Scanning and transmission electron microscopy: study of effects of econazole on Microsporum canis

Microsporum canis is a frequent dermatophyte in France, and causes tinea and herpes circinatus in children. This work shows the superficial and ultrastructural alterations induced by Econazole nitrate on this fungus.

[In vitro action of a new antifungal agent, naftifine, on dermatophytes]

Naftifine is a new antifungal agent derived from naphtalenemethane amine and highly active in vitro against dermatophytes. We studied this action against more than 100 strains belonging to 16 different species of the Trichophyton, Microsporum and Epidermophyton genera. MICs were determined in a liquid or solid medium using YMA and YMB Sabouraud broths. Yeasts (Candida, Torulopsis) and certain molds such as Scopulariopsis brevicaulis showed little susceptibility. In contrast, MICs for dermatophytes ranged from 0.01 to 0.2 microgram/ml on agar (YMA Sabouraud) and from 0.2 to 2 microgram/ml in broth (YMB Sabouraud). These values are lower than those obtained under similar conditions with imidazoles and equivalent to those obtained with tolnaflate or griseofulvin.

[Disinfection for dermatomycoses in veterinary practice]

Sporulating cultures of two strains of Trichophyton equinum, two strains of Trich. mentagrophytes and one strain of Microsporum canis were tested by a simple dipping technique for their sensitivity to ten currently used disinfectants. Antifungal effects on all cultures of dermatophytes were observed already after one-minute treatment with 0.5%-4% peracetic acid, 4% formaldehyde solution and concentrated solution of Lastanox super. The above strains were inactivated after five-minute treatment with 1% and 2% formaldehyde solution, 20% Iodonal B solution and Ajatin solution with 10% active substance. Fungistatic effects of various intensity were observed in the other disinfectants.

Antimycotic azoles. 7. Synthesis and antifungal properties of a series of novel triazol-3-ones

A series of novel triazol-3-ones have been synthesized, and their in vitro and in vivo antifungal properties are reported. Compound 68 (itraconazole), which displays a pronounced oral activity against vaginal candidosis in rats and against microsporosis in guinea pigs, has been selected for clinical evaluation.

Antimycotic activity of some amino acids against dermatophytes

20 amino acids were assayed at 1% concentration for their toxicity against the mycelial growth of two dermatophytes viz., Microsporum gypseum and Trichophyton mentagrophytes. L-Cysteine hydrochloride exhibited absolute toxicity against both the test pathogens while DL-aspartic acid was found active against Microsporum gypseum only. The minimum inhibitory concentrations of L-cysteine hydrochloride was found to be 0.5 and 0.4% against M. gypseum and T. mentagrophytes, respectively, at which it showed mycostatic nature. However, the amino acid exhibited mycocidal activity at 0.9 and 0.8% against M. gypseum T. mentagrophytes, respectively. The spectrum of L-cysteine hydrochloride was studied at 1 and 0.5% concentrations against 24 human and animal pathogenic fungi and it was found to possess broad range of activity. The mycotoxicity of amino acid remained unaltered at high temperature, on autoclaving and against high inoculum density. Besides, it showed stronger activity in comparison to four antimycotic drugs viz., griseofulvin, 5-bromosalicyl-4-chloranilidine, acidum undecylenicum and nystatin.

Lyophilized microculture susceptibility test for ketoconazole, miconazole, clotrimazole, and griseofulvin against dermatophytes

A lyophilized microculture antimycotic susceptibility testing system for ketoconazole, miconazole, griseofulvin, and clotrimazole is described. Microculture plates were loaded with 100 microliters of medium and 10 microliters of appropriate concentrations of the four antimycotics and were lyophilized to complete dryness. The lyophilized plates were stored at -70 degrees C or 4 degrees C or in a desiccator at 25 degrees C. Samples from each storage condition were rehydrated at 1, 2, 3, 4, 5, 6, 8, 10, and 12 months and inoculated with Trichophyton mentagrophytes (Robin) Blanchard ATCC 18748. All of the minimal inhibitory concentrations (MICs) generated from the lyophilized microcultures were within one experimental dilution of MICs derived from fresh microcultures. The ability of reconstituted lyophilized microcultures to consistently produce MICs comparable to MICs derived from fresh microcultures was characterized. Nine dermatophyte isolates were tested five times each over a 70-day period. The MICs derived were reproducible and comparable to MICs determined by freshly prepared microculture tests. Lyophilization of freshly prepared antimycotic-containing microcultures does not alter the MIC resolution of the testing system and provides an effective method of storage of prepared antimycotic tests for ketoconazole, miconazole, clotrimazole, and griseofulvin.

