Exocellular enzyme activity of dermatophytes and other fungi isolated from ruminants in Southern Iraq

Sixteen fungal species were isolated from 182 specimens collected from four ruminants (buffalo, camel, cattle and sheep) in Southern Iraq. Fungi represented by five species of dermatophytes and eleven species of other fungi were screened for the activity of four enzymes; keratinase, proteinase, lipase and amylase. Keratinase was found to be produced by all of the dermatophytes and non-dermatophytes, except for Paecillomyces variottii and Scytalidium lignicola. However, high keratinase activity was expressed by the dermatophytic species particularly by Trichophyton mentagrophytes var. erinacei and Microsporum gypseum. Three dermatophytes viz. M. gypseum, T. verrucosum and T. mentagrophytes var. nodulare were capable of producing protease, lipase and amylase. Although, T. mentagrophytes var. erinacei showed high protease activity, it did not produce lipase and amylase. On the contrary most of the non-dermatophytic species revealed protease and lipase activities higher than the dermatophytes. The Curvularia spp. isolates showed the highest protease and amylase activity, while Aspergillus parasiticus revealed the highest activity of lipase and amylase. No correlation was observed between enzyme activity and the growth rate of the examined fungi. This revised version was published online in June 2006 with corrections to the Cover Date.     

In vitro susceptibility of dermatomycoses agents to six antifungal drugs and evaluation by fractional inhibitory concentration index of combined effects of amorolfine and itraconazole in dermatophytes

To investigate the antifungal drug susceptibility of fungi responsible for dermatomycoses, minimum inhibition concentration (MIC) tests were performed in 44 strains of dermatophytes, including Trichophyton rubrum, Trichophyton mentagrophytes, Trichophyton verrucosum, Trichophyton tonsurans, Microsporum canis, Microsporum gypseum and Epidermophyton floccosum, with six antifungal drugs (amorolfine, terbinafine, butenafine, ketoconazole, itraconazole and bifonazole) by broth microdilution assay according to Clinical Laboratory Standard Institute protocols. Six possible dermatomycosis‐causing non‐dermatophytic fungi were also tested. The two major causes of tinea, T. rubrum and T. mentagrophytes, showed significantly different sensitivities to ketoconazole and bifonazole. Clinically derived dermatophytes were sensitive to the six antifungal drugs tested. However, non‐dermatophytes, especially Fusarium spp., tended to be resistant to these antifungal drugs. In Trichophyton spp., the MICs of non‐azole drugs had narrower distributions than those of azoles. To evaluate the effects of antifungal drug combinations, the fractional inhibitory concentration index was calculated for the combination of amorolfine and itraconazole as representative external and internal drugs for dermatophytes. It was found that this combination had synergistic or additive effects on most dermatophytes, and had no antagonistic effects. The variation in susceptibility of clinically derived fungal isolates indicates that identification of causative fungi is indispensable for appropriately choosing effective antifungal drugs in the early stages of infection. The results of combination assay suggest that multiple drugs with different antifungal mechanisms against growth of dermatophytes should be used to treat refractory dermatomycoses, especially onychomycosis.     

Eastern Cottontail (<Emphasis Type="Italic">Sylvilagus Floridanus)</Emphasis> as Carrier of Dermatophyte Fungi

Eastern cottontail (Sylvilagus floridanus, fam. Leporidae), introduced into Piedmont (Italy) in the 1960s, was studied as carrier of dermatophyte fungi. Of 216 hair samples collected from animals culled between September 1999 and July 2000 in the Province of Alessandria (Piedmont, Italy) during a pest control project, 57 (26.4%) yielded dermatophyte colonies. As two different species of dermatophytes grew from two samples, a total of 59 fungal isolates (26.5%) were obtained. Six dermatophyte species both geophilic (M. gypseum, M. cookei, Trichophyton ajelloi, T. terrestre) and zoophilic (M. canis, T. mentagrophytes) were identified. No sex-related differences were found but season-related differences were observed. The highest prevalence of dermatophyte-positive samples was recorded in May–September, due to the geophilic fungi whose prevalence decreased during colder and increased during warmer months ( p < 0.001). The presence of zoophilic dermatophytes, T. mentagrophytes, commonly associated with rodents, small mammals and lagomorphs and M. canis, usually correlated with domestic environment, did not change the whole year round. As Eastern cottontail has been showed to be a carrier of dermatophytes transmissible to man (M. canis, T. mentagrophytes and M. gypseum), it may represent a source of infection for gamekeepers, hunters and veterinarians.     

