Chemical analysis and antifungal activity of the essential oil of Calea clematidea

The chemical composition of the essential oils of Calea clematidea Baker obtained by hydrodistillation of the leaves and flowers was analysed by GC and GC/MS and the oils were assayed for their antifungal activities. The essential oil of the leaves showed a high content of a new natural epoxy terpenoid, named clemateol (ca. 70 %), with minor amounts of o-vanillin (6.5 %), spathulenol (4.2 %), alpha-terpinene (4.0 %), germacrene B (2.9 %), yomogi alcohol (1.8 %), ( E)-caryophylene (1.7 %), m-cymenene (1.6 %), and alpha-gurjunene (1.5 %), while the essential oil of the flowers was characterized by a higher content of thymol methyl ether (ca. 80 %), with minor amounts of clemateol (4.8 %) and o-cymene (4.7 %). The antimicrobial activity of the oils was also evaluated against dermatophytes for their possible use in pharmaceutical preparations for topical applications. The oil of the leaves (MIC > 3.57 mg/ml), clemateol (MIC > 1.52 mg/ml), and the alcohol 2 (MIC > 2.82 mg/ml) showed a moderate antifungal activity against Trichophyton tonsurans, Trichophyton rubrum, Trichophyton menthagrophytes var. i nterdigitale, Epidermophyton floccosum, Microsporum gypseum, Microsporum canis and Microsporum nanum.

Use of the sensititre colorimetric microdilution panel for antifungal susceptibility testing of dermatophytes

The Sensititre YeastOne antifungal panel was used to test 49 dermatophytes belonging to the species Epidermophyton floccosum, Microsporum gypseum, Microsporum canis, Trichophyton tonsurans, Trichophyton rubrum, and Trichophyton mentagrophytes. The MICs of four antifungals obtained with the Sensititre YeastOne antifungal panel were compared with those obtained by the reference NCCLS microdilution method. The levels of agreement between the two methods (<or=2 dilutions) were 81.6% with amphotericin B, 87.7% with itraconazole, 67.3% with fluconazole, and 69.4% with ketoconazole.

Anti dermatophytic activity of Azardirachta indica (neem) by invitro study

The leaf and seed extracts of the Plant Azardirachta indica were tested for antidermatophytic activity against dermatophytes such as Trichophyton ruberum, Trichophyton, Mentagrophytes, Trichophyton violaceum, Microsporum nanum and Epidermophyton floccosum by tube dilution technique. The minimum Inhibitory concentration (MIC) of neem seed extract was found to be lower tan that of neem leaf when tested against different species of Dermatophytes.

Stereoselective synthesis and in vitro antifungal evaluation of (E)- and (Z)-imidazolylchromanone oxime ethers

A series of (E)- and (Z)-2, 3-dihydro-3-(1H-imidazol-1-yl)-4H-1-benzopyran-4-one oxime ethers have been synthesized and tested for antifungal activity. Most compounds showed moderate to potent in vitro antifungal activity. Among the tested compounds, compound (E)-3d was the most active agent against Candida albicans and Aspergillus niger, and compounds (Z)-(3a) and (E)-3a were the most potent compounds against Microsporum gypseum. Detailed stereoselective synthesis, spectroscopic, and biological data are reported.

Plumieride from Allamanda cathartica as an antidermatophytic agent

Plumieride has been isolated as an active principle of the leaves of Allamanda cathartica. It showed strong fungitoxicity against some dermatophytes causing dermatomycosis to animals and human beings. It exhibited a noncytotoxic nature against a P(388) mouse leukaemia cell line.

Terbinafine: efficacy and tolerability in young children with tinea capitis due to Microsporum canis

AIMS

We carried out an open, prospective, uncontrolled study to evaluate the efficacy and tolerability of terbinafine in the treatment of young children with tinea capitis due to Microsporum canis.

METHODS

A total of 83 healthy, immunocompetent children (age range 2-13 years) were enrolled in eight centres in Estonia, Latvia and Lithuania. Patients received oral terbinafine in dosages based on weight, 62.5 mg for those weighing 10-20 kg, 125 mg for 20-40 kg, plus application of topical 1% terbinafine cream twice daily to affected areas. Treatment lasted for 4 weeks, followed by an 8-week observation (treatment-free) period. All the subjects were assessed for efficacy and tolerability at 12 weeks.

RESULTS

Eighty-one subjects were available for assessment at 12 weeks: 32 had completely recovered, with no evidence of relapse during the observation period, and 21 showed mycological cure, but presented residual physical signs of infection. Thus the effective cure rate was 65.4% in an infection known to be more difficult to cure than other causes of tinea capitis. Terbinafine was well tolerated by these children.

CONCLUSIONS

This study showed effective cure of two-thirds of 81 cases of tinea capitis caused by M. canis with a 4-week course of treatment. As one-third of the cases did not respond to treatment, we suggest using combined oral and topical treatment with terbinafine in children with tinea capitis caused by M. canis.

Drug efficacy of terbinafine hydrochloride (Lamisil) during oral treatment of cats, experimentally infected with Microsporum canis

Cats represent a primary source of Microsporum canis infections in humans. Terbinafine hydrochloride (Lamisil) is commonly used in the treatment of microsporosis in humans as its fungicidal action permits short periods of treatment. The aim of the present study was to estimate the efficacy of the drug in cats. Nine cats were experimentally infected with M. canis and treated with terbinafine hydrochloride at a dose of 10-20 mg/kg (once daily, SID; low-dose group, LDG). Another nine cats were similarly infected and treated with 30-40 mg/kg SID (high-dose group, HDG) and a further nine cats were also infected and left untreated (control group, CG). The general condition of the cats was observed daily and their clinical symptoms evaluated weekly. The cats recovery was monitored using the Wood's lamp illumination test and microscopic and fungal culture examinations. The general condition of the cats during the study was good. The cure rates of the LDG were not significantly different from the CG at any period during the treatment. However, the HDG cure rates differed significantly from the other two groups. After 109 days of treatment, when all nine cats of the HDG were healed, seven cats of the LDG and all the cats in the CG were still M. canis-positive. This study shows that dosages of 10-20 mg/kg SID of terbinafine hydrochloride are not sufficient to terminate an experimental M. canis infection in cats within an acceptable period of time. Terbinafine hydrochloride can be used to treat dermatophytosis in cats, but a higher dosage, 30-40 mg/kg SID, should be used to achieve a cure.

