Growth Of Dermatophytes Research Articles

Synthesis of Some New Monocyclic β-Lactams Bearing a Morpholine Moiety at their N1 Positions as Antifungal Agents

The synthesis of 40 new monocyclic β-lactams bearing a morpholine moiety at their N1 positions is described. The structures of these compounds have been confirmed by IR, 1H-NMR, 13C-NMR, Mass spectra and Elemental analysis. The antimicrobial activities of the synthetic compounds have been tested against clinically important fungi including Candida, Aspergillus and Microsporum and Epidermophyton species by broth microdilution method as recommended by CLSI. Inhibition studies showed that some of the tested compounds, in particular those with phenoxy groups, exhibited strong antifungal activities against all tested fungi at concentrations of less than 8 μg/mL, while others only inhibited the growth of dermatophytes or Aspergillus species. These results suggest that the derivatives should be investigated further for possible use in antimicrobial products. Keywords: Antifungal, aspergillus, azetidine-2-one, candida, dermatophyte, fungi, monocyclic β-lactam, morpholine.

Two Antifungal Components Isolated from Fructus Psoraleae and Folium Eucalypti Globuli by Bioassay-Guided Purification

Fructus Psoraleae and Folium Eucalypti Globuli have long been used as Chinese medicines to treat various ailments such as asthma, eczema and dermatomycosis. In previous studies, their antifungal activities were demonstrated. The aim of the present study was to isolate active antidermatophytic compounds from their ethanolic extracts by means of bioassay-guided purification. Guided by the inhibitory activities on Trichophyton mentagrophytes, Trichophyton rubrum and Paecilomyces variotii, bakuchiol was isolated from the n-hexane fraction of Fructus Psoraleae whilst macrocarpal C was isolated from the n-hexane fraction of Folium Eucalypti Globuli. Both pure compounds could effectively inhibit the growth of dermatophytes in vitro. This is the first paper to report the isolation and identification of active antidermatophytic compounds from Fructus Psoraleae and Folium Eucalypti Globuli by the bioassay-guided purification.

Elevation of antidermatophytic action of mefenamic acid by cobalt ions

Objectives:To evaluate the antifungal property of mefenamic acid, which is a member of non-steroidal anti-inflammatory drugs (NSAIDs) group.Materials and Methods:In order to evaluate the antifungal property of mefenamic acid on dermatophytes, it was mixed with cobalt (Co) in culture media. Two species related to two genera of dermatophytes were tested for their susceptibility to mefenamic acid and its complex with Co by using colony diameter measurement method.Results:The inhibitory action of mefenamic acid on fungal strains was increased in the presence of Co. Epidermophyton floccosum showed more susceptibly to either mefenamic acid or its complex with Co than Trichophyton mentagrophytes variant mentagrophytes.Conclusions:Mefenamic acid showed potential ability to prevent growth of dermatophytes. This ability increased due to the presence of Co.

Bioactive Chemical Constituents and Comparative Antimicrobial Activity of Callus Culture and Adult Plant Extracts from Alternanthera tenella

Crude extracts of a callus culture (two culture media) and adult plants (two collections) from Alternanthera tenella Colla (Amaranthaceae) were evaluated for their antibacterial and antifungal activity, in order to investigate the maintenance of antimicrobial activity of the extracts obtained from plants in vivo and in vitro. The antibacterial and antifungal activity was determined against thirty strains of microorganisms including Gram-positive and Gram-negative bacteria, yeasts and dermatophytes. Ethanolic and hexanic extracts of adult plants collected during the same period of the years 1997 and 2002 [Ribeirão Preto (SP), collections 1 and 2] and obtained from plant cell callus culture in two different hormonal media (AtT43 and AtT11) inhibited the growth of bacteria, yeasts and dermatophytes with inhibition halos between 6 and 20 mm. For the crude extracts of adult plants bioassay-guided fractionation, purification, and isolation were performed by chromatographic methods, and the structures of the isolated compounds were established by analysis of chemical and spectral evidences (UV, IR, NMR and ES-MS). Steroids, saponins and flavonoids (aglycones and C-glycosides) were isolated. The minimum inhibitory concentration (MIC) of the isolated compounds varied from 50 to 500 microg/mL.

