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At least 199 records · Page 11Linked to original sources
PubMed2001

Production of extracellular enzymes by Microsporum canis and their role in its virulence.

Microsporum canis is the most prevalent dermatophyte of domestic animals. Several enzymes produced by dermatophytes, particularly keratinases, are considered to play a role in the virulence of this fungus. To investigate the possible relationship between the clinical status of M. canis infection and enzymatic activity of isolates, we studied the relationship between keratinase, elastase, lipase and DNase levels produced in vitro by different isolates and virulence as expressed in a guinea pig model. Samples isolated from symptomatic dogs and cats showed a statistically significantly (P < 0.05) higher keratinase activity than samples isolated from asymptomatic animals. Experimental infection of guinea pigs showed that a strain with high in vitro keratinase activity induced acute infection, which resolved clinically and mycologically faster than the infection induced by a strain with low keratinase activity. This suggested a strong correlation between high keratinase activity and the development of symptoms. The same correlation was not observed for other enzymes tested.

Animals↗
PubMed1980

Mycetoma caused by microsporum audouinii. First reported case.

A 25-year-old black man had generalized tinea corporis for 19 years and had associated subcutaneous mycotic granuloma of the scalp and nape of the neck for 17 years. The dermatophyte from the skin was identified as Microsporum audouinii and responded to oral griseofulvin treatment. Biopsy specimens of the subcutaneous nodules revealed yellowish granules containing masses of irregularly septated hyaline hyphae with frequent vesicles. This fungus differed only in gross colonial morphology from the M. audouinii isolated from the skin and has also been identified as M. audouinii. The subcutaneous nodules were treated and controlled by amphotericin B and are still under treatment.

Adult↗
PubMed1982

Five-year follow-up of a man with subcutaneous mycetomas caused by Microsporum audouinii.

A black man with subcutaneous mycetomas caused by Microsporum audouinii was treated by a combination of griseofulvin, 18.5 g of amphotericin B, excisional surgery, and later, ketoconazole, resulting in a satisfactory arrest or cure of the clinical illness. Complications of therapy included residual impaired renal function and a change in hair color from black to a rust brown color. The continued use of the term mycetoma to describe such lesions is justified.

Adult↗
PubMed2004

Multiplication of an ancestral gene encoding secreted fungalysin preceded species differentiation in the dermatophytes Trichophyton and Microsporum.

Dermatophytes are human and animal pathogenic fungi which cause cutaneous infections and grow exclusively in the stratum corneum, nails and hair. In a culture medium containing soy proteins as sole nitrogen source a substantial proteolytic activity was secreted by Trichophyton rubrum, Trichophyton mentagrophytes and Microsporum canis. This proteolytic activity was 55-75 % inhibited by o-phenanthroline, attesting that metalloproteases were secreted by all three species. Using a consensus probe constructed on previously characterized genes encoding metalloproteases (MEP) of the M36 fungalysin family in Aspergillus fumigatus, Aspergillus oryzae and M. canis, a five-member MEP family was isolated from genomic libraries of T. rubrum, T. mentagrophytes and M. canis. A phylogenetic analysis of genomic and protein sequences revealed a robust tree consisting of five main clades, each of them including a MEP sequence type from each dermatophyte species. Each MEP type was remarkably conserved across species (72-97 % amino acid sequence identity). The tree topology clearly indicated that the multiplication of MEP genes in dermatophytes occurred prior to species divergence. In culture medium containing soy proteins as a sole nitrogen source secreted Meps accounted for 19-36 % of total secreted protein extracts; characterization of protein bands by proteolysis and mass spectrometry revealed that the three dermatophyte species secreted two Meps (Mep3 and Mep4) encoded by orthologous genes.

Aspergillus↗
PubMedDate not supplied

Itraconazole in the treatment of tinea capitis caused by Microsporum canis: experience in a large cohort.

Mycotic scalp infection caused by Microsporum canis is one of the more recalcitrant disorders, with increasing incidence during the last decade. We report our experience with administration of itraconazole in 163 children (86 girls, 77 boys) with M. canis tinea capitis. Fifty-five patients had previous treatment with terbinafine without success. In all children, the dosage of itraconazole was adjusted according to body weight, with 5 mg/kg/day given in a continuous regimen either as a capsule (116 patients) or an oral suspension (47 patients). In all children, there was both clinical and mycologic cure after a mean treatment period of 39 +/- 12 days (range 10-77 days). Eleven children (6.7%) had side effects: diarrhea in five children, cutaneous eruption in four, and abdominal pain in two. Itraconazole was effective and safe for the treatment of M. canis tinea capitis.

Administration, Oral↗
PubMed1991

Tinea corporis due to Microsporum canis from an asymptomatic dog.

