Microsporum Cookei Research Articles

Ultraviolet-mediated antimycotic activity of α-terthienyl onMicrosporum cookei

Alpha-terthienyl (alpha-T) in the presence of UV-A irradiation reduced the growth rate of Microsporum cookei. In the dark, alpha-T accumulated in small diffuse vacuoles within the hyphae. After UV-A treatment, alpha-T caused damage to the membranes of the nucleus, mitochondria and endoplasmic reticulum. Plasmolytic and autolytic changes occurred resulting in plasma membrane breakage and cell wall aberrations. UV-A activated alpha-T would appear to target membrane proteins.

Electron microscopy of Microsporum cookei after 'in vitro' treatment with protoanemonin: a combined SEM and TEM study.

The ranunculaceous derivative protoanemonin (PrA) was studied as an antifungal agent on the dermatophyte Microsporum cookei. The ultrastructural changes that PrA brought about in this fungus were observed with both the transmission and scanning electron microscopes. The main anomalies noted were abnormally shaped hyphae and within the cytoplasm, multimembranous bodies which were irregular in shape and size, and tubules of 25 and 60 nm in diameters. Mitochondria, nuclei and vacuoles were also variously affected by PrA. Although multifarious, the observed cellular alterations in M. cookei can be considered the result of a PrA interaction with cytoplasmic microtubules. Since these cell structures contain a great number of ASH groups, our previous hypothesis, that sulphydryl groups are the primary targets of this molecule, appears to be supported.

Antifungal activity of sesquiterpene lactones

Forty-five sesquiterpene lactones were screened for their antifungal activities against Microsporum cookei, Trichophyton mentagrophytes and Fusarium sp. The screening tests showed that a majority of sesquiterpene examined possess at least weak antifungal activity, the eudesmanolides being the most active. The antifungal activity of sesquiterpene lactones cannot be explained by the presence or absence of two potential active sites (the exocyclic methylene and, in pseudoguaianolides, a β-unsubstituted cyclopentenonel) but other functions must play a role in enhancing or reducing this activity.

Antifungal activity of helenin and isohelenin

Two sesquiterpene lactones, helenin and isohelenin, were examined for their activity against 16 species of fungi. These compounds varied greatly in their antifungal activities. At concentrations of 10 μg/ml, the lactones strongly inhibited the growth of Microsporum cookei, Trichophyton mentagrophytes and Trichothecium roseum, while other fungi were only inhibited by considerably higher levels (100–1000 μg/ml). It is suggested that these secondary plant metabolites might be of potential use as antifungal agents, especially if their activity and specificity could further be enhanced through modifications in their chemical structure.

Degradation of wool by saprotrohic fungi

Strains of Acremonium roseum and Chaetomium globosum were tested for their ability to attack the protein components of wool by culturing the fungi in basal medium containing wool and monitoring changes in pH and soluble protein levels occurring in the medium. Net increases in soluble protein and pH were detected in the cultures of A. roseum, C. globosum, and the positive control, Trichophyton mentagrophytes. To test for keratin denaturation by sulfite production (sulfitolysis), human hairs were exposed to the fungi in culture. Overgrown hairs were stained by the tetrazonium method, a test specific for compounds produced by sulfitolysis. Isolates of Trichophyton tonsurans, T. rubrum, T. terrestre, Microsporum cookei, and nondermatophytic saprotrophic fungi were also tested for sulfitolysis. Positive results for sulfitolysis were obtained with T. mentagrophytes, T. tonsurans, T. rubrum, T. terrestre, and M. cookei; A. roseum, C. globosum, and the remaining species were negative.

Microsporum cookei as the suspected cause of ringworm in a dog.

Microsporum cookei as the suspected cause of ringworm in a dog.