The microsporidian spore invasion tube. II. Role of calcium in the activation of invasion tube discharge

A swelling response by the polaroplast organelle initiated microsporidian invasion tube extrusions by Glugea hertwigi spores. The tumescence was induced by the displacement of internal calcium. Sodium citrate, phosphate, and the calcium ionophore A23187 were effective in initiating polaroplast swelling and spore discharge; however, the addition of external CaCl2 switched the expanded polaroplasts to a contracted state and blocked spore discharge. Unlike CaCl2, equivalent concentrations of KCl, NaCl, MgCl2, and BaCl2 did not induced polaroplast contraction, and spore discharge was not blocked. 45CaCl2 readily incorporated into spores with expanded polaroplasts; however, little calcium uptake was apparent in spores with contracted polaroplasts. Metallochromic arsenazo III yielded a color spectrum characteristic of the dye-Ca++ complex in the polaroplast region; furthermore, a membrane association with calcium was indicated by strong chlorotetracycline fluorescence within the polaroplast; this fluorescence was extinguished by pretreating spores with ionophore A23187. An association of the membrane with calcium was also indicated by a potassium ferrocyanide-osmium tetroxide technique. All evidence indicates that an internal calcium displacement is an important initial step in the swelling response of the polaroplast organelle.

Antifungal activity of dermatological shampoos

The effect of several "medicated" shampoos on the growth of a variety of fungi was determined. Shampoos with as low as 0.5% coal tar were inhibitory to all strains, 2.5% selenium sulfide and 1 and 2% zinc pyrithione were significantly more inhibitory. Since these shampoos have substantivity for the human scalp, they may be useful as adjunctive therapy to griseofulvin in the treatment of scalp infections and minimize the risk of spread of viable spores to others in the environment.

Effectiveness of a topical antifungal agent (clotrimazole) in dogs

An infection of Trichophyton mentagrophytes was induced in 13 dogs, and of Microsporum canis, in 9 dogs. After the lesions became established, they were assigned to a group for clotrimazole treatment, miconazole treatment, or no treatment. Treatments were applied one daily for 28 days, using a double blind method. The lesions were evaluated by daily scoring of severity and by semiweekly culturing throughout the treatment period. Compared with untreated controls, the response to clotrimazole was significantly better from day 11 until the end of the study. The response to clotrimazole equaled or occasionally exceeded that to miconazole.

Antifungal properties of some pyrazolyl-alkyl-sulfides. Electron microscopic evidence in two dermatophytes and Candida albicans

Four 5-amino-4-alkylthio-pyrazoles were synthesized and their antifungal activity was evaluated in vitro in Trichophyton mentagrophytes, Microsporum cookei and Candida albicans. The compounds slightly influenced the growth kinetics of the yeast, but at concentrations ranging from 20 to 40 micrograms/ml completely prevented the mycelial growth of the two dermatophytes cultivated on Sabouraud's agar medium. An electron microscopic study, undertaken by using the most active compound, showed that in C. albicans mitochondria were the only cell targets affected whereas in the dermatophytes cell wall, plasmalemma and the main cytoplasmic organelles were damaged in various degrees. Since the most remarkable alterations were connected with membrane abnormalities, the cytological changes observed were tentatively interpreted as a consequence of the compound intrusion into the lipid bilayer of the membranes, since the drug is lipophilic in nature.

Treatment of dermatomycoses with ketoconazole

Forty patients (22 males and 18 nonpregnant females) with tegumentary mycoses were treated with ketoconazole (R41,400). The group included 39 patients with dermatophytoses and one with tinea versicolor. Ketoconazole was administered in one dose per day taken with water 2 hr before or after breakfast for one month; patients weighing < 30 kg received 100 mg of ketoconazole per day, whereas those weighing > 30 kg received 200 mg per day. Twenty-one patients had complete clinical and mycologic cure, two responded clinically but the last culture was positive, eight had partial improvement, and three had no improvement at all. In six cases the treatment was stopped (in one because of gastric intolerance). The main adverse effect of ketoconazole was nausea; only one patient had vomiting. The results indicate that ketoconazole is a safe and effective drug for treatment of dermatomycosis.