Cochrane review: Systemic antifungal therapy for tinea capitis in children

AbstractBackgroundTinea capitis is a common contagious fungal infection of the scalp in children. Systemic therapy is required for treatment and to prevent spread.ObjectivesTo assess the effects of systemic anti‐fungal drugs for tinea capitis in children.Search strategyWe searched the Cochrane Skin Group Specialised Register (June 2005), the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 2, 2005), MEDLINE (2003 to June 2005), EMBASE ( 2003 to June 2005), LILACS (1982 to July 2005), CINAHL (1982 to July 2005), the ACP journal club (1991 to July 2005) and Healthstar (1975 to July 2005).Selection criteriaRandomised controlled trials (RCTs) that evaluated systemic antifungal therapy in people with normal immunity under the age of 18 who had tinea capitis confirmed by microscopy or growth of dermatophytes in culture or both.Data collection and analysisAt least two authors independently examined each retrieved trial for eligibility and quality.Main resultsWe included 21 studies (1812 participants).Infections involving Trichophyton species: Terbinafine for 4 weeks and griseofulvin for 8 weeks showed similar efficacy in 3 studies involving 382 participants (RR 1.09; 95% CI 0.95 to 1.26). Cure rates following treatment with itraconazole and griseofulvin for 6 weeks were similar in 1 study of 35 children (RR 1.06; 95% CI 0.81 to 1.39). Another study of 100 children did not show any significant difference in cure between itraconazole for 2 weeks compared with griseofulvin for 6 weeks (RR 0.89; 95% CI 0.76 to 1.04). There was no difference between itraconazole and terbinafine for treatment periods lasting 2 to 3 weeks in 2 studies involving 160 children (RR 0.93; 95% CI 0.72 to 1.19). Two studies that included 140 children found similar cure rates between 2 to 4 weeks of fluconazole with 6 weeks of griseofulvin (RR 0.92; 95% CI 0.80 to 1.05).Microsporum infections: There was no significant difference in cure between terbinafine and griseofulvin in children with Microsporum infections in 1 small study of 29 children (RR 0.64; 95% CI 0.19 to 2.20).Authors' conclusionsThe best evidence suggests that newer treatments including terbinafine, itraconazole and fluconazole may be similar to griseofulvin in children with tinea capitis caused by Trichophyton species. Newer treatments may be preferred because shorter treatment durations may improve treatment adherence, although they may be more expensive. There is not enough evidence on the use of systemic treatments in children with Microsporum infections. Not all treatments for tinea capitis are available in paediatric formulations but all have reasonable safety profiles.Plain language summarySystemic antifungal therapy for tinea capitis (also known as ringworm) in children.Tinea capitis is a fungal infection of the scalp caused by two main species called Trichophyton and Microsporum. It is common in children. Systemic therapy is generally required to cure the problem, and several systemic anti‐fungal agents are available. The best evidence suggests that newer treatments such as terbinafine, itraconazole and fluconazole are probably as good as griseofulvin in children with tinea capitis caused by Trichophyton infections. Newer treatments may be preferred because they can be given for shorter treatment durations which may in turn improve adherence to treatment. However, they may be more expensive. There is still not enough evidence on the use of treatments in children with Microsporum infections. Not all treatments for tinea capitis are available in syrup formulations but all appear to be reasonably safe.

Selection of Natural Strains of Fungal Endophytes from Azadirachta indica A. Juss, with Anti-Microbial Activity Against Dermatophytes