The patient was a 19-year-old female student who purchased a puppy from a pet shop four weeks earlier. At the time of her first examination, an annular edematous erythema with adherent scales and vesicles surrounding its margin was seen on the left forearm. On direct examination of the vesicles, fungal elements were detected, and Microsporum canis was isolated. The puppy was a Pomeranian and was kept in the house at all times. No clinical lesions were seen on the puppy, and the Wood's lamp test was negative. However, M. canis was isolated from the animal by the hairbrush method. Symptoms disappeared after the patient was treated topically with terbinafine cream for three weeks. Although the dog received no treatment whatsoever, there was no evidence of the disease on the pet. Results of the hairbrush method performed on the pet two and three weeks later were negative, but, at five weeks, it was again positive. Human infection with M. canis from an asymptomatic dog was demonstrated in this case. Attention should be paid to preventing infections from animals without lesions.

Adult↗
PubMed2000

Detection of Microsporum canis in the skin scrapings and hairs of dogs with dermatophytosis based on sequences of the chitin synthase 1 gene.

In the present study, to confirm Microsporum canis infection rapidly, we detected the chitin synthase gene 1 (CHS1) gene of M. canis in the hair and skin samples of four dogs with dermatophytosis. Amplification of the DNAs in the four samples with CHS1 primers yielded fragments of about 620-bp. Nucleotide sequence analysis of the CHS1 gene fragments from samples and a reference strain of M. canis gene showed more than 99% similarity. The method presented in this study can rapidly detect the DNA of M. canis in skin scrapings, and we anticipate that it will be a useful microbiological tool for the diagnosis of M. canis infections in animals and humans.

Animals↗
PubMed1977

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.

Antifungal Agents↗
PubMed1978

Human infections with Microsporum gypseum in Denmark.

Ninety cases of Microsporum gypseum infection in Denmark during the period 1933-1977 are reviewed. The sex ratio, age distribution, and anatomical sites are started. A case of onychomycosis in a 1-year-old child is reported, and the cases of M. gypseum onychomycosis in the literature are reviewed.

Adolescent↗
PubMed1978

Human infections with Microsporum persicolor in Denmark.

The geographical and ecological spread of Microsporum persicolor is reviewed. It is concluded that M. persicolor is a zoophilic dermatophyte prevalent mainly in Europe and seldom reported as the cause of human infection. Twelve Danish cases of M. persicolor infection are described--their clinical features, mycological findings, and treatment. The localization of these fungal infections is reviewed on the basis of the present material and 58 cases from the literature.

Adolescent↗
PubMed1980

The dysgonic form of Microsporum canis in N.W. London.

An account is given of the occurrence in N.W. London of ringworm due to the dysgonic form of Microsporum canis in cats, dogs, and humans. The unusual morphology of the dysgonic strain is described as is the extraordinary lability of the fungus in culture. The distribution of cases in man and animals in the area is mapped. The clinical and epidemiological behaviour of the fungus, as illustrated by four family outbreaks, differs little from that of the typical strain. The origin of the dysgonic strain is unknown.

Animals↗
PubMed2005

Phenotypical and molecular characterization of Microsporum canis strains in north-east Brazil.

AIMS: This study investigated the possible correlation between the phenotypical and genotypical characteristics of Microsporum canis isolated from cats and dogs in north-east Brazil. METHODS AND RESULTS: The mycological study was conducted by direct microscopic examination and by fungal culture. Polymerase chain reaction-restriction enzyme analysis and random amplification of polymorphic DNA techniques were used for the genotypical analysis. The morphological analysis showed a considerable diversity of colonies as well as different morphologies of conidia, despite the M. canis strains having been isolated under the same conditions. However, the molecular analysis showed that all analysed strains are genetically similar. CONCLUSIONS: This study, based on phenotypical and molecular analysis, evidences the wide spectrum of phenotypical variations in M. canis in contrast to the stable genotypes of such dermatophytes. SIGNIFICANCE AND IMPACT OF THE STUDY: The findings of this study indicate that M. canis isolated from cats and dogs with dermatophytosis in north-east Brazil may be clones, well adapted to the conditions of this region, despite M. canis showing different morphological features.

Animals↗
PubMed2003

A recombinant 31.5 kDa keratinase and a crude exo-antigen from Microsporum canis fail to protect against a homologous experimental infection in guinea pigs.

A Microsporum canis recombinant 31.5 kDa keratinase and a M. canis crude exo-antigen were tested as vaccines in an experimental infection model in guinea pigs. Animals were vaccinated subcutaneously three times at two-week intervals with either the keratinase, the exo-antigen or the adjuvant alone. Cutaneous challenge was performed blindly. Both humoral and cellular-specific immune responses to M. canis antigens were evaluated every 14 days, while a blind evaluation of clinical lesion development and fungal persistency in skin were monitored weekly. Vaccination induced very high and significant (P < 0.01) antibody responses towards both antigens. High cell-mediated immune responses to both immunogens were also induced by vaccination. After challenge, however, scores reflecting the severity of dermatophytic lesions did not differ significantly between vaccinated and control groups at any time after challenge. These results suggest that, in the guinea pig, the induction of specific immune responses against the M. canis-secreted antigens used in this study are not protective against challenge exposure.

