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PubMed1992

Microsporum gypseum complex in man and animals.

Twenty-eight strains of the Microsporum gypseum complex isolated from humans and animals were studied. The perfect form was found for 25 of the isolates. Nannizzia incurvata was the species most frequently involved in human pathology, while Nannizzia gypsea was most frequently found on animal lesions. Nannizzia fulva was rarely involved pathologically and Nannizzia corniculata was not isolated during this study. It is surprising to note that this species was not found even though most of our strains (22/28) came from Africa. Reliable methods are not available for differentiating among the anamorphs, which are commonly called M. gypseum, Microsporum fulvum or Microsporum boullardii. The Sabouraud medium conventionally used for medical mycology makes almost no distinction among them. We found that the species could be easily distinguished by colonial and microscopic features when grown on Takashio medium. When strains are atypical, sexual reproduction remains the reference technique but, in most cases, Takashio medium makes it possible to avoid this long drawn-out procedure.

Adolescent↗
PubMed1978

[Current knowledge on imperfect and perfect forms of Epidermophyton, Microsporum and Trichophyton species].

The taxonomic status of the members of the form genera: Epidermophyton, Microsporum and Trichophyton is critically appraised. Two species of epidermophyton, 16 of Microsporum and 21 of Trichophyton are considered to be valid. Currently the perfect status of nine Microsporum and eight Trichophyton species have been described. They are respectively classified in the genera Nannizzia and Arthroderma. The value of the tester strains of the heterothallic perfect states in resolving taxonomic problems is discussed.

Epidermophyton↗
PubMed1984

Analytical isoelectric focusing of secreted dermatophyte proteins applied to taxonomic differentiation of Microsporum and Trichophyton species (preliminary studies).

Culture filtrates were prepared from dermatophytes under standard conditions and adapted for analytical isoelectric focusing in thin layer polyacrylamide gels over the pH range 3.5-9.5. Dermatophytes grown in trypticase soy broth secreted a large number of proteins displaying a wide range of isoelectric points (pIs). Trichophyton megninii extracts contained a triplet of proteins focusing in the pH 8.0-8.5 range that were absent in taxonomically related T. kuryangei isolates. Single ascospore isolates and standard tester strains of Nannizzia otae (+) mating type were differentiated from the (-) mating type by proteins focusing at pH 6.5 and 8.4. These were markedly reduced in the (+) type. The isofocused pattern of Microsporum canis conformed closely to the (-) mating type of N. otae. The protein patterns of T. megninii and T. kuryangei were distinct from those obtained with M. canis and M. equinum because of an intense-staining broad protein band, pI 7.2, and three periodic acid-Schiff-positive glycoproteins focusing in the acidic range which were absent in the Microsporum species. A characteristic protein or doublet (pI 8.7) was present in the Microsporum species and absent in the Trichophyton species. Analytical isoelectric focusing is a potentially useful method to distinguish inter- and intra-species differences in the pattern of secreted dermatophyte proteins present in culture filtrates and in trichophytins. The information derived may be useful in the classification of species.

Culture Media↗
PubMed1965

UPTAKE OF GRISEOFULVIN BY THE SENSITIVE DERMATOPHYTE, MICROSPORUM GYPSEUM.

El-Nakeeb, Moustafa A. (Rutgers, The State University, New Brunswick, N.J.), and J. O. Lampen. Uptake of griseofulvin by the sensitive dermatophyte, Microsporum gypseum. J. Bacteriol. 89:564-569. 1965.-Actively growing cultures of Microsporum gypseum took up large amounts of griseofulvin-(4-methoxy-H(3)) from the medium. Initially, most of the material could be extracted with hot water, but there was a continuing increase in firmly bound forms of the antibiotic. The fungus accumulated griseofulvin intracellularly to a level up to 100 times that present in the medium. The process appeared to involve two phases. A small amount of griseofulvin was bound almost instantaneously. This binding was independent of the culture conditions or cell viability. The second stage was prolonged and was governed by the different factors controlling active metabolism, but it proceeded in organisms whose growth had been inhibited by the antibiotic itself or by limited nutrients. This stage required a supply of metabolic energy, since it was temperature-dependent, needed an exogenous energy source, and was completely inhibited by sodium azide or 2,4-dinitrophenol. Uptake was optimal at pH 5.5 to 6.5. Synthesis of a transport system is probably required, since uptake is prevented by p-fluorophenylalanine. Heat-killed cells did not take up griseofulvin beyond the small amount bound instantly.

2,4-Dinitrophenol↗
PubMed1965

DISTRIBUTION OF GRISEOFULVIN TAKEN UP BY MICROSPORUM GYPSEUM: COMPLEXES OF THE ANTIBIOTIC WITH CELL CONSTITUENTS.

