Clinical Isolates Of Dermatophytes Research Articles

In vitro antifungal activity of eucalyptol and its interaction with antifungal drugs against clinical dermatophyte isolates including Trichophyton indotineae

BackgroundDermatophytosis, a prevalent fungal infection, often exhibits treatment failure. It poses ongoing public health concerns, urging exploration of alternative treatment strategies. This study examines eucalyptol’s in vitro activity and its interaction with antifungal agents against dermatophyte isolates.MethodsOverall, 489 patients clinically suspected of dermatophytosis were investigated, and the causative agents were molecularly identified. The antifungal activity of eucalyptol, itraconazole, terbinafine, and griseofulvin was assessed according to the guideline of the Clinical and Laboratory Standards Institute (CLSI M38 ed3). The interaction between eucalyptol and the aforementioned antifungals was determined using a checkerboard method.ResultsDermatophytosis was confirmed in 30 out of 489 (6.13%) patients, with a female-to-male ratio of 3:2 and an age range of 8–67 years. The most commonly observed clinical manifestation was tinea corporis (34.21%), and Trichophyton indotineae (n = 14, 46%) was the most common causative agent. Antifungal susceptibility testing revealed that eucalyptol exhibited antidermatophyte properties with minimum inhibitory concentrations (MIC) ranging from 0.78 to 25 mg/mL. Itraconazole demonstrated the lowest geometric mean (GM) value (MIC range: 0.0019–0.25 µg/mL, GM: 0.015 µg/mL), while griseofulvin exhibited the highest GM value (MIC range: 0.125–8 µg/mL, GM: 2.37 µg/mL). The in vitro interaction of eucalyptol with antifungal drugs, except for its combination with terbinafine against two Trichophyton tonsurans isolates resulting in synergistic effects, showed indifference (n = 70, 77.77%) and antagonistic types (n = 18, 20%).ConclusionAmong the evaluated antifungals, itraconazole demonstrated the highest effectiveness against clinical isolates, while eucalyptol alone exhibited a more pronounced effect than when combined with antifungal agents.

Antifungal Activity of Efinaconazole Compared with Fluconazole, Itraconazole, and Terbinafine Against Terbinafine- and Itraconazole-Resistant/Susceptible Clinical Isolates of Dermatophytes, Candida, and Molds.

Recently, an increasing number of resistant-to-terbinafine dermatophytosis cases have been reported. Thus, identifying an alternative antifungal agent that possesses broad-spectrum activity, including against resistant strains, is needed. We compared the antifungal activity of efinaconazole with that of fluconazole, itraconazole, and terbinafine against clinical isolates of dermatophytes, Candida, and molds using in vitro assays. Minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of each antifungal agent were quantified and compared. Susceptible and resistant clinical isolates of Trichophyton mentagrophytes (n = 16), Trichophyton rubrum (n = 43), Trichophyton tonsurans (n = 18), Trichophyton violaceum (n = 4), Candida albicans (n = 55), Candida auris (n = 30), Fusarium spp, Scedosporium spp, and Scopulariopsis spp (n = 15 for each) were tested. Efinaconazole was the most active antifungal agent tested against dermatophytes, with MIC50 and MIC90 (concentrations that inhibited 50% and 90% of strains tested, respectively) values of 0.002 and 0.03 µg/mL, respectively. Fluconazole, itraconazole, and terbinafine showed MIC50 and MIC90 values of 1 and 8 µg/mL, 0.03 and 0.25 µg/mL, and 0.03 and 16 µg/mL, respectively. Against Candida isolates, efinaconazole MIC50 and MIC90 values were 0.016 and 0.25 µg/mL, respectively, whereas fluconazole, itraconazole, and terbinafine had MIC50 and MIC90 values of 1 and 16 µg/mL, 0.25 and 0.5 µg/mL, and 2 and 8 µg/mL, respectively. Against various mold species, efinaconazole MIC values ranged from 0.016 to 2 µg/mL versus 0.5 to greater than 64 µg/mL for the comparators. Efinaconazole showed superior potent activity against a broad panel of susceptible and resistant dermatophyte, Candida, and mold isolates.

