Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “MICROSPORUM”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 235 records · Page 13Linked to original sources
PubMed2006

A kerion celsi caused by Microsporum gypseum: unusual direct mycological examination.

A case of kerion celsi caused by Microsporum gypseum is documented. The patient was a 6-year-old girl with a 2-cm purulent lesion on the scalp. Direct mycological examination of the hair showed hyphae with extremely numerous spindle-shaped macrospores. The species identification was confirmed by 28S ribosomal DNA sequencing. The presence of numerous macrospores is unusual in direct mycological examination, but could be an indication for M. gypseum.

Child↗
PubMed2006

Dystrophic onychomycosis due to Microsporum gypseum.

A case of onychomycosis with nail dystrophy due to Microsporum gypseum in a healthy 35-year-old woman is described. The infection had a 2-year history, occurring in the site of a nail trauma sustained in a fall from a horse. Diagnosis was based on mycological examination (direct microscope observation and culture). Clinical and mycological recovery was achieved after local treatment with ciclopiroxolamine nail solution and pulsed systemic terbinafine therapy.

Adult↗
PubMedDate not supplied

Lack of efficacy of 6-week treatment with oral terbinafine for tinea capitis due to Microsporum canis in children.

Twenty-two children aged 2 to 9 years with noninflammatory tinea capitis due to Microsporum canis were evaluated in an open clinical pilot study run from January 1994 to July 1995. Each child was given oral terbinafine according to body weight for 6 weeks. Mycologic evaluation was done at the end of treatment and after follow-up periods of 4 and 8 weeks. None of the patients achieved complete mycologic cure by the end of the treatment period. Four weeks later complete mycologic cure was established in nine patients, and on final evaluation in seven. The treatment was very well tolerated by all the children. No systemic adverse effects were noted. According to our data, a 6-week course of oral terbinafine is inadequate for tinea capitis due to M. canis in children. Further study is needed to determine the most appropriate duration of therapy.

Administration, Oral↗
PubMedDate not supplied

Tinea faciei in an infant caused by Microsporum gypseum simulating a dry impetigo.

We report a 14-month-old White boy who was referred to our dermatology unit for evaluation of a skin eruption on his nose. The initial examination led us to the clinical diagnosis of impetigo. The mycologic studies found an uncommon dermatophyte agent, Microsporum gypseum. The main differential diagnosis of tinea faciei is discussed.

Administration, Topical↗
PubMedDate not supplied

Fontana-positive grains in mycetoma caused by Microsporum canis.

We describe mycetoma caused by Microsporum canis occurring in a 9-year-old African-American girl. Pathologic evaluation showed a granulomatous dermatitis with numerous large fungal grains containing septate hyphae that were Fontana-Masson positive. Two cultures of pure grains grew M. canis. Mycetoma due to dermatophytes is very uncommon. The few instances reported have been pseudomycetoma (grains in the absence of sinus tracts). Our patient developed sinus tracts (true mycetoma). No prior reports were found of M. canis staining Fontana positive. Differentiation of dermatophyte-induced mycetoma from kerion is important because mycetomas require a combined approach including surgical debridement in addition to oral antifungal therapy.

Child↗
PubMed2001

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.

Administration, Oral↗
PubMed2001

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.

Amino Acid Sequence↗
PubMed2004

The novel azole R126638 is a selective inhibitor of ergosterol synthesis in Candida albicans, Trichophyton spp., and Microsporum canis.

R126638 is a novel triazole with in vitro activity similar to that of itraconazole against dermatophytes, Candida spp., and Malassezia spp. In animal models of dermatophyte infections, R126638 showed superior antifungal activity. R126638 inhibits ergosterol synthesis in Candida albicans, Trichophyton mentagrophytes, Trichophyton rubrum, and Microsporum canis at nanomolar concentrations, with 50% inhibitory concentrations (IC(50)s) similar to those of itraconazole. The decreased synthesis of ergosterol and the concomitant accumulation of 14 alpha-methylsterols provide indirect evidence that R126638 inhibits the activity of CYP51 that catalyzes the oxidative removal of the 14 alpha-methyl group of lanosterol or eburicol. The IC(50)s for cholesterol synthesis from acetate in human hepatoma cells were 1.4 microM for itraconazole and 3.1 microM for R126638. Compared to itraconazole (IC(50) = 3.5 microM), R126638 is a poor inhibitor of the 1 alpha-hydroxylation of 25-hydroxyvitamin D(3) (IC(50) > 10 microM). Micromolar concentrations of R126638 and itraconazole inhibited the 24-hydroxylation of 25-hydroxyvitamin D(3) and the conversion of 1,25-dihydroxyvitamin D(3) into polar metabolites. At concentrations up to 10 microM, R126638 had almost no effect on cholesterol side chain cleavage (CYP11A1), 11 beta-hydroxylase (CYP11B1), 17-hydroxylase and 17,20-lyase (CYP17), aromatase (CYP19), or 4-hydroxylation of all-trans retinoic acid (CYP26). At 10 microM, R126638 did not show clear inhibition of CYP1A2, CYP2A6, CYP2D6, CYP2C8, CYP2C9, CYP2C10, CYP2C19, or CYP2E1. Compared to itraconazole, R126638 had a lower interaction potential with testosterone 6 beta hydroxylation and cyclosporine hydroxylation, both of which are catalyzed by CYP3A4, whereas both antifungals inhibited the CYP3A4-catalyzed hydroxylation of midazolam similarly. The results suggest that R126638 has promising properties and merits further in vivo investigations for the treatment of dermatophyte and yeast infections.