Increasing drug resistance among bacteria, fungi and other pathogenic microbes and the remarkable increase in the incidence of fungal infections like dermatomycoses in the world population underscore our inadequacy to deal with them. Thus there is an urgent need to search chemically novel, natural, renewable and safe anti-microbial substances that can offer opportunity for innovation of new drugs to combat the widespread dermatomycoses. Six fungal endophytic strains (Scytalidium sp. MCPL AzF 023, Pestalotiopsis sp. MCPL AzB 153, Colletotrichum sp. MCPL AzR 249, Alternaria sp. MCPL AzL 198, Nigrospora sp. MCPL AzS 076, and Chloridium sp. MCPL AzR 142) from Azadirachta indica A Juss were screened and evaluated their efficacy against dermatophytes Trichophyton and Microsporum. The susceptibility test was performed by whole plate diffusion method. The EtOAc extracted Scytalidium, Chloroform extracted Nigrospora, Colletotrichum, and Alternaria, ethyl ether extracted Nigrospora in particular significantly reduced the growth of dermatophytes. The MIC ranged from 125-400 μg ml-1 for Trichophyton and 200-350 μg ml-1 for Microsporum while the MFC ranged from 230 to 425 μg ml-1. The chloroform, EtOAc, and ethyl ether were the solvents that might dissolve major active fractions of Pestalotiopsis, Scytalidium and Chloridium. The growth patterns of dermatophytes were also significantly distorted at concentration of 100 μg ml-1 (below MIC), which is statistically significant with reference to untreated fungi. In this study, we recovered bioactive fractions that might be chemically novel and effective against dermatophytes particularly and on other human and plant pathogens in general. Thus we might anticipate some new bioactive compounds to design new effective drugs against dermatomycoses initially.

Screening of chemical composition, antimicrobial and antioxidant activities of Artemisia essential oils

The chemical composition of essential oils isolated from aerial parts of seven wild sages from Western Canada – Artemisia absinthium L., Artemisia biennis Willd., Artemisia cana Pursh, Artemisia dracunculus L., Artemisia frigida Willd., Artemisia longifolia Nutt. and Artemisia ludoviciana Nutt., was investigated by GC–MS. A total of 110 components were identified accounting for 71.0–98.8% of the oil composition. High contents of 1,8-cineole (21.5–27.6%) and camphor (15.9–37.3%) were found in Artemisia cana, A. frigida, A. longifolia and A. ludoviciana oils. The oil of A. ludoviciana was also characterized by a high content of oxygenated sesquiterpenes with a 5-ethenyltetrahydro-5-methyl-2-furanyl moiety, of which davanone (11.5%) was the main component identified. A. absinthium oil was characterized by high amounts of myrcene (10.8%), trans-thujone (10.1%) and trans-sabinyl acetate (26.4%). A. biennis yielded an oil rich in ( Z)-beta-ocimene (34.7%), ( E)-beta-farnesene (40.0%) and the acetylenes (11.0%) ( Z)- and ( E)-en-yn-dicycloethers. A. dracunculus oil contained predominantly phenylpropanoids such as methyl chavicol (16.2%) and methyl eugenol (35.8%). Artemisia oils had inhibitory effects on the growth of bacteria ( Escherichia coli, Staphylococcus aureus, and Staphylococcus epidermidis), yeasts ( Candida albicans, Cryptococcus neoformans), dermatophytes ( Trichophyton rubrum, Microsporum canis, and Microsporum gypseum), Fonsecaea pedrosoi and Aspergillus niger. A. biennis oil was the most active against dermatophytes, Cryptococcus neoformans, Fonsecaea pedrosoi and Aspergillus niger, and A. absinthium oil the most active against Staphylococcus strains. In addition, antioxidant (beta-carotene/linoleate model) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities were determined, and weak activities were found for these oils.

In vitro methods for antifungal susceptibility testing of Trichophyton spp.

In general, methods to test the susceptibility of fungi to antifungal drugs require standardized techniques, but so far there is no methodology that is widely applicable to dermatophytes. Here we introduced modifications to the protocols from documents of the National Committee for Clinical Laboratory Standards (CLSI) M38-A and the Antifungal Susceptibility Testing Subcommittee of the European Committee on Antimicrobial Susceptibility Testing (EUCAST) that are usually applied to moulds and fermentative yeasts, in order to adjust the conditions for the growth of dermatophytes. The modifications included: growth on potato dextrose agar supplemented with 2 % in-house rice flour to encourage sporulation, the addition of 2 % glucose to the culture media (RPMI-1640), and an incubation temperature of 28 °C. In addition, the incubation period was 7 d, the minimum inhibitory concentration (MIC) was defined as 80 % growth inhibition endpoints for azole agents, and the inocula only contained microconidia. Results obtained by both tested methodologies were very similar to the ones reported by other researchers. MIC 90 (MIC at which 90% of isolates tested were inhibited) values were identical for four out of five antifungal drugs tested and there was only a difference of one or two dilutions when MIC 50 values were compared. Although the modifications introduced did not interfere with the results, more studies are necessary to establish a standard technique to test susceptibility of dermatophytes to antifungal drugs.

