Dermatophyte susceptibilities to antifungal azole agents tested in vitro by broth macro and microdilution methods

Siqueira, Emerson Roberto; Ferreira, Joseane Cristina; Pedroso, Reginaldo dos Santos; Lavrador, Marco Aurélio Sicchiroli; Candido, Renato

doi:10.1590/s0036-46652008000100001

Cited by 16 publications

(16 citation statements)

References 22 publications

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“…Thus, it was necessary to compare the results found in this study with results of collaborative studies reported in the literature, using the same method. MIC values for ITC (0.0019‐0.25 μg/mL) and VRC (0.0019‐0.125 μg/mL) observed in this study were lower than the MIC values found in studies conducted in Brazil and in India . In those studies, Siqueira et al and Araújo et al reported low MIC values for azole derivatives against all tested species .…”

Section: Discussioncontrasting

confidence: 77%

In vitro activity of azole derivatives and griseofulvin against planktonic and biofilm growth of clinical isolates of dermatophytes

Brilhante

Correia

Guedes

et al. 2018

Mycoses

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As shown by recent research, most of the clinically relevant fungi, including dermatophytes, form biofilms in vitro and in vivo, which may exhibit antimicrobial tolerance that favour recurrent infections. The aim of this study was to determine the minimum inhibitory concentrations (MICs) of itraconazole (ITC), voriconazole (VCZ) and griseofulvin (GRI) against Trichophyton rubrum, Trichophyton tonsurans, Trichophyton mentagrophytes, Microsporum canis and Microsporum gypseum in planktonic and biofilm growth. For the planktonic form, susceptibility testing was performed according to the Clinical and Laboratory Standards Institute (CLSI), document M38-A2, while biofilm susceptibility was evaluated using the XTT colorimetric essay. The planktonic growth of all strains was inhibited, with MIC values ranging from 0.00195 to 0.1225 μg/mL for VRC, 0.00195 to 0.25 μg/mL for ITC and <0.0039 to 4 μg/mL for GRI, while a 50-fold increase in the MIC was required to significantly reduce the metabolic activity (P < .05) of dermatophyte biofilms. In brief, the ability of dermatophytes to form biofilms may be a contributing factor for the recalcitrance of dermatophytoses or the dissemination of the disease.

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Section: Discussioncontrasting

confidence: 77%

In vitro activity of azole derivatives and griseofulvin against planktonic and biofilm growth of clinical isolates of dermatophytes

Brilhante

Correia

Guedes

et al. 2018

Mycoses

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“…Since drugs were tested for their potential as topical treatments, microtitre plates were incubated at the physiologically relevant temperature of 30°C (while the average skin temperature is affected by clothes coverage, location, air temperature, or patient age, the mean temperature of uncovered human skin at room temperature (23–25°C) is 31.5°C, with foot temperature (site of onychomycosis) even lower [34], [35], [36]). 30°C is also the temperature recommended by American Type Culture Collection for the growth of both C. albicans SC5314 and T. rubrum ATCC MYA-4438 (www.atcc.org), and commonly for these species in antifungal susceptibility studies, (for example [37], [38], [39], [40], [41], [42]). Following incubation, the optical density at wavelength 600 nm (OD 600 ) was read using a Tecan Sunrise plate absorbance reader.…”

Section: Methodsmentioning

confidence: 99%

Calcofluor White Combination Antifungal Treatments for Trichophyton rubrum and Candida albicans

2012

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Superficial mycoses caused by dermatophyte fungi are among the most common infections worldwide, yet treatment is restricted by limited effective drugs available, drug toxicity, and emergence of drug resistance. The stilbene fluorescent brightener calcofluor white (CFW) inhibits fungi by binding chitin in the cell wall, disrupting cell wall integrity, and thus entails a different mechanism of inhibition than currently available antifungal drugs. To identify novel therapeutic options for the treatment of skin infections, we compared the sensitivity of representative strains of the dermatophyte Trichophyton rubrum and Candida albicans to CFW and a panel of fluorescent brighteners and phytoalexin compounds. We identified the structurally related stilbene fluorescent brighteners 71, 85, 113 and 134 as fungicidal to both T. rubrum and C. albicans to a similar degree as CFW, and the stilbene phytoalexins pinosylvan monomethyl ether and pterostilbene inhibited to a lesser degree, allowing us to develop a structure-activity relationship for fungal inhibition. Given the abilities of CFW to absorb UV 365 nm and bind specifically to fungal cell walls, we tested whether CFW combined with UV 365 nm irradiation would be synergistic to fungi and provide a novel photodynamic treatment option. However, while both treatments individually were cytocidal, UV 365 nm irradiation reduced sensitivity to CFW, which we attribute to CFW photoinactivation. We also tested combination treatments of CFW with other fungal inhibitors and identified synergistic interactions between CFW and some ergosterol biosynthesis inhibitors in C. albicans . Therefore, our studies identify novel fungal inhibitors and drug interactions, offering promise for combination topical treatment regimes for superficial mycoses.