Epidemiological studies and antifungal sensitivity pattern of clinical isolates of dermatophytes from localized cases of canine dermatophytosis

Epidemiological studies and antifungal sensitivity pattern of clinical isolates of dermatophytes from localized cases of canine dermatophytosis

Role of Sertaconazole in the Treatment of Dermatophytosis

Dermatophytosis is a major health burden worldwide and is now increasing day by day. Dermatophytosis is also becoming increasingly unresponsive to topical conventional antifungals now a day. Newer topical antifungals may be more effective in these patients. Sertaconazole is a new, broad spectrum, fungicidal and fungistatic imidazole with added antipruritic and anti-inflammatory activity that may be effective and beneficial in improving the quality of life for the patient with dermatophytoses. It is indicated in the European Union(EU) for the treatment of superficial skin mycoses such as dermatophytosis (including tinea corporis, tinea cruris, tinea manus, tinea barbae and tinea pedis), cutaneous candidiasis, pityriasis versicolor and seborrhoeic dermatitis of the scalp, and in the US for tinea pedis only. Sertaconazole has broad-spectrum antifungal activity against dermatophytes of the Trichophyton, Epidermophyton and Microsporum genera, and yeasts of the genera Candida and Cryptococcus; additionally, it is effective against opportunistic filamentous fungi and Gram-positive bacteria. Moreover, the antifungal activity of sertaconazole is maintained in clinical isolates of dermatophytes that show reduced susceptibility to other azoles. While the drug has good dermal penetration, this is not associated with systemic absorption. In clinical trials in patients with superficial mycoses, 2% sertaconazole cream applied twice daily was effective in the eradication of a range of dermatophytoses, and a significantly greater proportion of patients were cured compared with those receiving 2% miconazole cream twice-daily treatment. Both as a topical cream and suppository preparation, sertaconazole was generally well tolerated. Sertaconazole is a well-established antifungal agent, which is now available in a variety of formulations, and remains a useful treatment option particularly in patients with fungal infections resistant to other azoles. Medicine Today 2023 Vol.36 (1): 62-66

ЧУВСТВИТЕЛЬНОСТЬ ВОЗБУДИТЕЛЕЙ ДЕРМАТОФИТИЙ К ПРОТИВОГРИБКОВЫМ СРЕДСТВАМ, АНТИСЕПТИКАМ И ДЕЗИНФЕКТАНТАМ

Dermatophytes form the group of fungal pathogens of humans, which includes 43 species, of which the most important representatives are the genera Trichophyton and Microsporum. In recent years, patients with the established diagnoses of “mycosis pedis“, "skin mycosis of the palms“ and "onychomycosis”, and associations of dermatophytes and moulds as well as dermatophytes as an aetiological factor in mixed infections and yeast-like fungi often play a role. The main objective of the current study was to determine the susceptibility of dermatophytosis pathogens (Trichophyton spp., Microsporum spp.) isolated from samples of biological from patients with mycoses to modern antifungals, antiseptics and disinfectants. Within the framework of this study, 142 clinical isolates of dermatophytes identified as Trichophyton spp. (n=68) and Microsporum spp. (n=74) were obtained from patients with diagnoses of "B35.3 Mycosis of the feet", "B35.0 Microsporia". It was found that the most active antifungal agents against clinical isolates of dermatophytes are itraconazole, terbinafine and amphotericin B. Among the studied clinical isolates of Trichophyton spp. in Microsporum spp. conditionally resistant strains to the studied antimycotics have been identified. Most of the studied clinical isolates of dermatophytes were high sensitive to antiseptics based on iodine, fucorcinol, undecylenic and boric acids. Disinfectants based on aldehydes, guanidine derivatives, triamines, and glycolic acid showed the greatest activity against clinical isolates of dermatophytes. Based on our data, preference should be given to amphotericin B, itraconazole and terbinafine-based drugs when prescribing ethiotropic therapy for patients with dermatomycosis. It is advisable to use antipseptics and disinfectants for dermatomycosis, taking into account the sensitivity of micromycetes to them.

Analysis of ERG 11 expression in clinical isolates of dermatophytes in patients with resistant Tinea infection.