A study of dermatophytes and their in-vitro antifungal sensitivity

Of the 150 clinically suspected cases of Dermatophytosis studied, majority of the cases were from age group 11-20 and 21-30 (51.4%), Tinea corporis (48.7%) and Tinea capitis (18%) were the commonest clinical types. The isolation rate was 24% (36) of which 19 (52.7%) were Trichophyton rubrum, 11 (30.55%) were Trichophyton mentagrophytes and 4 (11.1%) were Trichophyton violaceum. One isolate each of Microsporum gypseum & Epidermophyton floccosum were obtained. Griseofulvin proved to be the best drug with a sensitivity of 94.4% followed by Miconazole (75% sensitive). Tolnaftate showed a sensitivity of 47.22%. For Clotrimazole only 30.55% of the isolates were sensitive.

Antimicrobial activities of a new schizozygane indoline alkaloid from Schizozygia coffaeoides and the revised structure of isoschizogaline

Extracts from Schizozygia coffaeoides showed antimicrobial activity against fungal and bacterial species. Alkaloids isolated using bioassay-guided fractionation were isoschizogaline, schizogynine, and a new indoline alkaloid, 7,8-dehydro-19beta-hydroxyschizozygine, shown to be the most active antifungal compound. The structure of isoschizagaline, the only active antibacterial, is revised on the basis of NMR analysis.

In vitro susceptibility of Microsporum canis and other dermatophyte isolates from veterinary infections during therapy with terbinafine or griseofulvin

We investigated the in vitro activity of terbinafine against fresh veterinary isolates of Microsporum canis and the potential of this organism to develop resistance in vivo during oral therapy. Dermatophyte cultures (n = 300) were obtained from naturally infected cats and dogs undergoing oral therapy with terbinafine or griseofulvin. M. canis comprised 92% of isolates; other species included Microsporum gypseum and Trichophyton mentagrophytes. Minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs) of terbinafine and griseofulvin were determined by broth macrodilution assay. Terbinafine was highly active against all three species with MIC90< or =0.03 microg ml(-1), in agreement with published data. However, terbinafine exhibited primary cidal activity against 66% of Microsporum isolates (n = 275) in contrast to the almost complete cidal effect in Trichophyton (n = 18). Griseofulvin was significantly less active than terbinafine (MIC90 = 4 microg ml(-1)) but had a primary cidal action on about 40% of the isolates. The data were analysed for changes in MIC and MFC during the course of therapy, which could be indicative for development of acquired resistance. Oral treatment of 37 animals with terbinafine for up to 39 weeks caused no increase in MIC or MFC of terbinafine, either in individual patients or in the whole group.

Bioactive compounds from Iostephane heterophylla (Asteraceae)

The novel bisabolene sesquiterpenes 3-6, were isolated from Iostephane heterophylla, using bioguided fractionation. The new compounds were determined to be (12R/12S)-12,13-epoxy-xanthorrhizols (3,4) and (12R/12S)-12,13-dihydro-12,13-dihydroxy-xanthorrizols (5,6) and their structures were characterized by analysis of spectroscopic data and by chemical correlation from xanthorrhizol (2). The stereochemistry at C-12 of 5 was deduced using the modified Mosher experiment. Some of the isolated compounds elicited activity against gram positive and gram negative bacteria, levadura and dermatophytes.

Phenotypic characterization of Microsporum canis isolated from cats and dogs

To characterize strains of Microsporum canis that infect dogs and cats in São Paulo city, 30 isolates of this dermatophyte were tested for their ability to assimilate carbon and nitrogen sources, for proteinase and phospholipase secretion, for susceptibility to yeast killer toxins, and for susceptibility to the antifungals fluconazole, ketoconazole, itraconazole, 5-fluorocytosine and amphotericin B, in E test. All samples assimilated the nitrogen sources asparagine, ammonium sulphate, urea and sodium nitrate, as well as the carbon sources inulin, mannitol, trehalose, meso-erythritol, maltose, mannose, sorbitol, cellobiose, fructose and dextrin. Not all the samples assimilated adonitol, galactose, arabinose, rhamnose, raffinose, melibiose, ribose and sucrose, and none of them was capable of growing with dulcitol, lactose, or xylose as the only carbon source. Proteinase and phospholipase secretion was observed for most isolates. In the test of yeast killer toxin, 10 types could be identified, with four types exclusively observed in isolates from dogs and two types exclusively observed in isolates from cats. In the E test, all isolates were found to be resistant to the fluconazole and 5-fluorocytosine, while they were variably sensitive to amphotericin B, ketoconazole and itraconazole. When the data were submitted to the qualitative analysis in the matrix distance program FITOPAC, the similarity of the isolates could be assessed.

Antifungal principles from Piper fulvescens

Activity-guided fractionation of the dichloromethane extract from leaves of Piper fulvescens, using an agar overlay bioautographic method, led to the isolation of three antifungal neolignans identified as conocarpan, eupomatenoid 5 and eupomatenoid 6. The minimal inhibitory concentration of these three neolignans against five fungi strains were determined. Conocarpan showed the widest activity, whereas eupomatenoid 6 was the most active against dermatophytes.