Animals↗
PubMed2004

Generalized Microsporum canis dermatophytosis in six Yorkshire terrier dogs.

Six Yorkshire terrier dogs with generalized, chronic dermatophytosis caused by Microsporum canis were seen over a 3-year period. Specific tests showed that they also had concurrent leishmaniosis (four cases), leishmaniosis and ehrlichiosis (one case) or diabetes mellitus (one case). Although specific therapy for these infectious diseases was instituted and the dogs were treated systemically and topically with appropriate antifungal drugs, only partial clinical resolution of the dermatophytosis was achieved. M. canis infection resolved in the dog with diabetes mellitus after stabilizing the diabetes mellitus. Although immunological studies were not performed in these cases, it is theorized that the immune disregulation caused by leishmaniosis, ehrlichiosis or diabetes mellitus may have favoured generalization of the infection and prevented favourable responses to appropriate treatment of the M. canis infection.

Animals↗
PubMed2004

Development of an in vitro, isolated, infected spore testing model for disinfectant testing of Microsporum canis isolates.

The isolated infected hair model is a commonly used technique to test the fungicidal efficacy of topical therapies against Microsporum canis. The most commonly used model uses mats of infective hairs, and results from various laboratories have differed. The objectives of this study were to develop a method to produce spores for testing when only mycelial forms were available and to develop a semiquantitative testing method that used only infective spores from hairs, and not pooled hair samples for testing. Ten isolates of M. canis were used in this study. Juvenile guinea pigs were easily infected using mycelial forms of M. canis and large numbers of spores were easily harvested for testing. Eight dilutions of disinfectants were tested. Fungal culture data were evaluated using an endpoint dilution at which there was 100% fungicidal activity, i.e. no growth on the plates. The 10 samples showed identical results. Chlorhexidine and Virkon(R) S were ineffective even when used at x4 the manufacturer's recommended dilution. Lime sulphur (1 : 33), enilconazole (20 microL mL(-1)), and bleach (1 : 10) were consistently effective when used at the recommended dilution. In addition, lime sulphur and enilconazole were 100% fungicidal even when the recommended concentration was diluted 1 : 4 or x4 as dilute as recommended.

Animals↗
PubMed2005

Development of an enzyme-linked immunosorbant assay (ELISA) for the serodiagnosis of canine dermatophytosis caused by Microsporum canis.

Abstract In dogs, dermatophytosis should be considered in any case of alopecic, papular or pustular lesion. The aim of this study was to develop an enzyme-linked immunosorbant assay (ELISA) as an aid in the diagnosis of canine dermatophytosis. The antigen used was a whole fungal extract obtained from an isolate of Microsporum canis cultured on a liquid medium from the parasitized hair of a cat with patches of alopecia. To assess the ELISA performances, sera from 18 dogs with dermatophytosis caused by M. canis (group A, n = 18), 20 dogs with skin diseases other than dermatophytosis and 22 healthy dogs (group B, n = 42) were tested. Four further animals were tested: three with dermatophytosis caused by M. gypseum and one by T. mentagrophytes. A significant difference (P < 0.01, Wilcoxon's test, w = 364) was found between IgG-specific levels of sera of recently M. canis-infected dogs (infection < 15 days) and controls (although three dogs had negative titres at this stage). A highly significant difference (P < 0.001, w = 462) was noted between controls and dogs with infection of longer duration (> 30 days). All dogs had positive titres at this stage. A highly significant correlation (P < 0.001, Spearman's test, rho = 0.86) between duration of infection and IgG concentration was noted. The test has good sensitivity (83.3%) and high specificity (95.2%) but some dogs retained positive titres after elimination of infection. The sensitivity is higher than that of direct microscopic hair examination and similar to that of fungal culture with DTM (dermatophyte test medium).

Animals↗
PubMed2007

Use of isolated infected spores to determine the sporocidal efficacy of two commercial antifungal rinses against Microsporum canis.

In this study, isolated infective Microsporum canis spores were used in an in vitro test model to compare the sporocidal activity of two commercial topical antifungal rinses. The two commercial test solutions used in the study were a lime sulphur solution 97.8% (LymDyp) and miconazole base 5.2%/chlorhexidine gluconate 5.9% mixture (Malaseb Concentrate Rinse). Water and household bleach were used as controls. Isolated infective spores were harvested from infected hairs and 500 microL of the spore suspension was incubated with an equal volume of dilutions of lime sulphur or the miconazole/chlorhexidine gluconate combination for 5 min and 4 h followed by fungal culture. There were too many to count colonies on the water control plates. Lime sulphur was 100% sporocidal at all test dilutions at both times. Miconazole/chlorhexidine gluconate was 100% sporocidal at all but the 1 : 128 dilution after 5 min of incubation and 100% sporocidal when incubated with spores for 4 h. It is not known if the two products have similar antifungal activity against infective spores on or within hairs; however, based on the findings of this study there is good evidence to recommend either rinse as an adjuvant topical therapy in a dermatophyte treatment and control program.

Administration, Cutaneous↗