animal models (2).The aim of this study was to compare the in vitro activity of ABC with those of five antifungal drugs, namely, flucytosine (5FC), fluconazole (FLC), ketoconazole (KTC), itraconazole (ITC), and voriconazole (VRC), against 70 isolates of Malassezia, namely, M. furfur (n ϭ 24), M. pachydermatis (n ϭ 10), M. sympodialis (n ϭ 21), and M. slooffiae (n ϭ 15). M. furfur was obtained from human skin, that of neonates with long stays in intensive care units. M. pachydermatis and M. slooffiae were obtained from healthy and diseased ears of dogs and pigs, respectively. M. sympodialis was isolated from normal human skin. Susceptibility testing of the drugs was initially performed with M. restricta (n ϭ 1), M. obtusa (n ϭ 1), and M. globosa (n ϭ 24). However, we were unable to obtain MICs due to the ...

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“…Earlier data were for either M. furfur or Pityrosporum spp. (1,6,7,14,18,19). Susceptibility to the three azoles was species dependent, with low MICs (Ͻ1 g/ml) for most Malassezia spp.…”

Section: Pachydermatis)mentioning

confidence: 99%

A Modified Christensen's Urea and CLSI Broth Microdilution Method for Testing Susceptibilities of SixMalasseziaSpecies to Voriconazole, Itraconazole, and Ketoconazole

2006

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Two supplemented broths (Christensen's urea with 0.1% Tween 80 and 0.5% Tween 40 and RPMI 1640 with 1% glycerol, 1% peptone, 1.8% glucose, and 0.05% Tween 80) were evaluated to determine voriconazole, itraconazole, and ketoconazole MICs for 200 Malassezia sp. isolates. Malassezia globosa and M. restricta were the least susceptible species (MICs at which 90% of the isolates tested were inhibited, 1 to >8 g/ml versus 0.25 to 1 g/ml).An increased incidence of severe dermatological and systemic infections by Malassezia spp. has been reported among immunosuppressed patients. Standardized assays are not available to determine the in vitro susceptibilities of these yeasts to any antifungal due to their complex nutritional requirements. Recently, Christensen's urea (measures metabolic activity) and supplemented RPMI 1640 (measures growth inhibition) broths were evaluated (16,21 pachydermatis).The 200 isolates were cultured from 77 patients (human immunodeficiency virus positive and negative) with dermatological pathologies (3) and 33 healthy volunteers. Isolates were identified by following conventional standard guidelines (10,11,15). Six reference Malassezia strains (see Table 2), CLSI quality control strain Candida krusei ATCC 6258 (2, 17), and Cryptococcus neoformans ATCC 90112 were tested as controls. The identification of representative isolates of each species and of the six reference isolates was confirmed by PCR-restriction fragment length polymorphism (8). For the quality control strain, the MICs of the three azoles were within the expected ranges (2, 17).CLSI RPMI 1640 medium (17)

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Determination of Minimum Inhibitory Concentrations of Several Azole Antifungals for Malassezia furfur

Cited by 6 publications

References 0 publications

In vitro antifungal activity of topical and systemic antifungal drugs against Malassezia species

In vitro antifungal activity of topical and systemic antifungal drugs against Malassezia species

In Vitro Susceptibilities ofMalasseziaSpecies to a New Triazole, Albaconazole (UR-9825), and Other Antifungal Compounds

A Modified Christensen's Urea and CLSI Broth Microdilution Method for Testing Susceptibilities of SixMalasseziaSpecies to Voriconazole, Itraconazole, and Ketoconazole

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