Studies on the phospholipase A of dermatophytes

The presence of phospholipase A activity was detected in three dermatophytes:Microsporum cookei, Trichophyton mentagrophytes, andEpidermophyton floccosum. The activity was always higher inT. mentagrophytes than inM. cookei andE. floccosum. All exhibited phospholipase A1 and A2 activities, but the activity was largely A2 inM. cookei and A1 inE. floccosum. T. mentagrophytes possessed almost equal activities of phospholipase A1 and A2.

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.

Phospholipid and fatty acid composition of Microsporum cookei: effect of exogenous unsaturated fatty acids.

Total phosphatide content of Microsporum cookei increased by about two fold when palmitoleate was supplemented into the growth media. However, the phosphatide content decreased on supplementation of oleate or linoleate. The ratio of unsaturated to saturated fatty acids decreased significantly (three fold) on palmitoleate supplementation.

The prevalence of geophilic dermatophytes in soils of the Illawarra area of New South Wales.

One hundred and forty-nine soil samples were collected from 27 suburbs within the Illawarra areas of New South Wales. Microsporum gypseum was isolated from 74.5%, Microsporum cookei from 56.4% and Keratinomyces ajelloi from 55.7% of soil samples. Two or more of these dermatophytes were simultaneously isolated from one soil sample on 93 occasions (62.4%). Trichophyton terrestre was not isolated, however Trichophyton mentagrophytes was isolated on two occasions, although repeat cultures of soil from the vicinity proved negative. No dermatophyte was isolated from only two of the 149 samples (1.3%) and Chrysosporium species were isolated from 22.2% of soils tested. The potential pathogenicity of such a high content of certain geophilic dermatophytes within soils of this area is discussed.

Investigation of keratinophilic fungi from soils in western Australia a preliminary survey.

In order to determine which species of geophilic dermatophytes were present in Western Australian soils 299 samples were investigated. These samples were collected from a range of locations, 208 towns throughout the state and 91 samples from the Perth Metropolitan area. Most samples were collected from areas frequented by people and animals, such as home gardens, parks and animal yards. Of the total 299 soils, 271 (90.6%) yielded keratinophilic fungi. A total of 181 dermatophytes were isolated, and there were 205 isolations of other keratinophilic fungi. Microsporum gypseum (30.7%) was the most prevalent dermatophyte recovered from soil followed by Microsporum cookei (21.7%) and then Trichophyton ajelloi (8.0%). No other dermatophytes were recovered. Chrysosporium indicum was the most common of all the keratinophilic fungi and was isolated from 50.1% of the samples. Mixed growth was obtained from 33.5% of the soil samples.

An unusual lipid in the human pathogenic fungus Epidermophyton floccosum

The dermatophyte Epidermophyton floccosum contains an unusual lipid characterized as 1(3),2-diacylglyceryl-3(1)- O-4′-( N, N, N-trimethyl)homoserine. Its concentration in E. floccosum is approx. 15% of the polar lipids. The role of this lipid in the biosynthesis of polar lipids and fatty acids is not yet known. However, it is interesting from a chemotaxonomic viewpoint that the lipids from two other genera of dermatophyte, Microsporum cookei and Trichophyton rubrum do not contain this novel lipid.

Biochemical studies of pigments from a pathogenic fungus;Microsporum cookei VI. Formation of a xanthomegnin-bypass to the mitochondrial electron transport system

Enzymatic redox response of xanthomegnin was studied by means of rat liver mitochondria and the possibility of a xanthomegnin-bypass to mitochondrial electron transport system is suggested.

Recherche sur les kératinophiles du sol et leur incidence sur la pathologie cutanée humaine dans la région lyonnaise

Between 1967 and 1977, the systematic research of keratinophiles of the ground in a radius of 30--50 km around Lyon, has shown the ubiquitarian predominance of Microsporum nanum, which is probably the most ancient occupant of the ground. The most intensive areas of human and animal occupation in the Rhodanian tract show the predominance of Microsporum gypseum, which is scarcely found in man. Sporadic localizations, tightly limites, bound to cirulcation axes and international gathering, let us detect Microsporum cookei, Trichophyton verrucosum, Trichophyton mentagrophytes, Chrysosporium keratinophilum, and Keratinomyces ajelloi. However, in the last years, a progressive extension of recently imported kinds and a decrease in native kinds appears to have occurred.