Antimicrobial and antioxidant activities of the methanolic extracts of three Salvia species from Tunisia

This study examines the in vitro antimicrobial and antioxidant activities of the methanolic extracts of three Salvia species from Tunisia: Salvia aegyptiaca L., S. argentea L. and S. verbenaca Ssp. clandestina L. Pugsley. The extracts inhibited the growth of dermatophytes and of bacteria responsible for unpleasant odours to varying degrees; the pathogenic yeasts Candida albicans and Cryptococcus neoformans, the filamentous fungi Aspergillus fumigatus and selected dog otitis bacteria were all resistant to each of the extracts. The extracts were screened for their antioxidant activities using 2,2-diphenyl-1-picrylhydrazyl free radical scavenging and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) test systems, and gave positive results in both tests. The extracts of S. aegyptiaca were the most active in both tests, followed by those of S. verbenaca, then S. argentea. These results confirm the antimicrobial and antioxidant activities of the genus Salvia and underline the potential of these plants either as natural preservatives or in pharmaceutical applications.

Ocorrência de dermatófitos em amostras de unhas, pés e mãos coletadas de estudantes universitários

The objective of this paper was to evaluate the occurrence of dermatophytes, specifically in the nails, feet and hands of university students with and without lesions. Two hundred and eighty samples were collected; 31 (11.1%) were positive by direct examination, while only 20 (7.1%) showed dermatophyte growth in culture, as well as direct positive examination. Trichophyton rubrum was the most frequently isolated (80%) dermatophyte followed by T. mentagrophytes (20%). Considering the sites analyzed, dermatophyte occurrence was: 10.4% in toenails, 5% in foot skin, 2.5% in fingernails and 0.4% in hand skin.

In vitro and in vivo Effects of Lufenuron on Dermatophytes Isolated from Cases of Canine and Feline Dermatophytoses*

Lufenuron is a benzyl-urea phenol compound that inhibits chitin synthesis and is used as an insecticide. Its efficacy in the therapy of dermatophytosis in dogs and cats was evaluated in several clinical studies, with contradictory results. We assessed the in vitro susceptibility of dermatophytes isolated from dogs and cats to lufenuron, and the clinical response of skin lesions to the drug. Dermatophyte cultures isolated from clinical cases were exposed to lufenuron by three different methods: direct application and application of whole blood or subcutaneous tissue samples obtained from a lufenuron-treated healthy dog. No inhibition of dermatophyte growth was observed in any of the samples after 1 week of incubation. Eight dogs and six cats with skin lesions were included in the in vivo survey. Results indicated that six of seven skin lesions that were diagnosed as being caused by dermatophytes did not respond to lufenuron whereas six of seven skin lesions that were not caused by dermatophytes improved. We concluded that lufenuron, in the way it was administered in this study, had no inhibitory activity on dermatophytes in vitro or in vivo and its clinical use as an anti-fungal agent is questionable. An immunomodulatory effect of the drug is, however, possible.

The Effect of Dimethyl Sulfoxide (DMSO) on the Growth of Dermatophytes

Dimethyl sulfoxide(DMSO) is frequently used as a solvent for antifungal drugs in various studies to determine their MICs. Reports on comparative evaluation of methods for the susceptibility testing of antifungal drugs have shown there is poor agreement among methods. Besides other factors which could cause variability in the results, one important factor might be the effect of DMSO on the growth of fungi. The effect of DMSO on the growth of some species of Candida has been reported in the literature. The present study aimed at determination of the effect of different concentrations of DMSO (0.125 to 10%) on the growth of dermatophytes by agar diffusion method. There was no growth of fungi in 10% DMSO, between 1.25 and 5% there was a rather linear dose-related inhibitory effect on the growth, significantly different from the controls, and below 1% there was a variable effect among the species. DMSO down to 0.25% significantly inhibited the growth of most strains of M. canis. The lower concentrations of DMSO, which apparently do not affect the growth of fungi, may potentiate the effect of antifungal drugs.