El-Nakeeb, Moustafa A. (Rutgers, The State University, New Brunswick, N.J.), and J. O. Lampen. Distribution of griseofulvin taken up by Microsporum gypseum: complexes of the antibiotic with cell constituents. J. Bacteriol. 89:1075-1081. 1965.-The griseofulvin-(4-methoxy-H(3)) accumulated by Microsporum gypseum was bound to fungal constituents. Mild procedures (hot-water or acetone extraction) removed between 40 and 60% of the total concentration of antibiotic. The remainder was recovered only after treatment with hot trichloroacetic acid followed by hot NaOH. The ratio of griseofulvin-H(3) in the water-soluble pool to that in the nucleic acid (soluble in hot trichloroacetic acid) and protein (soluble in NaOH) fractions was about 2:1:1, respectively. Only small amounts of radioactivity could be detected subsequent to hot-water extraction in the cold trichloroacetic acid extracts and in the cell-wall residues. Essentially all the activity in the soluble pool and in the nucleic acid extracts was chemically unchanged griseofulvin, much of which was present in various complexes, especially after long periods of incubation. One cannot be certain of the original form of all the radioactivity which was extracted in the protein fraction, because some degradation of the antibiotic occurred during the hot NaOH treatment. Nevertheless, a considerable amount of griseofulvin-H(3) was still present, and there had been no significant incorporation of radioactivity into the amino acid residues. It is probable, therefore, that the radioactivity in both protein and nucleic acid fractions represents complexes of the antibiotic with macromolecular components which were formed in vivo by the sensitive organisms.

Amino Acids↗
PubMed1993

Epidemiology of the dermatophytoses in the Florence area of Italy: 1985-1990. Trichophyton mentagrophytes, Epidermophyton floccosum and Microsporum gypseum infections.

Between 1985 and 1990 we observed 2085 cases of dermatophytoses in the Florence area of Italy. Trichophyton rubrum and Microsporum canis were the major etiological agents. 126 cases of dermatophytoses observed during this period were caused by Trichophyton mentagrophytes. Most of the patients came from rural areas or they kept pets. Epidermophyton floccosum ranked fourth in frequency (95 cases). The patients were adults and mainly males, most of whom engaged in sports or lived in group environments. Microsporum gypseum was isolated in 31 cases. Infections occurred directly from contact with soil or domestic animals. We report the principal clinical data concerning these last three dermatophyte infections.

Adult↗
PubMed2004

Population structure and evolutionary origins of Microsporum canis, M. ferrugineum and M. audouinii.

The recurrent evolutionary emergence of asexual lineages within sexual zoo- and anthropophilic dermatophyte species living in animal-frequented soil is likely to be triggered by changes in ecological niche, i.e., shifts of host animal. Subsequent adaptation to the new host species is noted. Sometimes geographic isolation or intrinsic host factors like human race may also play a role in speciation. In the present study, we elaborate concepts of speciation in dermatophytes using the Microsporum canis complex as an example. The group consists of a cluster of phylogenetically closely related anamorphs: the anthropophilic taxa Microsporum audouinii and M. ferrugineum, and the zoophilic taxon M. canis. The sexually reproducing species underlying this complex is Arthroderma otae. The study is done by an analysis of the population structure of about 200 isolates and using intergenic spacers, non-translated regions of genes as well as hypervariable microsatellite markers that are known to evolve at high mutation rates. The results suggest that sympatric speciation took place already during the period where mating ability was maintained and thus that strictly clonal fungal species emerged in Africa and led to genetically isolated clonal species elsewhere.

Alleles↗
PubMed1996

Unusual Microsporum canis infections in adult HIV patients.

Tinea capitis in men, even if infected with HIV, is infrequent. Microsporum species nail infections are extremely rare. In most cases Microsporum canis infection is usually easy to treat with antifungal agents. We describe two HIV-infected men with an unusual M. canis infection. Both patients had tinea capitis, presenting as alopecia in one and scaling of the scalp in the other. One patient also had tinea unguium caused by M. canis. Ketoconazole was ineffective in both patients; terbinafine was tried in one patient without benefit; itraconazole was effective in both, but treatment took many months and only one patient was cured.

Acquired Immunodeficiency Syndrome↗
PubMed2003

Species-identification of dermatophytes Trichophyton, Microsporum and Epidermophyton by PCR and PCR-RFLP targeting of the DNA topoisomerase II genes.