Keratinophilic fungi isolated from children's sandpits in the Nablus area,West Bank of Jordan

The keratinophilic fungi of 29 sandpits from kindergarten schools and public parks in the city of Nablus was analysed to evaluate their role in the epidemiology of diseases caused by these fungi. Seventy two species were recovered 28 of which were common to both kindergartens and public parks sandpits. High percentage (57.4%) of fungal isolates found had been identified as the causes of various types of mycoses. Eight species of dermatophytes and closely related fungi were recovered, of which the followings were the most commonly found species in sandpits: Chrysosporium keratinophilum (20.7%), Microsporum gypseum (17.2%), Trichophyton mentagrophytes (6.9%), and C. evolceanui (6.9%).     

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 from 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 byMicrosporum cookei (21.7 %) and thenTrichophyton 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.     

Chicory extracts from Cichorium intybus L. as potential antifungals

In this work extracts from roots of the common vegetable Cichorium intybus L., highly appreciated for its bitter taste, were studied to investigate their possible biological activity on fungi from a variety of ecological environments: some are parasites on plants (phytopathogens) or of animals and humans (zoophilic and anthropophilic dermatophytes), others live on the soil and only seldom parasitize animals (geophilic dermatophytes). The extracts were ineffective on geophilic species and on tested phytopathogens, with the exception of Pythium ultimum, whereas they inhibited the growth of zoophilic and anthropophilic dermatophytes, in particular Trichophyton tonsurans var. sulfureum, whose treatment caused morphological anomalies, here observed by scanning electron microscopy. This behaviour is discussed on the basis of the presence in the chicory extract of the two main sesquiterpene lactones, 8-deoxylactucin and 11β,13-dihydrolactucin.     

Antimicrobial agents

In the microbial degradation of Fungicidin by lower pathogenic fungi, no significant differences were found in the rate of its degradation by the various species of dermatophytes employed (Trichophyton mentagrophytes, Trichophyton rubrum andMicrosporum gypseum), but there was a marked difference in the rate of enzymatic degradation by microorganisms adapted and not adapted to Fungicidin or Amphotericin B. After four hours' degradation of Fungicidin by non-adapted strains, about 70% of the Fungicidin in the medium was still intact, whereas it was completely degraded by adapted strains during the same interval. The addition of protein biosynthesis inhibitors (chloramphenicol and tetracycline) and of the antifungally active substance 2-aminotridecane did not influence the microbial degradation of Fungicidin by dermatophytes.     

In vitro activity of seven azole compounds against some clinical isolates of non-dermatophytic filamentous fungi and some dermatophytes

The in vitro activity of seven azole compounds viz clotrimozole, isoconazole, bifanazole, fluconazole oxyconazole, Bay n 7133 and Bay L 9139 was investigated against 47 clinical isolates of pathogenic non-dermatophytic filamentous fungi and dermatophytic fungi. The isolates included Hendersonula toruloidea-26, Scytalidium hyalinium-5, Scytalidium japonicum-1, Trichophyton rubrum-5, Trichophyton tonsurans-3, Trichophyton mentagrophytes var. mentagrophytes-4, Epidemophyton floccosum-2, Microporum gypseum-2 isolates. The drugs were significantly more active against the dermatophytes (MIC range 0.025–1.56 g/ml) than non-dermatophytes (MIC range 0.39–6.25 g/ml). Isoconazole showed more activity than the rest of the azole compound tested. Clotrimazole, fluconazole, oxyconazole, bifonazole were comparable in their inhibitory activity against both dermatophytes and non-dermatophytes. The azole derivatives, Bay n 7133 and Bay L 9139 showed higher MIC range i.e. gave a range of 0.39–1.56 g/ml for dermatophytes and 1.56–6.25 g/ml for non-dermatophytic filamentous fungi. The minimal fungicidal concentration (MFC) of all the drugs tested were mostly within 2–8 times their MIC values.     