Terbinafine hydrochloride treatment of Microsporum canis experimentally-induced ringworm in cats

Cats represent the most important source of Microsporum canis infection to people. Terbinafine hydrochloride is commonly used in the treatment of microsporosis. Its fungicidal action permits short period of treatment. It was our objective to evaluate the effectiveness of this drug in treatment of microsporosis in cats. We treated nine experimentally M. canis infected cats with terbinafine at a dose of 10-20mg/kg SID (low-dose group, LDG), nine cats with 30-40mg/kg SID (high-dose group, HDG), and nine cats were left untreated (control group, CG). The drug's levels in cats' plasma and hair were measured by a reversed-phase high performance liquid chromatographic method (RP-HPLC) and the cats' cure was followed by Wood's lamp illumination, microscopic exam and fungal culture. We showed no difference between the clinical course in CG and LDG, but HDG were significantly differentiated from both other groups. Terbinafine levels in plasma at 120 days of treatment were not statistically different among LDG (4.13 microg/l) and HDG (5.48 microg/l), but levels in hair of LDG (1.24 microg/l) and HDG (3.62 microg/l) were significantly different. Terbinafine can be used for the treatment of microsporosis in cats in the dose of 30-40mg/kg SID.

Pseudomycetoma caused by Microsporum canis in a Persian cat: lack of response to oral terbinafine

An eight-year-old neutered female Persian cat with a four-year history of relapsing skin disease, characterised by ulcerated nodules with a yellow granular discharge, was examined. A diagnosis of granulomatous dermatitis and panniculitis (pseudomycetoma) caused by Microsporum canis was made on the basis of history, clinical signs, histopathological examination of skin biopsy specimens and culture of macerated tissue. Because previous therapy, comprising repeated surgical excision and the administration of griseofulvin and itraconazole, had not been successful, terbinafine was administered for an eight-month period. However, lesions progressed despite this treatment and the cat was euthanased.

[Fungistatic activity of a sesquiterpene lactone (tomentosin) isolated from fresh Inula viscosa (Asteraceae) flowers from the Puglia region]

A sesquiterpene lactone, tomentosin, has been isolated and identified form Inula viscosá Ait (Asteraceae) flowers. The molecule, at 1 mg/ml concentration, showed to be active in vitro against Microsporum canis, Microsporum gypseum and Trichophyton mentagrophytes.

Expression of ubiquitin gene in Microsporum canis and Trichophyton mentagrophytes cultured with fluconazole

The expression of the ubiquitin (Ub) gene in dermatophytes was examined for its relation to resistance against the antifungal drug fluconazole. The nucleotide sequences and the deduced amino acid sequences of the Ub gene in Microsporum canis were proven to be 99% similar to those of the Ub gene in Trichophyton mentagrophytes. Expression of mRNA of Ub in M. canis and T. mentagrophytes was enhanced when the fungi were cultured with fluconazole. The antifungal activity of fluconazole against these dermatophytes was increased in the presence of Ub proteasome inhibitor.

Doubled dose of oral terbinafine is required for Microsporum canis tinea capitis

Fourteen children, ages 1-15 years, with Microsporum canis tinea capitis were given oral terbinafine for 4 weeks at the recommended daily dose according to their weight: 10-20 kg, 62.5 mg; 20-40 kg, 125 mg; > 40 kg, 250 mg. Because none of the patients had clinically responded to treatment by week 4 the dose of terbinafine was doubled (up to 250 mg) for an additional 4-8 weeks in six patients, and continued at the original dose in six patients. Two patients dropped out of the study. On final evaluation, four patients were cured after 8-12 weeks of treatment. All cured patients received the doubled dose of terbinafine, except for one who was on the usual adult dose of 250 mg from the onset. Oral terbinafine was well tolerated by all but one patient, who experienced gastrointestinal disturbance and slightly raised transaminase levels during the first 4 weeks of treatment. Terbinafine side effects were not correlated with dosage or duration of treatment. We conclude that oral terbinafine should be dosed for M. canis tinea capitis at a revised schedule according to body weight: 10-25 kg, 125 mg/day and > 25 kg, 250 mg/day. The appropriate duration of terbinafine treatment remains to be determined.

Antifungal activities of pelargonic and capric acid on Microsporum gypseum

The inhibitory effects of pelargonic and capric acid on Microsporum gypseum were examined. Solid and liquid Sabouraud glucose media containing different concentrations of pelargonic and capric acid were separately prepared and inoculated with the suspension of mycelium and spores of M. gypseum and incubated at 25 degrees C for 1 month. The culture media were examined periodically for fungal growth and the minimum inhibitory concentration (MIC) of each fatty acid was determined. The MIC for capric acid was 0.02 mg ml-1 and for pelargonic acid 0.04 mg ml-1 on solid media and 0.075 mg ml-1 for capric acid and 0.05 mg ml-1 for pelargonic acid in the liquid media.

In vitro antifungal activity of Schizozygia coffaeoides bail. (Apocynaceae) extracts

Leaf extracts of Schizozygia coffaeoides were investigated for antifungal activity using the disc diffusion assay technique. Petroleum ether 40-60 degrees C, dichloromethane-ethyl acetate (1:1) and methanol extracts were fungitoxic to Trichophyton mentagrophytes, Microsporum gypseum, Cladosporium cucumerinum and Candida albicans. The extracts were fungistatic in action.

Novel oxindole derivatives and their biological activity

The antifungal activity of fourteen novel derivatives of oxindole with side chain was studied using representatives of toxinogenic, phytopathogenic and dermatophytic filamentous fungi. Derivatives with exocyclic C=C bond in position C-3 exhibited a higher antifungal activity compared with derivatives with an exocyclic C-C bond in the same position. The strongest antifungal effects were shown by 3-(-2-thienoylmethylidene)-indol-2(3H)-ones.

