Dermatophyte susceptibilities to antifungal azole agents tested in vitro by broth macro and microdilution methods (original) (raw)
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In vitro susceptibility of seven antifungal agents against dermatophytes isolated in İstanbul
TURKISH JOURNAL OF MEDICAL SCIENCES, 2018
Introduction Dermatophytes are keratinophilic hyaline molds that can cause disease in keratinized tissues like hair, skin, and nail. Depending on the reservoir and route of transmission, dermatophytes may be of anthropophilic (human), zoophilic (animals), or geophilic (soil) origin. Dermatophytes comprise more than 40 species in 3 genera: Microsporum, Trichophyton, and Epidermaphyton. The most common etiological agents are T. rubrum, T. mentagraphytes, T. interdigitale, T. tonsurans, and Microsporum canis. T. rubrum is the most frequently isolated agent in clinics (1). Dermatomycosis refers to diseases caused by yeasts and filamentous molds, whereas diseases caused by dermatophytes are called dermatophytosis (e.g., tinea, ringworm). Dermatophytes are the causative agents of the most common superficial fungal diseases in the world. These organisms are named according to the affected body site: T. capitis (head), T. corporis (trunk), T. cruris (perianal area), T. pedis (foot and interdigital area), and T. unguium (nail). Although the disease can affect individuals of all ages, T. capitis and T. corporis are more common among children, whereas T. pedis is more common among adults (2). The disease is more prevalent among individuals with diabetes and immune system disorders. Transmission can occur via direct contact with infected individuals as well as by sharing of household items such as brushes, shower facilities, carpeting, from household pets, and by autoinoculation (3). Although the infection is neither painful nor lifethreatening, accurate diagnosis and effective treatment are still important since the disease is widespread and contagious, causes aesthetic issues, and lowers life quality. Prolonged treatment may result in significant side effects of the drugs and treatment costs. In cases where infection is mild and localized, topical treatment is applied. Systemic treatment can be administered in chronic severe infections. Emergence of drug resistance, lack of compliance to treatment, and incorrect treatment may delay recovery and cause relapses. High relapse rates may be associated with circulatory impairment, drug interactions, advanced Background/aim: Dermatophytes are the causative agents of dermatophytosis, which is a common disease worldwide that affects the hair, skin, and nails. Dermatophytes comprise more than 40 species in 3 genera: Microsporum, Trichophyton, and Epidermaphyton. In this study, we aimed to determine the effectiveness of seven antifungal agents: amphotericin B, terbinafine, itraconazole, voriconazole, ketoconazole, miconazole, and fluconazole. Materials and methods: A sensitivity study was performed using a microdilution method in accordance with the CLSI M38-A2 standards using isolates of Trichophyton rubrum (n = 55), Microsporum canis (n = 9), and Trichophyton interdigitale (n = 2), which were identified by sequencing the internal transcribed spacer region of the rDNA. Results: According to the results of antifungal sensitivity tests, the geometric mean (GM) minimum inhibitory concentration (MIC) against T. rubrum was 0.10 µg/mL for ketoconazole, 0.20 µg/mL for itraconazole, 0.07 µg/mL for miconazole, 0.48 µg/mL for fluconazole, 2.27 µg/mL for amphotericin B, 0.06 µg/mL for voriconazole, and 0.06 µg/mL for terbinafine. Conclusion: The most effective antifungal drugs were voriconazole and terbinafine, both of which had a GM MIC of 0.06 µg/mL.