Role of Chrysosporium keratinophillum in the parasitic evolution of dermatophytes

Anti-dermatophytic activity of Chrysosporium keratinophillum against species of the genera Trichophyton, Microsporum and Epidermophyton floccosum was tested in vitro. When C. keratinophillum and different species of dermatophytes were inoculated on Sabouraud's dextrose agar plates 2 cm apart, no antagonistic effect of C. keratinophillum on the mycelial growth of dermatophytes was observed. However, conidia production was not observed on the hyphae of Trichophyton rubrum, Trichophyton tonsurans and E. floccosum grown near C. keratinophillum. The secretory substances released by C. keratinophillum inhibited the growth of T. rubrum, T. tonsurans, Trichophyton mentagrophytes var. interdigitale and E. floccosum at a concentration of 2,000 microg ml(-1) when tested by broth dilution technique. No inhibition of the growth was observed for Microsporum gypseum and Microsporum nanum. The anti-fungal activity of secretory substances released by C. keratinophillum was recorded to be heat stable. Results of the present study suggest that the anti-dermatophytic activity of the secretory substances of C. keratinophillum on T. rubrum, T. mentagrophytes var. interdigitale, T. tonsurans and E. floccosum may be responsible in part, for the absence of these dermatophyte species in soil. Considering the global prevalence of C. keratinophillum in soil one may speculate that the anti-dermatophytic activity of C. keratinophillum is one of the early events for the evolutionary divergence of saprophytic archi-dermatophytes to obligate parasitic dermatophyte species.

Review: oral antifungal drugs promote cure of fungal infections of the foot

; Bell-Syer SE, Hart R, Crawford F, et al. Oral treatments for fungal infections of the skin of the foot. Cochrane Database Syst Rev 2002;(2):CD003584 (latest version 5 Dec 2001)....

Efficacy of pre‐treatment with lufenuron for the prevention of Microsporum canis infection in a feline cohabitant‐challenge model

We previously observed a trend towards clinically milder or delayed Microsporum canis infections in cats pre‐treated with lufenuron, suggesting a possible effect of this drug in limiting dermatophyte growth. We sought to determine the effect of pre‐treatment with lufenuron on development of M. canis infections induced via exposure to an infected cat. Lufenuron suspension (100 to 140 mg kg−1 orally, once monthly; or 40 mg subcutaneously, every 6 months) or placebo was administered to groups of eight juvenile cats. After 4 months of treatment, cats were challenged by introducing cats with mild, experimentally induced M. canis infections into the rooms. The extent of any resulting infection was monitored for 22 weeks after challenge. All cats became infected with M. canis. Cats treated with lufenuron had significantly lower infection scores during the early weeks following exposure, and there was a more prolonged initial progression phase of the infection. Once infections reached peak intensity, they resolved over a similar time period in both treated and control groups. We conclude that lufenuron, when used at the dose schedule and under the conditions in this study, did not prevent dermatophyte infection by exposure to an experimentally infected cat. The delay in establishment of infection may reflect an inhibitory effect of lufenuron on the organism that is measurable, but not sufficient to prevent development of infection under these conditions. This study was supported by Novartis Animal Health.

Oral treatments for fungal infections of the skin of the foot.