25-Hydroxyvitamin D3 1-alpha-Hydroxylase↗
PubMed1979

N-demethylation of nicotine and reduction of nicotine-1'-N-oxide by Microsporum gypseum.

Several microorganisms were examined for their abilities to convert S-nicotine into nornicotine. Five microorganisms including Microsporum gypseum (ATCC 11395) produced nornicotine and three unknown metabolites. M. gypseum efficiently reduced nicotine-1'-N-oxide to nicotine, but no nornicotine was obtained when the N-oxide was used as substrate.

Chemical Phenomena↗
PubMed1972

Physiological and biochemical changes associated with macroconidial germination in Microsporum gypseum.

A study was made of the metabolic processes associated with macroconidial germination in Microsporum gypseum. The optimum conditions for stimulation of endogenous respiration, changes in chemical composition as germination proceeds, and the uptake and synthetic fates of amino acids, glucose, and uracil were investigated. The assimilation and conversion of (14)C-glucose, (14)C-amino acids, and (14)C-uracil into the cell pool and into trichloroacetic acid-precipitable material were studied during the early stages of germination (i.e., prior to germ-tube emergence). The macroconidia were not metabolically inert for any significant period of time after exposure to germination conditions. Rather, the spores rapidly assimilated all metabolites and slowly converted them into macromolecules. Investigations of the effect of inhibitors of nucleic acid and protein synthesis prior to germ-tube emergence and during early germ-tube elongation suggested significant changes in metabolism and cell permeability may be correlated with the emergence of germ tubes. Radioactivity of incorporated glucose was found to be associated largely with the lipid fractions of the macroconidia early in germination.

Amino Acids↗
PubMed1982

Ultrastructure of the invasion of human hair in vitro by the keratinophilic fungus Microsporum gypseum.

The pattern of invasion of human hair in vitro by the dermatophyte Microsporum gypseum was studied by transmission and scanning electron microscopy. Mycelia that invaded the hair cortex through the edge of cuticles showed a flattened "frond" growth in contrast to the filamentous form seen on ordinary laboratory media. The frond cells were characterized by the presence of vesicles formed by invaginations of plasmalemma, and lomasomes were prominent in the region adjacent to the hard keratinized tissue of the hair cortex being degraded as well. The initial perforating organ, which originated from the frond mycelium, appeared as an enlarged spherical cell which integrated with the laterally branched hyphae, as revealed by analysis of a three-dimensional model reconstructed from a series of sections. The fully developed perforating organ consisted of a column of wide and short cells which penetrated perpendicularly through the hair cortex. Through the medulla the filamentous hyphae had grown profusely in a longitudinal direction. Our studies confirm earlier light microscope observations and provide new ultrastructural details on the development of the eroding frond and the perforating organ.

Cell Membrane↗
PubMed2002

Secreted metalloprotease gene family of Microsporum canis.

Keratinolytic proteases secreted by dermatophytes are likely to be virulence-related factors. Microsporum canis, the main agent of dermatophytosis in dogs and cats, causes a zoonosis that is frequently reported. Using Aspergillus fumigatus metalloprotease genomic sequence (MEP) as a probe, three genes (MEP1, MEP2, and MEP3) were isolated from an M. canis genomic library. They presented a quite-high percentage of identity with both A. fumigatus MEP and Aspergillus oryzae neutral protease I genes. At the amino acid level, they all contained an HEXXH consensus sequence, confirming that these M. canis genes (MEP genes) encode a zinc-containing metalloprotease gene family. Furthermore, MEP3 was found to be the gene encoding a previously isolated M. canis 43.5-kDa keratinolytic metalloprotease, and was successfully expressed as an active recombinant enzyme in Pichia pastoris. Reverse transcriptase nested PCR performed on total RNA extracted from the hair of M. canis-infected guinea pigs showed that at least MEP2 and MEP3 are produced during the infection process. This is the first report describing the isolation of a gene family encoding potential virulence-related factors in dermatophytes.