A study of the efficacy of topical and systemic therapy for the treatment of feline Microsporum canis infection

Microsporum canis infection was induced in 21 healthy SPF-derived cats. Once infection was established (4 weeks after inoculation) the cats were divided into three equal groups housed in separate rooms and monitored for 16 weeks. During this time, group A cats received oral griseofulvin at approximately 50 mg/kg daily and were shampooed twice weekly with a product containing chlorhexidine and miconazole. Group B cats were treated with griseofulvin alone, and group C cats served as untreated controls. The cats were examined on a weekly basis and the severity of lesions was scored semi-quantitatively. In addition, hair samples were collected from each cat on a weekly basis by the MacKenzie brush technique and by the sticky-tape method. A semi-quantitative scoring system was also used for the assessment of fungal (M canis) growth. Generally, significant differences in clinical scores were not seen between the groups although at weeks 3, 4 and 11 there was a significant difference (P< or =0.015) with cats in group A having significantly lower median scores than those in group C. Median times to clinical resolution (return of clinical scores to zero) in groups A, B and C were at treatment weeks 2, 9 and 12, respectively (P>0.05). Median times for mycological resolution (persistently negative culture results) for groups A, B and C were at treatment weeks 2, 9 and 12, respectively, for the MacKenzie brush technique and at weeks 4, 8 and 12 for the sticky-tape technique. For both these results, the groups differed significantly (P< or =0.001) and in both instances group A had significantly more rapid resolution than groups B or C. Median culture scores were significantly different between the three groups using one or both of the sampling techniques at week 2 through to week 12 of treatment with median scores for either group A alone, or groups A and B being significantly lower than group C (P< or =0.026). These results showed a benefit from the addition of twice-weekly chlorhexidine-miconazole shampooing to systemic griseofulvin therapy alone in the treatment of M canis infected cats.

Tinea capitis dermatophytes: susceptibility to antifungal drugs tested in vitro and in vivo

BACKGROUND

Tinea capitis is a worldwide-spread infection of the scalp caused by dermatophytes and is predominantly seen in children. The clinical manifestations range from mild scaling lesions to widespread alopecia or highly inflammatory suppurating lesions. Terbinafine and itraconazole seem to be promising therapies with shorter treatment durations than griseofulvin.

OBJECTIVE

The objective of the present study was to test the sensitivity of different species of dermatophytes towards terbinafine and itraconazole, and to compare the results with a retrospective study on 35 immunocompetent patients with tinea capitis who were treated with terbinafine (Lamisil(R)).

METHODS

Minimal inhibitory concentrations (MIC) were measured with an agar dilution method.

RESULTS

Each tested species of dermatophyte was sensitive to terbinafine and itraconazole at different concentration ranges. The MIC for terbinafine ranged from 0.005 to 0.5 microg/ml and for itraconazole from 40 to 80 microg/ml. Microsporum canis was the dermatophyte least sensitive to terbinafine. Our retrospective study showed that the cure rate was excellent for Trichophyton violaceum and T. soudanense, variable for T. mentagrophytes and poor for M. canis and M. langeronii.

CONCLUSIONS

(i) Regarding the results of susceptibility tests obtained with species involved in tinea capitis, clinical efficacy is not related to MIC measured in vitro; (ii) identification of the isolated dermatophyte from tinea capitis seems to be important for choosing the appropriate treatment.

Efficacy of chlorhexidine against some strains of cultured and clinically isolated microorganisms

The efficacy of chlorhexidine digluconate was determined against some strains of collected and clinically isolated bacteria and fungi. The efficacy was evaluated either by calculating a minimum inhibitory concentration (MIC) or by efficacy trials according to the guidelines of the European Committee for Standardization. The MIC values of chlorhexidine for Staphylococcus aureus, Microsporum gypseum, Microsporum canis and Trichophyton mentagrophytes were 0.625 microg/ml, 12.5 microg/ml, 50 microg/ml and 6.25 microg/ml, respectively. The in vitro efficacy of chlorhexidine was higher against ATCC strains of S. aureus and P. aeruginosa (0.5 mg/ml for 5 min and 0.5 mg/ml for 10 min, respectively) than against clinical isolates (0.5 mg/ml for 15 min and 1 mg/ml for 10 min, respectively). The antiseptic activity of aqueous solutions of chlorhexidine against spores of Bacillus subtilis, Bacillis sfericus and Clostridium perfringens required longer contact times than against the vegetative forms. Nevertheless, 5 mg/ml of chlorhexidine in water-ethanol 20:80 v/v was totally effective against the vegetative forms or spores of these microorganisms.

[Study on the inhibitory activity, in vitro, of baicalein and baicalin against skin fungi and bacteria]

In this paper, we concentrated in examining, in vitro, the antiseptic activity of the baicalein and baicalin upon the seventeen pathogenic skin fungal and sixteen skin bacterial strains, these two flavonic compounds were known principally as the biosubstances of a traditional Chinese medicinal plant: Scutellaria baicalensis. In agar media, the baicalein possessed potent specific activity against the pathogenic yeasts with MICs of 70-100 micrograms/ml; But in the same condition, no inhibitory effect was observed upon dermatophytes and filamentous imperfect fungi for baicalein, and upon all used strains for baicalin. According to the antibacterial test of baicalein, a high efficacy was achieved against certain causative specie of axillary and foot's odour such as Micrococcus sedentarius, Staphylococcus epidermidis, S. hominis and C. xerosis with a MICs inferior to 250 micrograms/ml. The good inhibitory activity of baicalein could be linked to the group hydroxyl (-OH) in position seven of the molecule.

Inhibitors of the fungal cell wall. Synthesis of 4-aryl-4-N-arylamine-1-butenes and related compounds with inhibitory activities on beta(1-3) glucan and chitin synthases

As part of our project devoted to the search for antifungal agents, which act via a selective mode of action, we synthesized a series of new 4-aryl- or 4-alkyl-N-arylamine-1-butenes and transformed some of them into 2-substituted 4-methyl-tetrahydroquinolines and quinolines by using a novel three-step synthesis. Results obtained in agar dilution assays have shown that 4-aryl homoallylamines not possessing halogen in their structures, tetrahydroquinolines and quinolines, display a range of antifungal properties in particular against Epidermophyton floccosum and Microsporum canis. Regarding the mode of action, all active compounds showed in vitro inhibitory activities against beta(1-3) glucan-synthase and mainly against chitin-synthase. These enzymes catalyze the synthesis of beta(1-3) glucan and chitin, respectively, major polymers of the fungal cell wall. Since fungal but not mammalian cells are encased in a cell wall, its inhibition may represent a useful mode of action for these antifungal compounds.