Background: Dermatophytes are keratinophilic groups of microorganisms which invade keratinized tissue.
 Objective:1 - Isolate and identify the dermatophyte species from samples collected from patients suffering from onychomycosis, tinea corporis and tinea cruris; and perform in vitro microbroth antifungal susceptibility testing.
 Objective:2 - Further, the expression of Ergosterol 11 (ERG 11) amongst the isolates from responders and non-responders to antifungal treatment was studied by Real-time PCR.
 Methods & Results: A total of 120 dermatophytosis cases attending a dermatological clinic in a tertiary care hospital were included in the study. Microscopy of KOH mount was positive in 90 isolates while 60 were culture positive. The most common dermatophytes implicated were Trichophyton mentagrophytes (75%) followed by Trichophyton rubrum (25%) which were molecularly confirmed by PCR using the species-specific primer. Higher MIC was detected for fluconazole (10 %), itraconazole (3.33 %), terbinafine (10 %) and griseofulvin (5 %), for T. mentagrophytes and T rubrum, while all strains showed lower MIC for voriconazole and luliconazole.
 Interpretation & Conclusion: The study observed a predominance of T. mentagrophytes causing chronic dermatophytosis. The rising MIC to terbinafine and griseofulvin among the isolates raises a concern for effective management. The real-time PCR analysis of ERG 11 expression in certain isolates demonstrated up-regulation in patients not responding to treatment as compared to responders, the impending failure of azoles as a line of treatment in dermatophytosis.

Antifungal Activity of Nontoxic Nanocomposite Based on Silver and Reduced Graphene Oxide against Dermatophytes and Candida spp.

Dermatomycoses are typical hair, skin, or nail infections caused mainly by dermatophytes and nondermatophytes: Trichophyton, Microsporum, Epidermophyton, and Candida. In addition to the esthetical impact, pain, and nail deformity, these mycoses can be a source of severe disease. The high cost of treatment, toxicity, and the emergence of resistant infectious agents justifies research into new drugs. This work evaluates the fungicidal activity of nanocomposites (NCs) based on reduced graphene oxide (rGO) loaded with silver (Ag) nanoparticles (rGO/Ag) against clinical isolates of dermatophytes and Candida species. This is an unprecedented study in which, for the first time, hybrid nanocompounds based on Ag/rGO were tested against Epidermophytom, Microsporum, and Trichophyton species (dermatophytes agents). In this paper, we synthesize rGO using different concentrations of Ag by hydrolysis of metal salt AgNO3 and follow the growth of nanocrystals on sheets of rGO provided by the NaBH4. The NCs were analyzed by X-ray diffraction analysis, and the NC morphology, silver distribution on the rGO surface, and crystalline information were investigated by transmission electron microscopy. Antifungal susceptibility assay was performed by the microdilution method based on modified Clinical and Laboratory Standards Institute (CLSI) protocol. Time-kill kinetics was conducted to monitor the effect of the composite to inhibit fungal cells or promote structural changes, avoiding germination. The toxicological evaluation of the NCs was born in an in vivo model based on Galleria mellonella (G. mellonella). Minimum inhibitory concentration (MIC) values of the rGO/Ag NCs ranged from 1.9 to 125 μg/mL. The best inhibitory activity was obtained for rGO/Ag12%, mainly against Candida spp. and Epidermophyton floccosum. In the presence of sorbitol, MIC values of rGO/Ag NCs were higher (ranging from 15.6 to 250 μg/mL), indicating the action mechanism on the cell wall. Both yeast and dermatophytes clinical isolates were inhibited at a minimum of 6 and 24 h, respectively, but after 2 and 12 h, they had initial antifungal interference. All hybrid formulations of rGO/Ag NCs were not toxic for G. mellonella. This study provides insights into an alternative therapeutic strategy for controlling dermatomycoses.

Phytoconstituents and antidermatophytic activity of crude extracts of Senna occidentalis