Low in vitro activity of sertaconazole against clinical isolates of dermatophyte
Current Medical Mycology, 2020
Background and Purpose: Dermatophytes are a group of fungi specialized in invading humans and other vertebrate keratinized tissues. These fungi cause a variety of skin, nail, and hair disorders, called dermatophytosis (tinea). In some cases, drug resistance to antifungals necessitates special treatment. Among the antifungal agents, sertaconazole (i.e., a third-generation imidazole) has a broad-spectrum against dermatophyte species. Regarding this, the present study was conducted to investigate the antifungal susceptibility of dermatophytes obtained from patients with dermatophytosis in Mashhad located in northeastern Iran. Materials and Methods: A total of 75 clinical dermatophyte isolates, including Trichophyton mentagrophytes (n=21), T. interdigital (n=18), T. tonsurans (n=16), Epidermophyton floccosum (n=11), Microsporum canis (n=5), Nannizzia fulvum (n=2), T. benhamiae (n=1), and T. verrucosum (n=1), were evaluated against five antifungal agents of sertaconazole, itraconazole, c...
Revista Do Instituto De Medicina Tropical De Sao Paulo, 2009
The antifungal activities of fluconazole, itraconazole, ketoconazole, terbinafine and griseofulvin were tested by broth microdilution technique, against 60 dermatophytes isolated from nail or skin specimens from Goiania city patients, Brazil. In this study, the microtiter plates were incubated at 28 o C allowing a reading of the minimal inhibitory concentration (MIC) after four days of incubation for Trichophyton mentagrophytes and five days for T. rubrum and Microsporum canis. Most of the dermatophytes had uniform patterns of susceptibility to the antifungal agents tested. Low MIC values as 0.03 µg/mL were found for 33.3%, 31.6% and 15% of isolates for itraconazole, ketoconazole and terbinafine, respectively.
Journal of the American Academy of Dermatology, 1999
As a prerequisite to standardization of dermatophyte susceptibility testing, conditions that support optimal growth of different dermatophyte species must be established. Eighteen isolates of Trichophyton spp. (T rubrum, T mentagrophytes, T tonsurans) were grown in 4 different media: RPMI 1640 with L-glutamine, without sodium bicarbonate and buffered at pH = 7.0; antibiotic medium #3 (Penassay); yeast nitrogen base with 0.5% dextrose buffered at pH = 7.0; and Sabouraud dextrose broth. Incubation for 6 days at 35 degrees C produced the following results: RPMI and Sabouraud dextrose supported equally sufficient growth for all strains tested; Penassay supported growth of only 33% of the isolates tested, and buffered yeast nitrogen base did not support growth of any isolates. RPMI was selected as the optimal medium, and organisms were tested at both 30 degrees C and 35 degrees C with a standardized inoculum density of 10(3) conidia/mL. No temperature differences were noted in the amount of growth of the dermatophytes tested. With RPMI at an incubation temperature of 35 degrees C, 3 inoculum sizes (10(3), 10(4), and 10(5) conidia/mL) were tested against 4 antifungal agents: griseofulvin, itraconazole, terbinafine, and fluconazole. Inoculum size did not affect minimum inhibitory concentration (MIC) results for itraconazole or terbinafine, but a larger inoculum produced a slightly higher MIC for griseofulvin and a noticeably higher MIC for fluconazole. Our data support the use of RPMI 1640, 35 degrees C, and 4 days as an incubation temperature and time, respectively, and an inoculum of 10(3) conidia/mL as optimal conditions for the determination of the antifungal susceptibility of dermatophytes.
Diagnostic Microbiology and Infectious Disease, 2004
The antifungal activities of fluconazole, itraconazole, ketoconazole, terbinafine and griseofulvin were tested by broth microdilution technique, against 60 dermatophytes isolated from nail or skin specimens from Goiania city patients, Brazil. In this study, the microtiter plates were incubated at 28 o C allowing a reading of the minimal inhibitory concentration (MIC) after four days of incubation for Trichophyton mentagrophytes and five days for T. rubrum and Microsporum canis. Most of the dermatophytes had uniform patterns of susceptibility to the antifungal agents tested. Low MIC values as 0.03 µg/mL were found for 33.3%, 31.6% and 15% of isolates for itraconazole, ketoconazole and terbinafine, respectively.