Conditioned pathogenicity of Microsporum gypseum biochemical mutants

Experimental infections of guinea pigs with three biochemical mutants of Microsporum gypseum are described. Under normal conditions the mutants are avirulent. The virulence became manifested in two mutants (1) when substance necessary for growth of individual mutants were brought into the place of inoculation, (2) when the defense mechanism of the organism was altered with the application of immunosuppressive drugs. One of the mutants was permanently avirulent. The importance of experimental results for explanation of conditioned pathogenicity of some dermatophytes is discussed.

[Clathrates of unsaturated hydroxamic acids with antifungal acitivity]

Urea complexes of 10-undecen-hydroxamic acid (III) and trans-2-dodecen-hydroxamic acid (IV) were prepared with the aim of testing antifungal activity. No significant difference of activity between the complexes and corresponding hydroxamic acids was demonstrated.

Antimicrobial activity of quaternary ammonium salts of some saturated heterocycloalkyl amines [1]

Antimicrobial activity of N-alkyl-N-dodecylpiperidinium bromides and N-ethyl-N-dodecylheterocycloalkyl ammonium bromides (pyrrolidine, morpholine, perhydroazepine) determined on grampositive and gramnegative bacteria, yeasts and moulds, presented as minimum inhibition concentration (MIC). Comparison of the effect of change of structure: lengthening of alkyl chain, change of heterocyclic ring. Change in the length of alkyl chain markedly affects the antimicrobial activity, change of heterocyclic ring has no substantial effect. The most active compounds were N-heptyl-and N-hexyl-N-dodecylpiperidinium bromides.

Comparative study of the growth inhibition of vegetative hyphae of some dermatophytes and keratinophilic fungi on glucose-peptone-agar with griseofulvin

By the method of Jesenská and Danilla [29] the growth inhibition of vegetative hyphae of colonies of 12 species of dermatophytes and keratinophilic fungi on the surface of glucose-peptone-agar with incorporated griseofulvin has been established. It could be concluded that the sensitivity of hyphae to griseofulvin is neither connected with the taxonomic position and ecological classification of these microscopic fungi, nor with their ability to survive in the soil, or with their pathogenity etc. - In Trichophyton rubrum some hyphae were found which were extremely resistant to griseofulvin. - The extablished values allow to make an objective comparison of the sensitivity level of vegetative hyphae of dermatophytes and keratinophilic fungi to griseofulvin in further geographical regions, at different times and in different laboratories. - In the discussion further possibilities in this direction are developed.

1-[4-(4-Chlorophenyl)-2-(2,6-dichlorophenylthio)-n-butyl]-1H-imidazole nitrate, a new potent antifungal agent

The preparation and antifungal properties of 1-[4-(4-chlorophenyl)-2-(2,6-dichlorophenylthio)-n-butyl]-1H-imidazole nitrate 1 are described. It is particularly effective against in vivo Candida albicans infections (mice), maintaining good activity down to 0.25% formulation strength and showing unusually low reinfection rates after treatment is ended.

In vitro and in vivo photosensitized inactivation of dermatophyte fungi by heterotricyclic dyes

The ability of three heterotricyclic dyes to photosensitize dermatophyte fungi was studied with Trichophyton mentagrophytes and Microsporum gypseum. In vitro studies showed that methylene blue, neutral red, and proflavine were capable of killing these fungi when used in conjunction with broad-spectrum light. Proflavine, however, killed both fungi most rapidly and was used for further studies. Fungal killing by proflavine plus light was dependent on dye concentration, pH, light wavelength, and light intensity. Based on the in vitro studies, a treatment regimen was developed for in vivo use on experimentally infected animals. When treatment of guinea pigs inoculated with T. mentagrophytes was begun during fungal invasion, lesion formation at inoculated sites was either prevented or substantially reduced. When treatment was begun after lesion formation, however, light-plus-dyed treated sites showed only slightly faster curing than untreated sites.