Dermatophytes are one of the major aetiologic agents of cutaneous mycoses Senna occidentalis is among the plants used in traditional herbal medicine in treating fungal skin infections and it is shown from literature to contain phytochemicals which are attributed to its antidermatophytic activity. This work is aimed at determining the Phytoconstituents and antidermatophytic activity of leaves and seeds crude extracts of the Senna occidentalis plant . The study is a qualitative study that determines the phytoconstituents and antidermatophytic activity of the plant extracts on some clinical dermatophyte isolates. The plant parts were sampled and were used to obtain aqueous and n-hexane extracts using distilled water and n-hexane as extracting solvents respectively. Phytochemical analysis was done on the extracts to determine the presence of secondary metabolites. The antidermatophytic activity of the extracts on clinical dermatophytes isolates was determined using poisoned food technique. Aqueous extraction gave higher percentage extraction yield than n-hexane extract . All extracts contain secondary metabolites and the extracts showed varying degree of percentage growth inhibition on the isolates. Phytochemical screening of the leaves and seeds extracts of Senna occidentalis revealed the presence of alkaloids, saponins, tannins and other phytoconstituents. The Senna occidentalis leaves and seeds extracts showed growth inhibition percentage (I) ranging between 9% to 39.8% for n-hexane leaf extract,1.3% to 52.6% for aqueous leaf extract,2.6% to 57.2% for n-hexane seed extract and 12.8% to 61.1% for aqueous seed extract. Senna occidentalis leaves and seeds extract have shown varying potential in inhibiting dermatophyte growth with no extract having 100% inhibition percentage on all the tested dermatophytes.

Phenotypic and Genotypic Identification of Dermatophytes from Mexico and Central American Countries.

Dermatophytes are fungi included in the genera Trichophyton, Microsporum, Epidermophyton, Nannizzia, Paraphyton, Lophophyton, and Arthroderma. Molecular techniques have contributed to faster and more precise identification, allowing significant advances in phylogenetic studies. This work aimed to identify clinical isolates of dermatophytes through phenotypic (macro- and micromorphology and conidia size) and genotypic methods (sequences of ITS regions, genes of β tubulin (BT2), and elongation factor α (Tef-1α)) and determine the phylogenetic relationships between isolates. Ninety-four dermatophyte isolates from Costa Rica, Guatemala, Honduras, Mexico, and the Dominican Republic were studied. The isolates presented macro- and micromorphology and conidia size described for the genera Trichophyton, Microsporum, and Epidermophyton. Genotypic analysis classified the isolates into the genera Trichophyton (63.8%), Nannizzia (25.5%), Arthroderma (9.6%), and Epidermophyton (1.1%). The most frequent species were T. rubrum (26 isolates, 27.6%), T. interdigitale (26 isolates, 27.6%), and N. incurvata (11 isolates, 11.7%), N. gypsea and A. otae (nine isolates, 9.6%), among others. The genotypic methods clarified the taxonomic status of closely related species. For instance, the ITS and BT2 markers of T. rubrum/T. violaceum did not differ but the Tef-1α gene did. On the other hand, the three markers differed in T. equinum/T. tonsurans. Therefore, the ITS, BT2, and Tef-1α genes are useful for typing in phylogenetic analyses of dermatophytes, with Tef-1α being the most informative locus. It should be noted that isolate MM-474 was identified as T. tonsurans when using ITS and Tef-1α, but when using BT2, it was identified as T. rubrum. On the other hand, no significant difference was found when comparing the methods for constructing phylogenies, as the topologies were similar.

Analysis of Mannose-Binding Lectin Protein Levels and their MIC Profile in Patients with Dermatophytosis.

Analysis of Mannose-Binding Lectin Protein Levels and their MIC Profile in Patients with Dermatophytosis.

Appraisal of selected ethnomedicinal plants as alternative therapies against onychomycosis: Evaluation of synergy and time-kill kinetics.