Stoffwechselprodukte von Mikroorganismen

Zusammenfassung Das Steroidantibioticum Fusidinsäure wurde in Kulturen von sechs Dermatophyten und vonCalcarisporium antibioticum, einer neubeschriebenen Art der Deuteromycetes, nachgewiesen. Das Vorkommen von Antibiotica bei Dermatophyten und das Spektrum der Fusidinsäure bildenden Pilze werden erörtert.

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Metabolic products of microorganisms71. Fusidic acid from dermatophytes and other fungi

Summary The steroid antibiotic fusidic acid was identified from six strains of dermatophytes and fromCalcarisporium antibioticum, a newly described species of the imperfect fungi. Antibiotic formation by dermatophytes and production of fusidic acid by fungi are discussed.

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70. Mitteilung:W. Crueger u.H. Zähner: Arch. Mikrobiol.63, 376 (1968).     

Fungal infections of the nails in Western Australia

Between 1963 and 1972, 986 fungi were isolated from the nails of patients in Western Australia. Three clinical types of infections in both finger and toe nails were studied. All 3 types occurred more commonly in adults over the age of 20. Multiple infections were relatively frequent. Two hundred and fourteen of the nail infections were caused by dermatophyte fungi.Trichophyton rubrum was the predominant aetiologic agent isolated from both finger and toe nails,T. mentagrophytes and other dermatophytes were involved to a lesser degree. Paronychia of the finger nails was common and mainly caused byC. albicans. Aspergillus species were the most frequent fungi grown from superficial white onychomycosis.     

Incidence of dermatophytes and cyclohexamide resistantfungi on healthy children hairs and nails in nurseries

In order to estimate the prevalence of dermatophytes and other fungi on healthy children hairs and nails, 92 hair samples and 85 nail samples (groups of 10 finger nails from each child) were collected from 5 nurseries (children aged 9 months up to 4 years) in Assiut city. From hair samples 22 species were collected, Trichophyton (2 species) and Microsporum (2 species) were the only recovered dermatophytes in addition to well known keratinophilic genus Chrysosporium (4 species). From nail samples, 18 species were identified, Trichophyton was represented by 4 species, Microsporum, 2 species and Chrysosporium, 4 species. Also, several other saprophytes and cycloheximide resistant fungi were isolated. This revised version was published online in June 2006 with corrections to the Cover Date.     

The isolation of keratinophilic fungi from African soils

Summary Twenty-seven soil samples from Kenya and 9 from Egypt were investigated for the presence of keratinophilic and pathogenic fungi. No systemic pathogenic fungi was obtained, while a total of 25 dermatophytes belonging to four species was isolated. The majority of the Kenya isolates belonged toM. gypseum, while Egyptian isolates belonged toT. mentagrophytes. Shady sites frequented by humans or animals produced higher incidences of dermatophytes in Kenya than those of the unshady isolated areas.     

Keratinophilic fungi inhabiting floor dusts of student houses at the South Valley University in Egypt