Antifungal activity of plant extracts against dermatophytes

The aqueous extracts (15 micrograms ml-1 medium) of 22 plants used in folkloric medicine in Palestine were investigated for their antifungal activity and minimum inhibitory concentrations (MICs) against nine isolates of Microsporum canis, Trichophyton mentagrophytes and Trichophyton violaceum. The extract of the different plant species reduced colony growth of the three dermatophytes by 36 to 100% compared with the control treatment. Antimycotic activity of the extract against the three dermatophytes varied significantly (P < 0.05) between test plants. Extracts of Capparis spinosa and Juglans regia completely prevented growth of M. canis and T. violaceum. The most active extracts (90-100% inhibition) were those of Anagallis arvensis, C. spinosa, J. regia, Pistacia lentiscus and Ruta chalapensis against M. canis; Inula viscosa, J. regia and P. lentiscus against T. mentagrophytes; and Asphodelus luteus, A. arvensis, C. spinosa, Clematis cirrhosa, I. viscosa, J. regia, P. lentiscus, Plumbago europea, Ruscus aculeatus, Retema raetam and Salvia fruticosa against T. violaceum. The MICs of these most active plants ranged from 0.6 to 40 micrograms ml-1. The three dermatophytes differed significantly with regard to their susceptibility to plant extracts. Trichophyton violaceum was the most susceptible being completely inhibited by 50% of the extracts followed by M. canis and T. mentagrophytes which were completely inhibited by only 23 and 14% of the extracts, respectively.

Antifungal susceptibility testing of dermatophytes: establishing a medium for inducing conidial growth and evaluation of susceptibility of clinical isolates

A standardized reference method for dermatophyte in vitro susceptibility testing is lacking. In a previous study, Norris et al. (H. A. Norris, B. E. Elewski, and M. A. Ghannoum, J. Am. Acad. Dermatol. 40(6, part 2):S9-S13) established the optimal medium and other growth variables. However, the earlier study did not address two issues: (i) selection of an optimal medium for conidial formation by dermatophytes and (ii) validation of the method with a large number of dermatophytes. The present study addresses these two points. To select which agar medium best supported conidial growth, representative isolates of dermatophytes were grown on different agars. Preliminary experiments showed that only oatmeal cereal agar supported the production of conidia by Trichophyton rubrum. We tested the abilities of 251 T. rubrum isolates to form conidia using three different cereal agars and potato dextrose agar. Overall, oatmeal cereal and rice agar media were comparable in their abilities to support T. rubrum conidial growth. Next, we used the oatmeal cereal agar for conidial formation along with the optimal conditions for dermatophyte susceptibility testing proposed by Norris et al. and determined the antifungal susceptibilities of 217 dermatophytes to fluconazole, griseofulvin, itraconazole, and terbinafine. Relative to the other agents tested, terbinafine possessed the highest antifungal activity against all of the dermatophytes. The mean +/- standard error of the mean MICs of fluconazole, itraconazole, terbinafine, and griseofulvin were 2.07 +/- 0.29, 0.13 +/- 0.01, 0.002 +/- 0.0003, and 0.71 +/- 0.05 microgram/ml, respectively. This study is the first step in the identification of optimal conditions that could be used for the standardization of the antifungal susceptibility testing method for dermatophytes. Inter- and intralaboratory agreement as well as clinical correlations need to be established.

Overview of SPA-S-843 in vitro activity against filamentous fungi

In this study, we investigated the in vitro antifungal activity of a new water-soluble partricin A derivative, N-dimethylaminoacetyl-partricin A 2-dimethylaminoethylamide diascorbate, coded SPA-843, currently developed by Società Prodotti Antibiotici. The activity of SPA-S-843 was compared to that of amphotericin B against 13 strains of Aspergillus spp., 4 strains of Mucor sp., 4 strains of Rhizopus oryzae, 2 strains Paecilomyces variotii, 5 strains of Penicillium spp., 1 strain of Sporothrix schenkii, 7 strains of Trichophyton spp. and 2 strains of Microsporum spp.; the minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs) were measured for all the organisms. The in vitro susceptibility testing method employed was an adaptation of the macrodilution reference method for yeasts as described in the National Committee for Clinical Laboratory Standards document M27-A. The in vitro inhibitory activities of SPA-S-843 and amphotericin B against the fungi were evaluated in RPMI-1640 supplemented with L-glutamine and buffered with morpholinepropanesulfonic acid, while the in vitro fungicidal activities were determined by subculturing 0.1 ml from all tubes with no visible growth onto drug-free Sabouraud dextrose agar plates. Comparison with amphotericin B showed that the in vitro inhibitory activity of SPA-S-843 against Aspergillus spp. was better than that of amphotericin B and similar against R. oryzae, P. variotii, Penicillium spp. and S. schenkii. Amphotericin B presented geometric means (GM) of the MICs lower than those of SPA-S-843 against Mucor sp., Microsporum spp. and Trichophyton spp. SPA-S-843 was most fungicidal against Mucor sp. and P. variotii; SPA-S-843 and amphotericin B showed the same fungicidal activity against Aspergillus spp. (GM of the MFCs 12.53 microg/ml), Penicillium spp. (about 12 microg/ml) and S. schenkii (MFC 19.2 microg/ml). Amphotericin B presented GM of the MFC values lower than those of SPA-S-843 against R. oryzae, Microsporum spp. and Trichophyton spp.

The use of itraconazole to treat cutaneous fungal infections in children

BACKGROUND

Cutaneous mycoses such as tinea capitis, onychomycosis and some cases of tinea corporis/cruris, and tinea pedis/manus require oral antifungal therapy. There is relatively limited data regarding the use of the newer oral antifungal agents, e.g. itraconazole, in the treatment of these mycoses in children.

OBJECTIVE

We wished to determine the efficacy and safety of itraconazole continuous therapy in the management of cutaneous fungal infections in children.

METHODS

Children with cutaneous mycoses were treated with itraconazole in an open-label manner in 4 studies. For tinea capitis, the treatment regimens using itraconazole continuous therapy were: study 1, 3 mg/kg/day for 4 or 8 weeks; study 2, 5 mg/kg/day for 6 weeks, and study 3, 5 mg/kg/ day for 4 weeks. In a different trial, study 4, itraconazole continuous therapy 5 mg/kg/day was used to treat toenail onychomycosis (duration: 12 weeks), tinea corporis/ cruris (duration: 1 week) and tinea pedis/manus (duration: 2 weeks).