Resistance of selected saprobic and zoopathogenic fungi to cycloheximide

Spore germination was used as an assay to measure the sensitivities of selected fungi (Achlya bisexualis, Cladosporium sp., Trichophyton mentagrophytes and Microsporum gypseum) to cyclohexamide and to determine their abilities to adapt to the drug. Two patterns of response were noted. The saprobes, A. bisexualis and Cladosporium sp., demonstrated acquired resistance. Spores from hyphae previously exposed to cycloheximide either germinated in the presence of concentrations of the drug that completely inhibited spores from unexposed hyphae (Achlya), or germinates with a shorter lag and to a greater extent in the presence of the antibiotic than did spores from unexposed hyphae (Cladosporium). Hyphae of Achlya adapted at concentrations of cycloheximide in which spores did not germinate and hyphae of Cladosporium adapted more rapidly than spores. Achlya adapted to only 12 muM-cycloheximide whereas Cladosporium acquired resistance to 18 mM-cycloheximide. These fungi lost this acquired resistance after a single transfer to media lacking cycloheximide. The zoopathogens, T. mentagrophytes and M. gypseum, had a contrasting response, indicating constitutive resistance. Conidia from unexposed hyphae showed 90 to 100% germination on media containing up to 18 mM-cycloheximide; prior exposure to the drug did not affect their response.

[Investigations on the antimicrobial activity of amin-aldehyde-condensates. 2. Communication: unsymmetrically substituted animals of formaldehyde (author's transl)]

In the scope of our research about the antimicrobial activity of aldehyde-amin-condensates a number of partly new unsymmetrically substituted animals was synthesized by reaction of formaldehyde with different secondary amines. Structures and physically constants are shown in the tables 1 and 2. The antimicrobial activity is demonstrated by the results of the disktest (table 3), of the minimal inhibition concentration (MIC, table 4) and the suspension and area disinfecting tests following the method of the DGHM (tables 5 and 6). For this testing a standardized formulation was used to eliminate the different solubility effects of the various animals. This formulation does not influence the test results. It may be shown, that unsymmetrically substituted animals have both germistatic activity mainly versus Staphylococcus aureus and Bacillus subtilis and germicidal activity especially versus Pseudomonas aeruginosa, Proteus vulgaris, Trichophyton mentagrophytes and Micosporum gypseum.

Drug-induced changes in the plasma membrane of Microsporum canis. A preliminary freeze--fracture study

Commercial solutions of clotrimazole, tolnaftate and tolcyclate were tested for 12 h in cultures of Microsporum canis. They induced modifications in particle distribution, a blebbing of particle-free areas and the appearance of lamellar figures on the plasma membrane of fungus cells. The first two changes in the plasma membrane might be ascribed to a modification of the spectrin-like meshwork, while the third could be the result of a crystalline organization of membrane lipids.

Evaluation of the in vitro antifungal activity of allicin

Allicin was effective in vitro against Candida, Cryptococcus, Trichophyton, Epidermophyton, and Microsporum. The minimal inhibitory concentrations (MICs) of allicin against these organisms were 3.13 to 6.25 mug/ml by the agar dilution method and 1.57 to 6.25 mug/ml by the broth dilution method, using Sabouraud glucose (SG) medium. However decreased activity was demonstrated against Aspergillus. The MIC of allicin against various pathogenic fungi was affected considerably by differences in the experimental conditions, e.g., incubation time, inoculum size, type of medium, and medium pH. The MIC of allicin against Candida, Cryptococcus, and Aspergillus remained constant after more than 3 days of incubation, and that against Dermatophytes remained constant after more than 10 days of incubation. Decreasing the inoculum size increased the susceptibility to allicin. The antifungal activity of allicin was stronger on SG agar medium with a pH of 5.6 than on the same medium with a pH of 6.0 or higher. By microscopical observation, allicin induced morphological abnormalities in hyphae of Trichophyton mentagrophytes Morita. Percent germination of spores of the Morita strain at 24 h in SG agar medium was greatly decreased with an allicin concentration of 3.13 mug/ml, and the lethal dose for the spores was about four times higher than the fungistatic concentration. These results suggest that allicin inhibits both germination of spores and growth of hyphae.

[Antimycotic antibiotics (author's transl)]

A number of antibiotics having an antimycotic action are reviewed. The physicochemical and pharmacotoxicological properties, antifungal range, mechanisms of action, dosage and preparations of griseofulvin, amphotericin-B, natamycin, nystatin and pecilocin are discussed.

[Synthetic antimycotica (author's transl)]

In addition to the antimycotic antibiotics described in a previous paper (Tijdschr. Diergeneesk., 101, 900-904, (1976)), the drugs used in the treatment of dermatomycosis include a fairly large number of synthtic compounds showing a wide variety of chemical structures. These are partly old and occasionally even obsolete agents (often in use as early as prior to 1945); a number of these drugs are of more recent date. They will be discussed in the present paper. So far as is known, the physicochemical and pharmacotoxicological properties, antifungal range, mechanisms of action and preparations will be reviewed.