Introduction: This study aims at the biological profiling of Allium sativum, Zingiber officinale, Nigella sativa, Curcuma longa, Mentha piperita, Withania somnifera, Azadirachta indica, and Lawsonia inermis as alternatives against onychomycosis to combat the treatment challenges. Methods: An extract library of aqueous (DW), ethyl acetate (EA), and methanol (M) extracts was subjected to phytochemical and antioxidant colorimetric assays to gauge the ameliorating role of extracts against oxidative stress. RP-HPLC quantified therapeutically significant polyphenols. Antifungal potential (disc diffusion and broth dilution) against filamentous (dermatophytes and non-dermatophytes) and non-filamentous fungi (yeasts; Candida albicans), synergistic interactions (checkerboard method) with terbinafine and amphotericin-B against resistant clinical isolates of dermatophytes (Trichophyton rubrum and Trichophyton tonsurans) and non-dermatophytes (Aspergillus spp., Fusarium dimerum, and Rhizopus arrhizus), time-kill kinetics, and protein estimation (Bradford method) were performed to evaluate the potential of extracts against onychomycosis. Results: The highest total phenolic and flavonoid content along with noteworthy antioxidant capacity, reducing power, and a substantial radical scavenging activity was recorded for the extracts of Z. officinale. Significant polyphenolics quantified by RP-HPLC included rutin (35.71 ± 0.23µg/mgE), gallic acid (50.17 ± 0.22µg/mgE), catechin (93.04 ± 0.43µg/mgE), syringic acid (55.63 ± 0.35µg/mgE), emodin (246.32 ± 0.44µg/mgE), luteolin (78.43 ± 0.18µg/mgE), myricetin (29.44 ± 0.13µg/mgE), and quercetin (97.45 ± 0.22µg/mgE). Extracts presented prominent antifungal activity against dermatophytes and non-dermatophytes (MIC-31.25μg/ml). The checkerboard method showed synergism with 4- and 8-fold reductions in the MICs of A. sativum, Z. officinale, M. piperita, L. inermis, and C. longa extracts and doses of amphotericin-B (Amp-B) and terbinafine (against non-dermatophytes and dermatophytes, respectively). Furthermore, the synergistic therapy showed a time-dependent decrease in fungal growth even after 9 and 12h of treatment. The inhibition of fungal proteins was also observed to be higher with the treatment of synergistic combinations than with the extracts alone, along with the cell membrane damage caused by terbinafine and amp-B, thus making the resistant fungi incapable of subsisting. Conclusion: The extracts of A. sativum, Z. officinale, M. piperita, L. inermis, and C. longa have proven to be promising alternatives to combat oxidative stress, resistance, and other treatment challenges of onychomycosis.

P076 The promising antimycotic activities of a novel cyclic antifungal lipopeptide against Human Dermatophyte Isolates

Poster session 1, September 21, 2022, 12:30 PM - 1:30 PMObjectivesTo determine the minimum inhibitory concentrations (MICs) of a novel antifungal lipopeptide against clinical isolates of dermatophytes of human origin.MethodsTo perform antifungal susceptibility testing (AFST) by CLSI microbroth dilution method, a reversed-phase high-performance liquid chromatography (RP-HPLC) purified lipopeptide of 1071.4 Da from a wild-type soil isolate Bacillus subtilis was used and compared with the standard allylamine terbinafine MICs. Briefly, 1200 ml of cell-free culture supernatant was extracted using a solvent mixture and silica gel (230-400 mesh size)-based adsorption chromatography. The semi-preparative RP-HPLC system consisted of an Agilent quaternary pump and a variable wavelength detector equipped with a Phenomenex Luna C18 column (10 mm × 250 mm, 5 μm). The solvent system for RP- HPLC was (A) water with 0.1% trifluoroacetic acid (TFA) and (B) acetonitrile containing 0.1% TFA. The gradient of solvent B used for purification was as follows: 0%-54% for 0-20 min at the flow rate of 1 ml/min, 54%-60% from 20-48 min at 0.5 ml/min, 60%-100% from 48-58 min at 0.5 ml/min, 100%-0% from 58-65 min at 1 ml/min and monitored at 210 nm.ResultsSuperficial skin infections are caused by dermatophytes including Trichophyton spp. Nowadays, resistance to terbinafine in Trichophyton spp. isolates with higher MICs have been documented in India. We report here the antifungal prowess of a novel small antifungal lipopeptide against 20 clinical isolates of Trichophyton spp. of human origins (from human skin scrapings and nails) with the clinical diagnosis of tinea corporis/cruris and tinea unguium. The representative photographs of T. tonsurans, T. rubrum, and T. mentagrophytes complex are provided below. A total of 6 isolates of T. mentagrophytes and T. rubrum carry point mutations at F397L of squalene epoxidase (SQLE) protein. The in vitro antifungal efficacies determined by AFST revealed that the lipopeptide showed less or equivalent MICs (100% inhibition) in the case of five dermatophytes. The lipopeptide drug has exhibited improved MICs against two T. mentagrophytes complex and two T. rubrum isolates with amino acid substitution F397L in SQLE protein. Trichophyton mentagrophytes complex and T. rubrum with F397L mutations were inhibited at MICs 4-32 μg/mL of terbinafine. In comparison, the lipopeptide showed 4-16 μg/ml (100% inhibition). In the case of all four Trichophyton tonsurans, the MICs ranged between 2-4 μg/ml for the lipopeptide.ConclusionsThe broad-spectrum lipopeptide showed promising antifungal activity against dermatophytes and may be considered for nano-emulsion formulation and tested for topical application in a mice model.