In vitro susceptibility of dermatophytes to conventional and alternative antifungal agents
Medical …, 2008
The minimum inhibitory concentrations (MICs), the minimal fungicidal concentrations (MFCs), the fungal biomass (FB) and hyphal viability employing the dye 3-4,5 dimethyl-2-thiazolyl-2,5-diphenyl-2H tetrazolium bromide (MTT) were used to compare the in vitro effects of fluconazole (FLU) with those of the Nterminal palmitoyl-lipidated peptide, Pal-Lys-Lys-NH 2 (PAL), and a tea tree oil component, g-Terpinene (TER), against several clinical isolates of Microsporum canis and Trichophyton rubrum. In general, FLU and PAL MICs were significantly lower than those observed with TER, while no differences in the three drugs were found in the MFCs. However, they were from two to 16-times higher than their respective MICs. FB of M. canis treated with either FLU or PAL, but not with TER, was significantly reduced over untreated controls. Only PAL and TER, in a medium-dependent fashion, but not FLU, reduced the FB of T. rubrum. Finally, PAL was found to be significantly more active than FLU at reducing the hyphal viability against both genera of dermatophytes. This study shows that PAL exerts an in vitro activity against dermatophytes at least similar to that observed with FLU and suggests that this compound might be a promising candidate in the treatment of infections due to dermatophytes.
Antimicrobial agents and chemotherapy, 2018
The objective of this study was to assess the activity of the novel triazole antifungal drug, efinaconazole, and five comparators (luliconazole, lanoconazole, terbinafine, itraconazole, and fluconazole) against a large collection of and clinical isolates. The geometric mean MICs were the lowest for luliconazole (0.0005 μg/ml), followed by lanoconazole (0.002 μg/ml), efinaconazole (0.007 μg/ml), terbinafine (0.011 μg/ml), itraconazole (0.095 μg/ml), and fluconazole (12.77 μg/ml). It appears that efinaconazole, lanoconazole, and luliconazole are promising candidates for the treatment of dermatophytosis due to and .
IP innovative publication pvt. ltd, 2020
Dermatophytosis is one of the most common cutaneous fungal infections in India. Despite, quite a few numbers of antifungal agents available for treatment, the resistance to antifungals by dermatophytes is increasing day by day as seen by doctors in clinical practice. Itraconazole has shown good results in the treatment of dermatophytosis at doses of 100 mg once a day for 2 weeks and with 200 mg once a day for 7 days. However, there are multiple itraconazole brands available in India. In this study, five different itraconazole brands were evaluated in vitro for MIC values against clinical isolates of Trichophyton mentagrophytes and Trichophyton rubrum by two different methods i.e. broth dilution and disc diffusion tests. It was found that the Reference brand of itraconazole and the test brand of Itraconazole showed least MIC values as compared to other available brands.
Medical mycology, 2016
In vitro susceptibilities of 100 clinical dermatophyte isolates belonging to five species from Iran toward lanoconazole and luliconazole were compared with ten other antifungal agents including econazole, itraconazole, miconazole, fluconazole, griseofulvin, butenafine, terbinafine, caspofungin, anidulafungin and tolnaftate. MIC and MEC values were analyzed according to CLSI M38-A2 document. The isolates were previously identified to the species level using PCR-RFLP on ITS rDNA region. The range of luliconazole and lanoconazole minimum inhibitory concentrations (MICs) was 0.016-0.032 and 0.063-1 μg/ml, respectively for dermatophyte species. Luliconazole and lanoconazole revealed potent activity against all dermatophyte isolates. Anidulafungin, caspofungin, and luliconazole showed the best activity with the lowest geometric mean 0.01, 0.016, and 0.018 μg/ml, respectively, followed by tolnaftate (0.06 μg/ml), terbinafine (0.07 μg/ml), itraconazole (0.183 μg/ml), butenafine (0.188 μg/ml...
Mycoses, 2018
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 meta...