About 15% of the world population have fungal infections of the feet (tinea pedis or athlete's foot). There are many clinical presentations of tinea pedis, and most commonly, tinea pedis is seen between the toes (interdigital) and on the soles, heels, and sides of the foot (plantar). Plantar tinea pedis is known as moccasin foot. Once acquired, the infection can spread to other sites including the nails, which can be a source of re-infection. Oral therapy is usually used for chronic conditions or when topical treatment has failed. To assess the effects of oral treatments for fungal infections of the skin of the foot (tinea pedis). For this update we searched the following databases to July 2012: the Cochrane Skin Group Specialized Register, CENTRAL in The Cochrane Library, MEDLINE (from 1946), EMBASE (from 1974), and CINAHL (from 1981). We checked the bibliographies of retrieved trials for further references to relevant trials, and we searched online trials registers. Randomized controlled trials of oral treatments in participants who have a clinically diagnosed tinea pedis, confirmed by microscopy and growth of dermatophytes (fungi) in culture. Two review authors independently undertook study selection, "Risk of bias" assessment, and data extraction. We included 15 trials, involving 1,438 participants. The 2 trials (71 participants) comparing terbinafine and griseofulvin produced a pooled risk ratio (RR) of 2.26 (95% confidence interval (CI) 1.49 to 3.44) in favors of terbinafine's ability to cure infection. No significant difference was detected between terbinafine and itraconazole, fluconazole and itraconazole, fluconazole and ketoconazole, or between griseofulvin and ketoconazole, although the trials were generally small. Two trials showed that terbinafine and itraconazole were effective compared with placebo: terbinafine (31 participants, RR 24.54, 95%CI 1.57 to 384.32) and itraconazole (72 participants, RR 6.67, 95%CI 2.17 to 20.48). All drugs reported adverse effects, with gastrointestinal effects most commonly reported. Ten of the trials were published over 15 years ago, and this is reflected by the poor reporting of information from which to make a clear "Risk of bias" assessment. Only one trial was at low risk of bias overall. The majority of the remaining trials were judged as "unclear" risk of bias because of the lack of clear statements with respect to methods of generating the randomization sequence and allocation concealment. More trials achieved blinding of participants and personnel than blinding of the outcome assessors, which was again poorly reported. The evidence suggests that terbinafine is more effective than griseofulvin; and terbinafine and itraconazole are more effective than no treatment. In order to produce more reliable data , a rigorous evaluation of different drug therapies needs to be undertaken with larger sample sizes to ensure they are large enough to show any real difference when two treatments are being compared. It is also important to continue to follow up and collect data , preferably for six months after the end of the intervention period, to establish whether or not the infection recurred.

Euclidean and Fractal Computer-Assisted Corneofungimetry: A Comparison of 2% Ketoconazole and 1% Terbinafine Topical Formulations

Background: The corneofungimetry bioassay was designed as a unique model predicting the efficacy of topical and oral antifungals in dermatomycoses. Objective: In this 2-step study performed in two groups of 15 volunteers, corneofungimetry was used to compare the effect of 5-day b.i.d. treatments with 2% ketoconazole and 1% terbinafine creams. Methods: The bioassay was performed using 10 isolates of each of the 3 fungi Trichophyton rubrum, T. mentagrophytes var. interdigitale and Candida albicans put to grow on human stratum corneum. Controls were stratum corneum either untreated or enriched in propylene glycol contained in an unmedicated vehicle. Quantitative assessments were made using both Euclidean and fractal geometry parameters. Results: In comparison with untreated stratum corneum, the fungitoxic activity of the 2% ketoconazole and 1% terbinafine formulations was obvious and similar against dermatophytes. By contrast, 2% ketoconazole was significantly more active against C. albicans than 1% terbinafine. The propylene-glycol-containing vehicle did not exhibit a significant effect upon the dermatophyte growth. Positive linear correlations were yielded between the extent area and the fractal dimension D of dermatophyte mycelia. By contrast, D appeared unrelated to the relative area of dermatophyte growth compared to controls. Conclusion: The combination of Euclidean and fractal analyses improves the information provided by the corneofungimetry bioassay. Creams containing 2% ketoconazole and 1% terbinafine appear equally effective against dermatophytes while the former is more potent against Candida albicans.

Fluorescent method for studying the morphogenesis and viability of dermatophyte cells.