RESULTS

The efficacy rates at follow-up 12 weeks from the start of therapy in children with tinea capitis treated using the itraconazole continuous regimen were: clinical cure (CC) and mycological cure (MC) in study 1 (n = 10, Trichophyton violaceum all patients), CC 50%, MC 86%; in study 2 (n = 35, Microsporum canis 22 patients, Trichophyton sp. 12 patients), CC 82.8%, MC 80%, and in study 3 (n = 16, M. canis 11 patients, Trichophyton sp. 5 patients), (CC 66.7%, MC 78.5%. Itraconazole was also effective in the treatment of dermatomycoses in 24 children (study 4). The CC and MC rates at the follow-up 8 weeks from the start of therapy in children with dermatomycoses and 12 months in children treated for onychomycosis were: onychomycosis (n = 1, T. rubrum), CC 100%, MC 100%; tinea corporis (n = 12, M. canis 10 patients), CC 100%, MC 90%; tinea cruris (n = 3, Trichophyton sp. 2 patients), CC 100%, MC 100%; tinea manus (n = 1, T. rubrum), CC 100%, MC 100%, and tinea pedis (n = 7, T. rubrum), CC 100%, MC 100%). Adverse effects consisted of a cutaneous eruption in 1 (1.2%) of the 85 children, with mild, transient, asymptomatic elevation of liver function tests (less than twice the upper limit of normal) in 2 (3.4%) of 58 children in whom monitoring was performed.

CONCLUSIONS

Itraconazole is effective and safe in the treatment of tinea capitis and other cutaneous fungal infections in children.

[Chemical constituents of the essential oil from the fruits of Lindera glauca and its antifungal activities]

The chemical constituents of the two essential oils extracted from the fruits of Lindera glauca by hydrodistillation and petroleum ether have been studied by means of GC-MS. Among which, 32 kinds of constituents were identified in distilling oil and 22 kinds in solvent oil. The main components in distilling oil were n-carpric acid (25.39%), germacrene A (10.71%), n-dodecanole acid (10.08%), epishyobunol acetate (7.29%) and caryophyllene oxide (5.44%), and in solvent oil were camphene (17.55%), 3,6,6-trimethyl-2-norpinene (16.85%), capric acid, ethyl ester (13.61%), eucalyptol (8.10%), and alpha-cis-ocimene (7.38%), In vitro the distilling oil exhibited more manifest antifungal properties than the solvent oil with MIC between 0.03-0.5 ml/L for pathogenic fungi species and 1.0-1.5 ml/L for moulds. Almost having not contained the sesquiterpenoids and their derivatives in the solvent oil maybe were a reason of poor inhibitory.

Antimicrobial activity and stability of tingenone derivatives

Quinone-methide triterpenes of the tingenone series were evaluated for their antimicrobial activity. These compounds were effective against Bacillus cereus, B. subtilis, Sarcina lutea, Staphylococcus aureus, Microsporum gypseum and a Gram-negative bacterium, Klebsiella pneumoniae. Under acidic conditions, the quinone-methide part of these compounds rearranged into the divinyl-phenolic system, and the antimicrobial activity was thus lost.

Efficacy and safety of itraconazole pulse therapy: Brazilian multicentric study on toenail onychomycosis caused by dermatophytes

BACKGROUND

Itraconazole is a large spectrum triazole with known efficacy in both continuous and pulse therapy for various mycoses.

OBJECTIVES

Evaluate the efficacy and tolerability of itraconazole pulse therapy for onychomycosis of the toenails due to dermatophytes, in a prospective, open, non-comparative and multicentric investigation. Patients and methods The trial was completed by 72 patients of an initial total of 89. Treatment consisted of four cycles of itraconazole, 200 mg twice a day, for seven consecutive days each month. Patients were evaluated clinically, mycologically and biochemically before, during and at the end of the investigation, and were divided into two groups according to the measure of normal portion of the most affected nail (target nail), as follows: Group 1: 0-5.9 mm; and Group 2: more than 6 mm.

RESULTS

Improvement was satisfactory and progressive. Results were statistically significant, when comparing the three moments of the study: pre-treatment, end of therapy (fourth month) and follow-up (ninth month) in both groups.

CONCLUSIONS

Itraconazole pulse therapy was efficient and safe for the treatment of onychomycosis caused by dermatophytes, although a much higher daily dosage than the known continuous administration was used. Group 1, with nails initially more extensively affected, had a more evident improvement, by the mean variation in millimeters of normal portion of the target nail. This group showed a very satisfactory response, although not reaching total cure, thus demonstrating the great importance of early treatment of this disease. A residual therapeutic effect is maintained even after suspension of the drug. Group 2 obtained better total cure rates, and four pulses were, in general, sufficient, whereas more cycles would have been beneficial for the Group 1 patients with more extensive involvement.

Efficacy, safety and tolerability of terbinafine for Tinea capitis in children: Brazilian multicentric study with daily oral tablets for 1,2 and 4 weeks

BACKGROUND

Tinea capitis is a common skin disease seen predominantly in children. The standard therapies for this disease are griseofulvin and ketoconazole. Nevertheless, these drugs have drawbacks in that they are only fungistatic and require treatment for at least 6 weeks. Previous studies with oral terbinafine for the treatment of Tinea capitis have shown that this agent is effective when given for 4 weeks, comparable to an 8-week regimen with griseofulvin. To date there is no data on the use of oral terbinafine in Brazilian children.

OBJECTIVES

To assess the efficacy, safety and tolerability of oral terbinafine in short-term treatments (1-, 2- and 4-week treatment) of Tinea capitis in children.