Biochemical studies of pigments from a pathogenic fungus Microsporum cookei IV. Enzymatic reduction of xanthomegnin by mitochondria and microsomes.

The enzymatic oxido-reduction of xanthomegnin has been investigated spectroscopically using rat liver mitochondria and microsomes. Xanthomegnin, a binaphthoquinone pigment isolated from a dermatophyte Microsporum cookei, has been shown to strongly uncouple mitochondrial respiration and has been suggested to exert a cyto-toxic effect in animals. The redox response of this pigment has also been suggested to participate in uncoupling of oxidative phosphorylation in mitochondria, by forming a bypass to the electron transport system. In the presence of succinate or L-glutamate as substrate, xanthomegnin was reduced by mitochondria after dissolved oxygen was completely consumed. This suggests that complex IV of the respiratory chain of mitochondria is concerned with enzymatic reduction of xanthomegnin and that its redox response is not involved in the uncoupling effect on mitochondrial respiration. On the other hand, when NADH was added, xanthomegnin was immediately reduced by mitochondria, submitochondrial particles, and microsomes, indicating the xanthomegnin is reduced by NAD-linked electron transport system of mitochondria and microsomes. Xanthomegnin reduced by ascorbate was auto-oxidized by dissolved oxygen.These results would indicate that xanthomegnin forms an electron transport bypass to the NAD-linked respiratory chain and readily oxidize cytosol NADH. This may cause the cyto-toxic effect to animals.

病原性真菌?EＥｐｉｄｅｒｍｏｐｈｙｔｏｎ ｆｌｏｃｃｏｓｕｍ?Fの脂質構成とその発育による変動

Qualitative and quantitative changes of lipid components during the growth stages were studied in E. floccosum. The acyl group components of total lipids of Trichophyton rubrum and Microsporum cookei were also examined. The lipids of E. floccosum amounted to approximately 4% of the dry cell weight. Neutral lipids mainly consisted of triglycerides and sterols, and major polar lipids were phosphatidylcholine, phosphatidylethanolamine, and an unknown lipid X. The fatty acids in tryglycerides and phospholipids were palmitic, palmitoleic, stearic, oleic, and linoleic acids. The unknown polar lipid X which appeared between phosphatidylethanolamine and cardiolipin on thin layer chromatography plates contained no phosphorus. There was no significant change in the fatty acid components of E. floccosum and T. rubrum during the cell growth, whereas profound changes occurred in M. cookei. The sterol components of E. floccosum showed striking changes depending on the growth stage.

病原性真菌Microsporum cookei産生色素xanthomegninの酸化還元反応と細胞毒作用

病原性真菌Microsporum cookei産生色素xanthomegninの酸化還元反応と細胞毒作用

Distribution of nuclei in macroconidia of dermatophytes.

The distribution of nuclei in macroconidia was appraised in the following five dermatophyte species:Epidermophyton floccosum, Microsporum cookei, Microsporum gypseum, Trichophyton ajelloi andTrichophyton vanbreuseghemii. In all strains under investigation the number of cells in a macroconidium displays no correlation with the average number of nuclei in a cell of a given macroconidium; cells situated in the central part of the macroconidium tend to have a higher number of nuclei than cells at the periphery. The explored strains mutually differ significantly in the prevalence of nuclei in the left (basal) and right (apical) part of the macroconidium.

Biochemical studies of pigments from the pathogenic fungus, Microsporum cookei.

Biochemical studies of pigments from the pathogenic fungus, Microsporum cookei.

Isolation ofMicrosporum cookeifrom a human case

A case of ringworm due to Microsporum cookei in a 20-months-old child is described. This is the first recorded isolation of this dermatophyte from a human host in Australia.