Studies on the biological effects of deuteriated organic compounds. III. Antifungal activity of perdeuteriated fatty acids on dermatophytes in vivo experimental microsporie in guinea pigs

Investigations on the antimycotic properties of perdeuteriated fatty acids were carried out on Microsporum cains infections in vivo. The study was performed on experimental microsporie in guinea pigs using four different methods, all based on the ability of M. canis to cause alopecia. Perdeuteriated n-hendecanoic acid showed in vivo a statistically significant enhanced antimycotic effect compared to its unlabelled analogue. This is in accordance with our previous observations in vitro conditions. The remaining perdeuteriated fatty acids (C12--C18) showed no statistically significant growth retarding effect on M. canis infections in guinea pigs when compared with their unlabelled analogues. The present study attempts to ascertain if some perdeuteriated fatty acids have any antifungal activity in vivo conditions. Our previous papers (3,4) concerning the evaluation of the antifungal activity of some perdeuteriated fatty acids on dermatophytes in vitro, demonstrated that the perdeuteriation of n-hendecanoic acid, lead to a pronounced antimycotic effect on common dermatophytes as e.g. E. floccosum, T. rubrum, M. canis and T. mentagrophytes. As our previous results indicate a decreasing of fungistasis with an increasing carbon-chain length of the perdeuteriated fatty acids, we have attempted to verify this observation in vivo conditions. A special interest was, of course, focused on the most promising compound, the perdeuteriated n-hendecanoic acid.

Studies on the biological effects of deuteriated organic compounds. I. Antifungal activity of perdeuteriated fatty acids on dermatophytes in vitro

The antifugal activity of some perdeuteriated fatty acids, with normal chain 11 to 18 carbon atoms, was investigated on common dermatophytes Epidermophyton floccosum, Microsporum canis, Trichophyton mentagrophytes and T. rubrum under in vitro conditions. These studies were performed by dilution technique and with respiratory measurements, Perdeuteriation of some fatty acids increases their inhibitory effect on the dermatophyte growth. Perdeuteriated n-hendecanoic acid proved to be the most active of the substances tested. Possible mechanisms behind the enhanced antifungal activity due to the perdeuteriation of fatty acids are discussed.

Isolation of Ethyl p-methoxycinnamate, the major antifungal principle of Curcumba zedoaria

An antifungal principle of the dried rhizomes of Curcuma zedoaria was extracted with hot ethanol. By successive chromatography on neutral alumina and silica gel, three antibiotic compounds A, B, and C, all active against Trichophyton rubrum, Aspergillus niger and Saccharomyces cerevisiae, were obtained in chemically pure form. By uv, ir, pmr and ms analysis, the structure of the most abundant one of these compounds (C, 69.8%; H, 6,8%; and 0.23.4%) was assigned as ethyl p-methoxycinnamate (EPMC). The proposed structure was confirmed by synthesis and comparison of the chemical and biological properties of the natural and synthetic products. EPMC inhibits the growth of Trichophyton rubrum, Aspergillus niger, Saccharomyces cerevisiae and Epidermophyton floccosum at a concentration less than 10 mug/ml; A. fumigatus, Penicillium purpurogenum, Trignoposis variabilis, Microsporum gypseum, Sclerotium rolifsii, Geotricular candiade, Fusarium oxysporum and Helminthosporium oryzale at a concentration less than 25 mug/ml; and Candida krusei and T. mentagrophytes At a concentration less than 50 mug/ml. The spores of T. rubrum Lose viability or ability to germinate when wxposed to its ethanolic solution (30 mug/ml) for 2 hours.

On the fungitoxicity of some new thiocyanatopyrazole derivatives: electron microscopical study in Trichophyton mentagrophytes

Four thiocyanatopyrazole derivatives were synthesized and their fungistatic activity was demonstrated in vitro against a number of dermatophytic fungi. In Trichophyton mentagrophytes, the most active compound induced as unusual increase of the plasma membrane with production of intra and extracytoplasmic complexes, a deterioration of nuclear and mitochondrial membranes and a formation of autophagic-like vacuoles. Plasmolysis, accompanied by an almost complete disorganization of cytoplasmic structures, seemed to be the final event. A possible mechanism of action of the compounds were discussed.