PATIENTS AND METHODS

One hundred and thirty-two children aged 1-14 years were enrolled in this study, but only 107 were considered for the final efficacy analysis. Diagnosis included clinical assessment and examination by Wood's light. Confirmation was obtained by direct microscopy and culture for fungus. Terbinafine dosage (125 or 250 mg/day) was adjusted according to patient weight. Efficacy was evaluated both by clinical and mycological assessment. Safety and tolerability variables included data on adverse reaction and clinical laboratory evaluations.

RESULTS

Mycological evaluation in the follow-up visit at week 12 showed negative direct microscopy and culture results in 48.6, 60.5 and 69.7% patients in groups 1-, 2- and 4-week, respectively (n.s.). At week 12, 84.8% patients in group 4-week achieved clinical cure with a significant difference compared to groups 1- and 2-week, 54.3 and 60.5%, respectively (P < 0.01). Adverse reactions were present in 4.8, 6.8 and 10.9% of patients in groups 1-, 2- and 4-week, respectively. terbinafine was not associated with clinically relevant increases in liver function tests.

CONCLUSIONS

Terbinafine is an effective, well tolerated and safe antifungal agent for the treatment of Tinea capitis in children. The shorter duration of treatment resulted in lower cure rates. However, it is important to note that depending on the severity of the disease, a 1-week-only treatment can also be effective in this indication.

Griseofulvin and terbinafine in the treatment of tinea capitis in children

AIM

To compare the effectiveness of griseofulvin and terbinafine in the treatment of tinea capitis in children.

METHOD

Twenty four consecutive patients with culture proven tinea capitis were treated randomly with griseofulvin (10 mg/kg/day for 8 weeks) or terbinafine (62.5-250 mg/day for 4 weeks). Outcome was determined by absence of clinical signs, hair regrowth or negative mycology.

RESULTS

Twenty four patients (16 male, 8 female) were treated. Age ranged between 2 and 15 years (mean 4.8). Seven patients presented with kerion, the remainder with a scaling and patchy alopecia pattern of tinea capitis. The responsible organisms were Microsporum canis (17 cases) and Trichophyton verrucosum (7 cases). Fourteen children were treated with griseofulvin and 10 with terbinafine. By three months follow up, 19 patients had cleared completely with good new hair regrowth. Three children had no active disease but only minimal new hair growth. One child (griseofulvin group) had no hair regrowth but was culture negative. She had sustained significant dermal and subcutaneous skin damage requiring plastic surgery. The other (terbinafine group) had ongoing active kerion.

CONCLUSION

Both griseofulvin and terbinafine are equally effective in the treatment of tinea capitis.

Antimicrobial effects of aqueous plant extracts on the fungi Microsporum canis and Trichophyton rubrum and on three bacterial species

Aqueous extracts of 10 plants were tested for their ability to inhibit Trichophyton rubrum and Microsporum canis, the aetiological agents of dermal fungal infections in humans. These extracts were also evaluated for their activity against some bacteria. Aqueous extracts from the leaves of Inula viscosa produced detectable antifungal activity against these dermatophytes.

[Synthesis and antifungal activity of 1-(1H-1,2,4-triazole-1-yl)-2-(2,4-difluorophenyl)-3-substituted-2-propanols]

Twenty-three 1-(1H-1,2,4-triazole-1-yl)-2-(2,4-difluorophenyl)-3-substituted-2-propanols were synthesized and evaluated for antifungal activities in vitro. The synthetic methods of the intermediates are also reported. The compounds belong to two kinds: sulfones and sulfides. All of the compounds are new. The results of preliminary antifungal test showed that most of the sulfide derivatives exhibited potent activities against six kinds of common pathogenic fungi such as Microsporum lanosum, Cryptococcus neoformans, Candida albicans, Aspergillus fumigatus, Cladosporium carrionii, and Saccharomyces torulopsis in vitro. Compounds IVe, f,i,j showed equal or more potent activities when compared with ketoconazole and were markedly superior to fluconazole. The sulfone derivatives showed lower antifungal activity.

A succinylanthranilic acid ester and other bioactive constituents of Jolyna laminarioides

Methyl 2-[propanamide-2'-methoxycarbonyl] benzoate, fucosterol, trans-phytol and p-formylphenol were isolated for the first time from a methanolic extract of Jolyna laminarioides. Methyl 2-[propanamide-2'-methoxycarbonyl]-benzoate exhibited chymotrypsin inhibitory activity and also found to be active against Escherichia coli and Shigella boydii. Fucosterol exhibited antifungal activity against Curvularia lunata, Stachybotrys atra and Microsporum canis.

Itraconazole susceptibility of feline isolates of Microsporum canis

The in vitro activity of itraconazole against Microsporum canis was evaluated with 38 feline isolates. Based on the observed minimum inhibitory concentrations it can be concluded that the drug could be effective in the therapy of cats affected by M. canis ringworm.

In vitro evaluation of antifungal properties of 8.O.4'-neolignans

Eighteen racemic 8.O.4'-neolignans with six different substitution patterns in rings A and B, in their ketone and in their erythro and threo alcoholic forms, were evaluated for antifungal activity by the agar dilution method. Only the alcohols exhibited a broad spectrum of activities against Microsporum canis, Microsporum gypseum, Tricophyton mentagrophytes, Tricophyton rubrum, and Epidermophyton floccosum. (+/-)-erythro-3,4-(methylenedioxy) -7-hydroxy-1'-allyl-3',5'-dimethoxy-8.O.4'-neolignan (11) was the most active compound in the series, and E. floccosum was the most susceptible species.

[Clinical and experimental studies on composite divitriol infusion in treating tinea manum]

OBJECTIVE

To investigate the effect of Composite Divitriol Infusion (CDI) in treating tinea manum and studying its antimycotic action.

METHODS

CDI was used to treat 139 patients with tinea manum. The experimental study in vivo was done, scanning electron microscopy (SEM) was used to observe the therapeutical effect of CDI.