Quantitative analysis of in vitro biofilm formation by clinical isolates of dermatophyte and antibiofilm activity of common antifungal drugs.

The ability of dermatophytes to develop biofilm, as one of the virulence factors in fungal infections which contribute to antifungal resistance, is an outstanding aspect of dermatophytosis that has been noted recently. Because of the paucity of data about the biofilm formation by dermatophytes and their susceptibility to antifungal drugs, this study evaluated the biofilm formation by clinical isolates of dermatophytes and antibiofilm activity of common antifungals widely used to manage dermatophytosis. The ribosomal DNA internal transcribed spacer (ITS) regions sequencing for species identification of 50 clinical dermatophyte isolates was performed. The ability of isolates to form biofilm and inhibitory activity of itraconazole, terbinafine, and griseofulvin against biofilm formation was assayed by the crystal violet staining method. Optical microscopy and scanning electron microscopy (SEM) were applied for the visualization of the biofilm structures. Trichophyton (T.) mentagrophytes (n: 14; 28%) and T. rubrum (n: 13;26%) were included in more than half of the dermatophyte isolates. Biofilm formation was observed in 37 out of 50 (74%) isolates that were classified as follows: nonproducers (n: 13; 26%), weak producers (n: 4; 8%), moderate producers (n: 16; 32%), and strong producers (n: 17; 34%) by comparison of the absorbance of biofilms produced by clinical strains with control. The mean IC50 values for terbinafine, griseofulvin, and itraconazole were 2.42, 3.18, and 3.78 μg/ml, respectively. The results demonstrated that most of the clinical dermatophyte isolates are capable to form biofilm in vitro with variable strength. Moreover, terbinafine can be suggested as the first-line choice for the treatment of biofilm-formed dermatophytosis.

Identification of Dermatophyte Species by PCR Restriction Fragment Length Polymorphism in Ramallah region, Palestine

Dermatophytes are a group of fungi that cause an infection called dermatophytosis. They are mainly classified into three anamorphic genera: Trichphyton, Microsporum and Epidermophyton. Sixty-five samples were collected during the period from the middle of January to the end of September of the year 2019. The clinical specimens (hair, nail and skin) were collected from 58 patients who were clinically diagnosed with dermatophytosis. Molecular identification was done by using the fungus-specific universal primers (ITS1 and ITS4) for the amplification of the ITS region in the rRNA gene. For species identification, BstN1 restriction enzyme was used for the digestion of the amplified ITS products to produce distinct band patterns. The distribution of dermatophytosis among the patients was 52.3.%, 41.5%, 3.1%, 1.5% and 1.5% for Tinea nail, Tinea capitis, Tinea corporis, Tinea pedis and Tinea imbricate, respectively. Nighnteen clinical isolates of dermatophytes showed positive culture. Trichophyton was the most common genus with 15 sample (78.9%), followed by Microsporum with 4 samples (21.1%) and no Epidermophyton were found. The most common species was T. rubrum (n=5, 26.3%), followed by T. verrucosum (n=3, 15.8%), then T. mentagrophytes, M. Canis, M. audouinii and T. schoenleinii with tow isolates for each (10.5%). The amplification of ITS regions was successful in certain samples by using the fungus-specific universal primers (ITS1 and ITS4) and PCR-RFLP technique

Diagnosis and in vitro antidermatophytic sensitivity of the ethanolic extract of Euphorbia tirucall / Diagnóstico e sensibilidade antidermatófita in vitro do extrato etanólico de Euphorbia tirucalli

Dermatophytosis is the most common mycosis, accounting for 5 to 10% of all superficial mycoses. The present study aimed to evaluate the in vitro antifungal activity of the ethanolic extract of Euphorbia tirucalli on clinical isolates of dermatophytes obtained from 2 patients with signs and symptoms consistent with dermatophyte infection. Two dermatophyte etiologic agents, Trichophyton mentagrophytes and T. tonsurans, were isolated from these patients. In vitro antifungal sensitivity showed that the ethanolic extract of E. tirucalli possesses antifungal activity against these strains of interest, with a Minimum Inhibitory Concentration (MIC) of 125 and 250 g/mL, respectively. According to the phytochemical profile of this extract supported by infrared analysis, the antibiotic activity was attributed to the presence of flavonoids and tannins, phytoconstituents generally recognized for their pharmacological potential.