Amino Acid Sequence↗
PubMed1970

Biochemical changes during fungal sporulation and spore germination. I. Phenyl methyl sulfonyl fluoride inhibition of macroconidial germination in Microsporum gypseum.

Macroconidia of Microsporum gypseum release free amino acids into the medium during germination. A single alkaline protease is also found in the germination supernatant fraction. The purified protease is capable of hydrolyzing isolated spore coats in vitro. Phenyl methyl sulfonyl fluoride (PMSF) is an effective inhibitor of the protease. Incorporation of PMSF at 10(-4)m into the germination system inhibits spore germination and the release of free amino nitrogen. Addition of PMSF after germ tube emergence is completed has no effect on subsequent outgrowth. The addition of exogenous purified protease to quiescent spores results in more than a 2.5-fold increase in germinated spores. It is concluded that spore coat proteolysis is an essential event in the germination of dermatophyte macroconidia. A model system to explain macroconidial germination response to inhibition, temperature shift, and addition of protease is presented.

Alkaline Phosphatase↗
PubMed1970

Relationship of nuclear segregation and macroconidial germination in Microsporum gypseum.

Microsporum gypseum macroconidia germinated at 37 C possessed from one to eight nuclei per germinated spore compartment. The distribution of nuclei per spore compartment was the result of a random packaging of nuclei from the available nuclear population. Partial inhibition of germination by incubation at 25 C or at 37 C in the presence of 10(-4)m phenyl methyl sulfonyl-fluoride resulted in an enrichment of germinated spores containing high numbers of nuclei per compartment. The selection for higher nuclear numbers was statistically significant. Compartments possessing high numbers of nuclei appeared to be precommitted to spore germination since they were not sensitive to germination inhibition. The effect of incubation temperature variation on spore germination is discussed with respect to the organism's natural environment.

Cell Nucleus↗
PubMed1970

Macroconidial germination in Microsporum gypseum.

Biochemical events which occur during macroconidial germination have been studied in the dermatophyte Microsporum gypseum. The specific activity levels of various metabolic enzymes have been assayed during germination time periods. The accumulated levels of several of these enzymes, as a function of exogenous carbohydrate source, have been investigated. M. gypseum was found to possess a constitutive glyoxalate shunt, a constitutive glucokinase, a fructose phosphoenolpyruvate transferase, and a mannitol phosphoenolpyruvate transferase. The integration of endogenous reserve utilization during germination is discussed. The purification and properties of an alkaline phosphatase and its possible relationship to sporulation and spore germination also are described.

Alkaline Phosphatase↗
PubMed1970

Isolation and preliminary characterization of developmental mutants from Microsporum gypseum.

Developmental mutants affected in either sporulation or spore germination have been isolated from Microsporum gypseum with the aid of nitrosoguanidine or as spontaneously occurring mutants. The time course levels of several proteins temporally associated with conidial development have been assayed in the wild-type and mutant strains. The spore germination characteristics of two of the mutants are described. The relationship of alkaline protease accumulation to tyrosinase accumulation and spore germination is discussed.

Acyltransferases↗
PubMed1971

Respiratory chain of a pathogenic fungus, Microsporum gypseum: effect of the antifungal agent pyrrolnitrin.

Pyrrolnitrin has been reported to inhibit Bacillus megaterium primarily by forming complexes with phospholipids and to block electron transfer of Saccharomyces cerevisiae between succinate or reduced nicotinamide adenine dinucleotide (NADH) and coenzyme Q. We found that pyrrolnitrin inhibited respiration of conidia of Microsporum gypseum. In mitochondrial preparations, pyrrolnitrin strongly inhibited respiration and the rotenone-sensitive NADH-cytochrome c reductase. The rotenone-insensitive NADH-cytochrome c reductase, the succinate-cytochrome c reductase, and the reduction of dichlorophenolindophenol by either NADH or succinate were inhibited to a lesser extent. However, the activity of cytochrome oxidase was not affected by pyrrolnitrin. The extent of reduction of flavoproteins by NADH and succinate, measured at 465 - 510 nm, was unaltered; however, the reduction of cytochrome b, measured at 560 - 575 nm, was partially inhibited by pyrrolnitrin. The level of totally reduced cytochrome b was restored with antimycin A. We, therefore, concluded that the primary site of action of this antifungal antibiotic is to block electron transfer between the flavoprotein of the NADH-dehydrogenase and cytochrome b segment of the respiratory chain of M. gypseum.

Aniline Compounds↗