RESULTS

One hundred and four cases among the 139 patients were cured, 21 were markedly effective, 10 improved and 4 ineffective, the effective rate being 89.9%. Between CDI group and the control group, there was a very significant difference (chi 2 > 12.84, P < 0.005). The antimycotic action of CDI was studied in vitro. Its minimum inhibitory concentrations (MIC) of CDI were about 0.25% for Trichophyton rubrum, and 0.5% for Trichophyton gypseum and Microsporum gypseum. Trichophyton rubrum immersed with CDI show that the mycelia became roughened, deformed and macroconidum became smaller under SEM.

CONCLUSION

CDI is valuable in treating tinea manum.

An ATP bioluminescence assay applicable to rapid fluconazole susceptibility testing of dermatophytes

An ATP bioluminescence assay as a rapid reference method for fluconazole (FLCZ) susceptibility testing of dermatophytes, as well as yeasts, was developed and evaluated by comparing it with viability, turbidity and fungal protein content-based conventional methods. FLCZ susceptibility results obtained with strains of Candida albicans and dermatophytes by the bioluminescence method in high-resolution medium were well correlated with those obtained by conventional methods currently used in clinical microbiology laboratories or reported previously, including a broth dilution method by the National Committee for Clinical Laboratory Standards (NCCLS). Thus, ATP bioluminescence assay can be used to monitor fungal growth in liquid culture media. The procedure has considerable potential for the rapid testing of FLCZ susceptibility of dermatophytes and other fungi.

Human androgenic steroids affect growth of dermatophytes in vitro

Hormonal effects on fungal growth are of particular interest to medical mycology. In the skin, androgenic steroids metabolized within pilosebaceous units may have direct effects on dermatophytes that invade hair follicles. In this study, 10(-1) to 10(2) mg 1(-1) testosterone, 5-alpha-dihydrotestosterone, dehydroepiandrosterone, androstenedione and androstanedione were used in agar dilution assays to test their effects on thallus diameters of Trichophyton rubrum, Epidermophyton floccosum, T. tonsurans, T. mentagrophytes and Microsporum canis. All dermatophytes responded in a dose-dependent manner with reduced diameters of thalli. Growth of T. rubrum and E. floccosum was completely or strongly suppressed by 10(2) mg 1(-1) androstenedione and androstanedione. A minor inhibition of all strains was obtained with 10(1) to 10(2) mg 1(-1) testosterone, dehydroepiandrosterone and 5-alpha-dihydrotestosterone, the last being least inhibitory for all species. Trichophyton mentagrophytes and M. canis were least responsive to most hormones. The high susceptibility of T. rubrum and E. floccosum to intrafollicular androstenedione and androstanedione could be one reason why these two species are unable to cause tinea capitis. Receptor-mediated effects and an unspecific interference with fungal sterol metabolism are discussed as mechanisms of fungal inhibition by steroidal hormones.

Effect of glucose and thiamine concentrations on the formation of macroconidia in dermatophytes. Occurrence of dysgonic Microsporum canis strains in Athens, Greece

Data collected from multiple trials with 110 fresh and preserved clinical isolates of Trichophyton mentagrophytes var. mentagrophytes, T. violaceum, T. rubrum, T. verrucosum, Microsporum canis and Epidermophyton floccosum revealed that production of macroconidia depends on glucose and thiamine concentrations in the medium. Optimal macroconidia production was obtained at the critical concentrations of 5 g l-1 glucose and 0.6 g l-1 thiamine when the two compounds were used in combination. The same conditions also encouraged macroconidia production in aconidial strains of T. verrucosum. Cutaneous inoculation in immunocompetent laboratory rabbits further enhanced the macroconidia producing capacity of the tested strains. Emphasis was placed on the occurrence of dysgonic/atypical strains of M. canis, which readily reverted to their typical phenotypes after growth on medium supplemented with 0.6 g l-1 thiamine, a process greatly augmented after cutaneous animal inoculation. It was verified that selective exogenous factors affect macroconidial production and that the dysgonic group of M. canis constitutes an epidemiologically significant group in the Greater Athens area. This is the first report of the occurrence of such M. canis strains from Greece.

In vitro susceptibility of fungi to acyclic inhibitors of 2,3-oxidosqualene cyclases

In the present study we determine the antifungal properties of two acyclic inhibitors of 2,3-oxidosqualene cyclases: 22,23-epoxy-2-aza-2,3-dihydrosqualene (EAS) and azasqualene alcohol (ASA). Fungistatic and fungicidal activity towards dermatophytes and other fungi involved in cutaneous and systemic infections was tested (48 isolates from 10 species). The tests were carried out by inoculating 10 microliters of mycelial homogenate in 1 ml of Sabouraud glucose liquid medium containing serial dilutions of 100 to 0.25 micrograms ml-1 of the substance. For each isolate, the minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC) of both compounds were determined. EAS was more active (MIC range 1.5-25 micrograms ml-1) than ASA (MIC range 3-50 micrograms ml-1). At the highest concentration tested, EAS also showed fungicidal action towards some isolates of Trichophyton mentagrophytes, T. terrestre, Epidermophyton floccosum, Microsporum canis and Scopulariopsis brumptii. The most sensitive species was T. mentagrophytes, the most resistant T. rubrum.

Evaluation of the susceptibility of dermatophytes to antifungal drugs: a new technique

The evaluation of the minimal inhibitory concentration (MIC) for pathogenic fungi is still a technically difficult assay. Insufficient standardization of the technique is often the basis of problems which appear. Culture characteristic of dermatophytes do not favour techniques usually used in bacteriology (Steers agar dilution method). A study was undertaken to compare the Steers agar dilution method and a new culture method to evaluate the minimal inhibitory concentration of antifungal compounds on several species of dermatophytes. The new method involves dilution of the antifungal drug in solid medium in a Petri dish. Standardized agar cylinders are cut from the plates and filled with inocula of the same size cut from plates of dermatophyte cultures. Such inocula facilitate analysis of the fungus in its natural growth conditions in vitro without being submitted to a disruptive preparative technique. The MIC values were similar for the two methods of evaluation in spite of important differences between the inocula. The new technique is reliable, quick, and highly reproducible. It is more efficient than the Steers agar dilution method because it enables assays to be run on several strains simultaneously and avoids labour-intensive procedures for the preparation of the inocula.