Phylogeny, Antifungal Susceptibility, and Point Mutations of SQLE Gene in Major Pathogenic Dermatophytes Isolated From Clinical Dermatophytosis.

Drug resistance is one of the major challenges to skin fungal infections, especially in tropical and subtropical infections caused by dermatophytes. This study aimed to determine the antifungal susceptibility of clinically dermatophytes and evaluate point mutations in terbinafine-resistant isolates. A total number of 123 clinical dermatophyte isolates in eight species were evaluated in terms of sensitivity to seven major antifungals. Furthermore, the point mutation in squalene epoxidase (SQLE) gene responsible for terbinafine resistance was studied. The dermatophytes species were identified by morphological characteristics and confirmed by the ITS sequencing. Also, the phylogenetic tree was drawn using the RAxML analyses for 123 dermatophytes isolates. A new XXIX genotype was also found in 4 Trichophyton mentagrophytes isolates. Based on the results obtained, terbinafine was the most effective antifungal drug followed by itraconazole and voriconazole. Trichophyton rubrum and Trichophyton tonsurans were the most susceptible species (MIC50 = 0.01, 0.09 μg/ml), and T. mentagrophytes was the most resistant species (MIC50 = 0.125 μg/ml) to terbinafine. Of the 123 dermatophytes isolates, six isolates showed reduced susceptibility to terbinafine, and only Trichophyton indotineae had a mutation in SQLE gene as a Phe397Leu substitution. Overall, the antifungal susceptibility test is necessary for managing dermatophytosis. These results help physicians to control the course of the disease and provide further insights to select effective drugs for patients with dermatophytosis, especially in tropical and subtropical regions of the world, where dermatophytosis is still a public health problem.

Update on dermatophytosis in Mashhad, Northeastern Iran, emergence of infection with Trichophyton persicum.

Background:Dermatophytosis is a common global superficial mycosis caused by a group of keratinophilic moulds known as dermatophytes that invade the skin and keratinized tissues such as hair and nails of humans and animals. This study takes identification of a collection of clinical dermatophyte isolates by using partial sequencing of translation elongation factor-1α (Tef-1α) gene aiming both to update the epidemiological status of dermatophytosis in Mashhad, Northeastern Iran and to corroborate the efficacy of Tef-1α for species-level identification of dermatophytes.Method:The demographic data related to 87 culture-positive dermatophytes isolated from patients clinically suspected to have dermatophytosis were collected. The dermatophyte isolates were subjected to a partial polymerase chain reaction (PCR)-sequencing of Tef-1α gene by using specific pan-dermatophyte primers. The data were analysed by SeqMan software, the sequences were compared and aligned with the GenBank database and the isolates were identified.Results:Identification based on Tef-1α partial sequence was successful for all isolates. The identified dermatophyte isolates in decreasing order were as Trichophyton interdigitale 19 (22%), T. tonsurans 19 (22%), T. mentagrophytes 13 (15%), T. persicum 10 (11.5%), Epidermophyton floccosum 9 (10.3%), Microsporum canis 7 (8%), T. rubrum 5 (5.7%), T. violaceum 2 (2.2%), Nannizzia fulva 2 (2.2%) and N. persicolor 1 (1.1%). The isolates have been associated with clinical forms of tinea corporis (n = 38; 43.7%), tinea faciei (n = 13; 15%), tinea cruris (n = 12; 13.9%), tinea manuum (n = 7; 8%), tinea unguium (n = 7; 8%), tinea capitis (n = 7; 8%) and tinea pedis (n = 3; 3.4%).Conclusion:Dermatophytosis has yet remained a public health problem in Northeastern Iran, and infection with new and less frequent species, e.g., T. persicum, N. fulva and N. persicolor have emerged. The Tef-1α gene partial sequencing reconfirmed the resolution power of this locus for the determination of species boundaries in dermatophytes.