BACKGROUND: We have focused on the DNA topoisomerase II genes of pathogenic fungi and have previously applied polymerase chain reaction (PCR)-based identification of several species including the some of the major dermatophyte species. OBJECTIVE: To identify the dermatophytes (18 species) to a species level by PCR and PCR-restriction fragment length polymorphism (RFLP) techniques, without determining the nucleotide sequence. METHODS: The genomic DNAs of the dermatophytes (ten species of Trichophyton, seven species of Microsporum, and Epidermaphyton floccosum) were amplified by PCR using a common primer set (dPsD1) for the dermatophytes, followed by nested PCR using other primer sets (dPsD2, PsT and PsME) that contained primers specific for the DNA topoisomerase II genes of the dermatophytes. PCRs using PsT and PsME were used for the species-identification of Trichophyton, Microsporum and E. floccosum. The PCR products generated by dPsD2 were digested with restriction enzymes (Hinc II, Hinf, Afl II and PflM I), and the restriction profiles were analyzed. RESULTS: Of the eighteen species of dermatophytes, five species (T. rubrum, T. violaceum, M. canis, M. gypseum and E. floccosum) were specifically identified by the PCR using PsT and PsME to the species level, and the remaining species were identified by the unique restriction profiles for each species in the PCR-RFLP analysis, except that the restriction profile of T. mentagrophytes var. interdigitale was identical to that of T. mentagrophytes var. quinckeanum. CONCLUSION: PCR and PCR-RFLP techniques targeting the DNA topoisomerase II gene are simple and rapid, and quite useful as tools for the identification of dermatophytes to the species level.

DNA Topoisomerases, Type II↗
PubMed1999

Possible involvement of Ca2+/calmodulin-dependent protein kinase in the regulation of phospholipid biosynthesis in Microsporum gypseum.

The mechanism of action of Ca2+/calmodulin on phospholipid synthesis in Microsporum gypseum has been studied. These second messengers were observed to mediate their function through phosphorylation mechanism as altered protein kinase activity was seen in calcium/trifluoperazine (calmodulin antagonist) grown cells. The activity of protein kinase was dependent on calcium (200 microm) and calmodulin (1 microm). In vitro studies of phosphorylation and dephosphorylation in relation to phospholipid synthesis in Microsporum gypseum have been carried out. Addition of KN-62 (a specific inhibitor of Ca2+/calmodulin-dependent protein kinases) and polyclonal antibodies raised against purified Ca2+/calmodulin-kinase (CaMPK) of M. gypseum in the cell extract, leads to the inhibition in the incorporation of labelled acetate into total phospholipids in this fungus. These results suggest a possible involvement of Ca2+/calmodulin via Ca2+/calmodulin-dependent phosphorylation in phospholipid synthesis in M. gypseum.

Calcium↗
PubMed1999

Phylogenetic relation of Epidermophyton floccosum to the species of Microsporum and Trichophyton in chitin synthase 1 (CHS1) gene sequences.

The Nucleotide sequence of the chitin synthase 1 (CHS1) gene of Epidermophyton floccosum, an anthrophophilic dermatophyte which is the type species of the genus Epidermophyton was analyzed to determine its phylogenetic relation to eight other dermatophyte species belonging to the genera Microsporum and Trichophyton, which were sequenced in our previous studies. A genomic DNA fragment about 620 bp in length of the CHS1 gene was amplified from E. floccosum by polymerase chain reaction (PCR) and was sequenced. The CHS1 nucleotide sequence showed more than 85% similarity with sequences derived from the other dermatophytes. Phylogenetic analyses of the sequences from E. floccosum revealed that the genus Epidermophyton may be genetically distinct from Microsporum and Trichophyton.

Chitin Synthase↗
PubMed2003

High rate of Microsporum canis feline and canine dermatophytoses in Northeast Brazil: epidemiological and diagnostic features.

Over a one year period (November 2000-December 2001), clinical specimens from 189 dogs and 38 cats, from the city of Fortaleza, Ceará, Brazil, were examined at the Specialized Medical Mycology Center at the Federal University of Ceará to detect animals with dermatophytoses. The mycological analyses were conducted by direct microscopy and by fungal culture on Sabouraud agar, Sabouraud chloramphenicol agar and Mycosel agar. Dermatophytes were isolated from 27 of the 189 (14.3%) canine specimens and 14 of the 38 (36.8%) feline specimens. The identified dermatophytes were Microsporum canis (95%), M. gypseum (2.5%) and Trichophyton mentagrophytes var. mentagrophytes (2.5%). Microsporum canis was the most common species isolated (92.6% and 100%, for dogs and cats respectively). The percentage of positive direct microscopic examinations of clinical specimens and positive cultures was 61%. There was a high proportion of positive cultures from cats less than 1 year of age, but in dogs no significant differences were detected. There were no significant differences between the sexes. Dermatophytes were more frequently isolated in March, April and May, but no significant differences were detected in the seasonal distribution of canine and feline dermatophytoses.