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“…However, these methods are time-consuming and labour-intensive, and are not practical for the clinical laboratory. Therefore, simple alternative approaches are needed [1,3,4,[6][7][8].…”

Section: Introductionmentioning

confidence: 99%

Investigation of In Vitro Activity of Five Antifungal Drugs against Dermatophytes Species Isolated from Clinical Samples Using the E-Test Method

Aktaş

Yiğit

Aktaş

et al. 2014

EAJM

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Objective: Dermatomycosis is an infection with fungi related to the skin: glabrous skin, hair and/or nails. Oral treatment of fungal infections in dermatology has become a preferred modality for the management of these very common conditions. Although there are increasing numbers of antifungals available for treatment of dermatophytes, some cases and relapses have been unresponsive to treatment. The determination of fungus in-vitro antifungal susceptibility has been reported to be important for the ability to eradicate dermatophytes. It is necessary to perform antifungal susceptibility testing of dermatophytes. E-test (AB Biodisk, Sweden) is a rapid, easy-toperform in-vitro antifungal susceptibility test. The aim of this study was to investigate the susceptibility of the different species of dermatophyte strains isolated clinical specimens to five antifungal agents using the E-test method. Materials and Methods:A total of 66 specimens were collected from the nails, feet, inguinal region, trunk and hands. These strains tested MIC endpoints of E-test for amphotericin B, fluconazole, itraconazole, caspofungin, and ketoconazole were read after 72, and 96 hours incubation for each strain on RPMI 1640 agar. Results:The dermatophytes tested included Trichophyton rubrum 43 (65.1%), Trichophyton mentagrophytes 7 (10.7%), Microsporum canis 5 (7.6%), Trichophyton tonsurans 5 (7.6%), Epidermophyton floccosum 4 (6.0%) and Trichophyton violaceum 2 (3.0%). The most active agent against all dermatophytes species was caspofungin with a minimal inhibitory concentration (MIC) range (μg/mL ) (0, 19-48, 2-256, 2-8, 256, 256, 8-24).Conclusion: E-test seems to be an alternative method to MIC-determination of antifungal drugs for dermatophytes species, since it is a less-laborious methodology and results could be obtained faster. Key Words: Dermatophytes, E-test, antifungal ÖzetAmaç: Dermatomikozlar mantarlar tarafından oluşturulan deri, saç ve tırnakları tutan enfeksiyonlardır. Dermatolojide mantar enfeksiyonlarının oral tedavisi yaygın olarak tercih edilen yöntem haline gelmiştir. Dermatofitlerin tedavisi için kullanılan antifungallerin sayısının artmasına rağmen bazı durumlarda tedaviye yanıtsızlık ve nüksler gelişmektedir. İn-vitro antifungal duyarlılığın belirlenmesinin dermatofitlerin etkili olarak tedavi edilmesi için önemli olduğu bildirilmektedir. Antifungal duyarlılığın belirlenmesinde yöntemler önemlidir. E-test (AB Biodisk, İsveç) hızlı ve kolay uygulanabilir bir duyarlılık yöntemidir. Bu çalışmanın amacı, klinik örneklerden izole edilen farklı dermatofit türlerinin beş antifungal ilaca karşı duyarlılık-larını E-test yöntemi ile belirlemektir. ) aralıkları ile itrakonazol olarak bulundu. En az etkili antifungal ise (0, 19-48, 2-256, 2-8, 256, 256, 8-24) MIC (μg/mL -1 ) aralıkları ile flukonazol olarak bulundu. Gereç veSonuç: E-test dermatofit türlerinin antifungal duyarlılığının belirlenmesinde daha az zahmetli ve sonuçların daha hızlı elde edilebilir olması ile alternatif bir yöntem gibi görünmektedir.

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Dermatophyte susceptibilities to antifungal azole agents tested in vitro by broth macro and microdilution methods

Cited by 16 publications

References 22 publications

In vitro activity of azole derivatives and griseofulvin against planktonic and biofilm growth of clinical isolates of dermatophytes

In vitro activity of azole derivatives and griseofulvin against planktonic and biofilm growth of clinical isolates of dermatophytes

Calcofluor White Combination Antifungal Treatments for Trichophyton rubrum and Candida albicans

Investigation of In Vitro Activity of Five Antifungal Drugs against Dermatophytes Species Isolated from Clinical Samples Using the E-Test Method

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