Antifungal Combinations in Dermatophytes.

Dermatophytes are the most common cause of fungal infections worldwide, affecting millions of people annually. The emergence of resistance among dermatophytes along with the availability of antifungal susceptibility procedures suitable for testing antifungal agents against this group of fungi make the combinatorial approach particularly interesting to be investigated. Therefore, we reviewed the scientific literature concerning the antifungal combinations against dermatophytes. A literature search on the subject performed in PubMed yielded 68 publications: 37 articles referring to in vitro studies and 31 articles referring to case reports or clinical studies. In vitro studies involved over 400 clinical isolates of dermatophytes (69% Trichophyton spp., 29% Microsporum spp., and 2% Epidermophyton floccosum). Combinations included two antifungal agents or an antifungal agent plus another chemical compound including plant extracts or essential oils, calcineurin inhibitors, peptides, disinfectant agents, and others. In general, drug combinations yielded variable results spanning from synergism to indifference. Antagonism was rarely seen. In over 700 patients with documented dermatophyte infections, an antifungal combination approach could be evaluated. The most frequent combination included a systemic antifungal agent administered orally (i.e., terbinafine, griseofulvin, or azole—mainly itraconazole) plus a topical medication (i.e., azole, terbinafine, ciclopirox, amorolfine) for several weeks. Clinical results indicate that association of antifungal agents is effective, and it might be useful to accelerate the clinical and microbiological healing of a superficial infection. Antifungal combinations in dermatophytes have gained considerable scientific interest over the years and, in consideration of the interesting results available so far, it is desirable to continue the research in this field.

Antifungal susceptibility of dermatophytes from racehorses in Japan.

Luliconazole (LCZ) is an imidazole antifungal medication that exhibits excellent activity against dermatophytes. As a topical cream and lotion (approved for human use), LCZ has demonstrated a broad spectrum of activity against human dermatophytoses. This is the first study to investigate the invitro susceptibility of clinical isolates from horse dermatophytoses to LCZ. No animals were used in this study. In the present study, the invitro susceptibilities of clinical isolates of dermatophytes to LCZ, clotrimazole (CTZ), miconazole (MCZ) and terbinafine (TRF) were investigated using the Clinical & Laboratory Standards Institute M38-A2 test. The minimum inhibitory concentrations (MICs) for all 16 clinical isolates of Trichophyton equinum, Microsporum equinum/canis and M.gypseum for LCZ were <0.03mg/L. The MICs of all isolates were <0.03-0.5mg/L for CTZ, 0.03-16mg/L for MCZ and <0.03-1mg/L for TRF. LCZ demonstrated a broad spectrum of activity against clinical isolates from horse dermatophytoses. We consider that LCZ will become the primary antifungal agent for treating horse dermatophytosis.

Effect of light exposure on growth rate of veterinary clinical dermatophyte isolates

Veterinary textbooks and literature suggest that exposure to light is inhibitory to growth of clinical dermatophyte isolates. We hypothesized that this idea was derived from experiments that examined the effect of high doses of ultraviolet and visible light exposure on dermatophyte growth, and that exposure to typical room lighting would not adversely affect dermatophyte growth rate. Isolates of common veterinary dermatophytes (three each of Microsporum canis, Nannizia gypsea and Trichophyton benhamiae) were exposed to typical fluorescent room lighting, incubated in a closed drawer, or exposed at close range to fluorescent wide-spectrum light. Dermatophytes were grown on Sabouraud Dextrose Agar (SAB) and Dermatophyte Test Medium (DTM). Colony diameter was measured and growth rate (expressed as colony diameter increase mm/day) calculated at the linear portion of the culture growth curve. Statistical analyses compared growth rates across the various incubation conditions and among dermatophyte isolates. There was little difference in growth rate between cultures incubated under typical fluorescent room lighting and those placed in the dark. Exposure to the close-range light increased growth rate as a consequence of the elevated incubation temperature created by the lamp. Significant differences in growth rate were noted among strains of the same dermatophyte species. Dermatophytes grew more rapidly on SAB than DTM agar. Exposure to typical lighting conditions in a clinical environment does not inhibit growth of dermatophyte colonies. Veterinary clinicians may conduct routine dermatophyte cultures without incubating them in the dark.