Animals↗
PubMed1977

Microsporum magellanicum and Cunninghamella antarctica, new species isolated from Australic and Antarctic soil of chile.

Keratinophilic fungi were isolated from samples of soil collected in the extremity of Chile, in Southern Shetland and Antarctic continent. Two new species, Microsporum magellanicum and Cunninghamella antarctica are described. Microsporum magellanicum is characterized by verrucose or verruculose clavate macroconidia predominantly uniseptate, 4-87-2micronx14-4-21-6micron. Cunninghamella antarctica has conidiophores usually verticillately, pseudoverticillately and sympodially branched; and globose conidia with evident spines, 12-8-16micron in diameter.

Antarctic Regions↗
PubMed2002

Unusual presentation of Microsporum canis in human hair.

This study reports an unusual presentation of Microsporum canis in infected human hair in a three-year-old boy. Infected hairs showed ectothrix colonization with a mass of small conidia and numerous macroconidia typical of the genus Microsporum. The infected hairs also showed strong invasion by hyphae bearing small numbers of arthroconidia. These hyphae were thinner and longer than those normally found in hair and scalp. It is well known that in cases of tinea capitis due to M. canis, ectothrix arthroconidia formation is extrapilary and arises from intrapilary hyphae. In this case it seems that unusual quantities of hyphae were formed, and not all of them broke down into arthroconidia. They appeared to remain in the hair and to produce macroconidia, which were not formed outside the hair in contact with air, but instead seemed to remain in a deeper layer of the hair than the arthroconidia seen.

Child↗
PubMed2001

Cluster analysis of human and animal pathogenic Microsporum species and their teleomorphic states, Arthroderma species, based on the DNA sequences of nuclear ribosomal internal transcribed spacer 1.

We performed a cluster analysis of human and animal pathogenic Microsporum species and their teleomorphic states, Arthroderma species, including A. otae-related species (M. canis, M. audouinii, M. distortum, M. equinum, M. langeronii, and M. ferrugineum) and M. gypseum complex (A. fulvum, A. gypseum, and A. incurvatum) using DNA sequences of nuclear ribosomal internal transcribed spacer 1 (ITS1). The dendrogram showed the members of A. otae-related species to be monophyletic and to construct an extremely closely related cluster with a long horizontal branch. This ITS1-homologous group of A. otae was organized in 6 unique genotypes, while sequences of the members of the ITS1-homologous group of M. gypseum complex are more diverse. This ITS1-based database of Microsporum species and their teleomorphic states will provide a useful and reliable species identification system: it is time-saving (takes two to three days), accurate and applicable even to strains with atypical morphological features or in a non-culturable state.

Animals↗
PubMed1989

Fungal kerion--total scalp involvement due to Microsporum canis infection.

We report the case of a 5-year-old girl who developed a remarkably extensive kerion of the scalp due to Microsporum canis infection. Total scalp involvement of this severity and prolonged duration is now unusual, but there has been surprisingly little residual cicatricial alopecia. Microsporum canis does not respond well to ketoconazole, and griseofulvin remains the drug of choice for dermatophyte infections involving hair; a prolonged course may be necessary. This case also demonstrates the benefit of corticosteroids for certain cases of inflammatory ringworm where the host's response to the fungus is exceptionally marked.

Administration, Topical↗
PubMed2004

Efficacy of pre-treatment with lufenuron for the prevention of Microsporum canis infection in a feline direct topical challenge model.

Oral lufenuron is reportedly an effective treatment for some cats with dermatophytosis. The purpose of this study was to determine if lufenuron, when used as a pre-treatment prior to challenge exposure, would be protective against the development of infection after the direct topical application of fungal macrocondia (Microsporum canis spores). Three groups (n = 6/group) of juvenile cats were treated with either monthly oral lufenuron (30 or 133 mg/kg) or placebo. After 2 months of treatment, kittens were challenged using 10(5)Microsporum canis spores applied to the skin under occlusion. Cats were examined weekly and the following data collected: Wood's lamp examination; scoring for scale/crust, erythema and induration; lesion size; and the development of satellite lesions. Fungal cultures were performed bi-weekly. All cats became infected; the infections progressed, and then regressed, in a similar fashion in all groups. There were no consistent statistically significant differences in weekly infection scores between treated and untreated cats throughout the study. Treated cats did not recover faster than untreated cats. We conclude that oral lufenuron at the dosing schedule and conditions used in this study did not prevent dermatophytosis or alter the course of infection by direct topical challenge.

Animals↗