The dermatophyte Microsporum canis is commonly isolated from human and animal infection. The morphogenesis of this fungus was studied during its developmental stages through the fluorescent method Fluorescein Diacetate and Ethidium Bromide. To this end, 50 microl dermatophyte suspension were transferred onto cellophane wrapping esterilized discs (2.5 cm of diameter) placed over the surface of Sabouraud dextrose agar on Petri dishes and incubated at 25 degrees C for 30 days. Every 60 minutes during the first 24 hours and every 12 hours for next 29 days, one disc was transferred onto glass slide, covered with equal volumes of freshly prepared fluorescein diacetate (FDA) and ethidium bromide (EB) solution, mounted with a coverslip and incubated in the dark for 30 minutes, at 25 degrees C. Each preparation was then examined on a fluorescent microscope. M. canis presented well defined growth stages: (1) tumescence of cells; (2) germination; (3) development of hyphae; (4) production of conidia and (5) tumescence and formation of arthroconidiae. Using the fluorescent method, non viable cells showed a light bright red coloration and viable cells presented green fluorescence. The principal morphological changes have occurred between the 3rd until the 18th day of culture. The method is very useful to demonstrate the dermatophyte growth stages as well as the perfect differentiation between viable and non viable cells.

Antimicrobial effect of resveratrol on dermatophytes and bacterial pathogens of the skin

The phytoalexin resveratrol is commonly found in food and drinks, including red wine, grapes, and peanuts. Many studies have shown that this compound has anti-inflammatory properties, and it has been ascribed as having health benefits that help to prevent cancer and coronary heart disease. A treatment that combines antimicrobial and anti-inflammatory actions may be desirable for alleviating many skin conditions that range in severity. Therefore, we evaluated the antimicrobial activity of resveratrol against bacteria and dermatophytes that are major etiologic agents of human skin infections. Using the broth microdilution protocol of the National Committee for Clinical Laboratory Standards (NCCLS) M7-A5, growth of the bacterial species Staphylococcus aureus, Enterococcus faecalis, and Pseudomonas aeruginosa was inhibited at 171–342 μg/mL of resveratrol in the solvent dimethyl sulfoxide. Using the NCCLS protocol M38-P, activity against the fungal species Trichophyton mentagrophytes, Trichophyton tonsurans, Trichophyton rubrum, Epidermophyton floccosum, and Microsporum gypseum was also tested. The growth of dermatophytes was inhibited at 25–50 μg/mL of resveratrol. Thus, this study indicates a novel application for resveratrol, a molecule of plant defense, to combat human fungal pathogens. Resveratrol and its analogs may have wide application to skin conditions that afflict a significant portion of our population, and may also have promising clinical potentials in diabetic wounds.

Dermatophytes and saprobe fungi isolated from dogs and cats in the city of Fortaleza, Brazil

The possible involvement of saprobe fungi in dermatomycoses, as well as the determination of the incidence of dermatophytes in dogs and cats were studied. During a period of one year, 74 dogs and 18 cats, with cutaneous lesions suggesting mycoses were included in this study. The mycological analyses were conducted by direct microscopy and by fungal culture on Sabouraud agar, chloramphenicol Sabouraud agar and mycosel agar. Of the 92 samples, 21 resulted in positive cultures for dermatophytes. Dermatophyte fungi pure cultures were obtained from 13 samples. A simultaneous growth of dermatophytes plus saprobe fungi was observed in 8 of the samples. Of the remaining 71 samples, no fungal growth was observed in 10 samples, and at minimum the growth of one saprobe fungi in 61. One, two and three genera of saprobe fungi were isolated in 29, 30 and 2 samples, respectively. Microsporum canis was isolated in 6 (28.6 %) and 10 samples (47.6 %) from cats and dogs, respectively, and Trichophyton mentagrophytes in 2 (9.5 %) and 3 samples (14.3 %) from cats and dogs, respectively. The following genera of saprobe fungi were also isolated: Alternaria sp (1.9%), Chaetomium sp (1.9%), Rhizopus sp (2.9%), Curvularia sp (3.9%), Candida sp (6.8%), Trichoderma sp (6.8%), Fusarium sp (7.8%), Cladosporium sp (8.7%), Penicillium sp (21.4%) and Aspergillus sp (37.9%).