Keratinophilic fungi include true fungi that vigorously degrade keratin as well as a number of important human pathogenic dermatophytes. We identified 41 species and one variety belonging to 19 genera in 50 floor dust samples following culture on Sabouraud’s dextrose agar medium at 28°C. Dermatophytes and closely related fungi were represented by six species—Aphanoascus fulvescens, Aphanoascus sp., Arthroderma cuniculi, Chrysosporium lucknowense, Gymnoascus uncinatus and Trichophyton rubrum. There were 35 species and one variety of other fungal species, with members of Aspergillus and Penicllium being the most prevalent. Twenty-seven species and 1 variety belonging to 14 genera were identified from 24 dust samples gathered at 2-week intervals from male student housing at El-Kenose during January–December 2005 that had been cultured on Sabauraud’s dextrose agar at 28°C. The monthly counts of keratinophilic fungi showed irregular fluctuations, with a peak in April and the lowest point in November. Dermatophytes and closely related fungi were represented by Aphanoascus fulvescens, Aphanoascus sp., Chrysosporium lucknowense, Gymnoascus uncinatus, and Trichophyton rubrum. In conclusion, the study reports the incidences of some dermatophytes found in the floor dust of student houses of South Valley University, Egypt.     

Onychomycosis in Rome,Italy

This report presents the results of a study conducted between 1985 and 1994 on onychomycosis observed in the city of Rome. Six thousand six hundred and eighty eight patients were examined during this period. Among them 1,762 (26.3%) were affected by fungal nail infections. Because the etiologic agents could not be isolated in 105 cases (6%), the results refer to 1,657 subjects (24.8% of the total), presenting with positive microscopic and cultural examinations. Thirty eight patients (2.3%) had onychomycosis of both their hands and feet.From an etiological point of view, 59.1% of the nail infections were caused by yeasts, 23.2% were infected with dermatophytes and 17.6% by non-dermatophytic fungi. The etiology of onychomycosis of the hands differed from that of the feet. Yeasts were primarily responsible for onychomycosis of the hands (86.2%), while dermatophytes caused tinea unguium peduum (48%). Fungal fingernail infections by Candida spp. were the most common (50.3%), followed by those of the feet by dermatophytes (20%). Candida albicans was responsible for 70.6% of the hand infections but for only 15.9% of those of the feet. Trichophyton rubrum and T mentagrophytes were the most common dermatophytes, mainly causing toenail infections (23.4% and 21%, respectively), while Aspergillus spp., Scopulariopsis brevicaulis, Acremonium spp. and Aspergillus niger were the most common non-dermatophytes observed.With regard to sex, the fungal nail infections were more widespread in women (72.1%) and in subjects of both sexes over the age of 50.     

In vitro characterization of Trichophyton rubrum and T. mentagrophytes biofilms

Dermatophytes are fungi responsible for a disease known as dermatophytosis. Biofilms are sessile microbial communities surrounded by extracellular polymeric substances (EPS) with increased resistance to antimicrobial agents and host defenses. This paper describes, for the first time, the characteristics of Trichophyton rubrum and T. mentagrophytes biofilms. Biofilm formation was analyzed by light microscopy, scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) as well as by staining with crystal violet and safranin. Metabolic activity was determined using the XTT reduction assay. Both species were able to form mature biofilms in 72?h. T. rubrum biofilm produced more biomass and EPS and was denser than T. mentagrophytes biofilm. The SEM results demonstrated a coordinated network of hyphae in all directions, embedded within EPS in some areas. Research and characterization of biofilms formed by dermatophytes may contribute to the search of new drugs for the treatment of these mycoses and might inform future revisions with respect to the dose and duration of treatment of currently available antifungals.     

Exoantigen tests for the immunoidentification of fungal cultures

Exoantigen tests for the immunoidentification of fungal pathogens are playing a new and significant role in the diagnostic laboratory. Properly performed and controlled exoantigen tests lead to rapid, accurate identification of cultures of many fungal pathogens. The tests are particularly valuable in identifying dimorphic pathogens that are difficult to convert or with atypical cultures. We review the value of exoantigen tests for identifying mycelial form fungi: Aspergillus spp. Blastomyces dermatitidis, Coccidioides immitis, Exophiala jeanselmei, Histoplasma spp., Paracoccidioides brasiliensis, Penicillium marneffei, Pseudallescheria boydii, Sporothrix schenckii, Wangiella dermatitidis and certain dermatophytes. We discuss procedures for performing the tests and sources of error.     

Keratinolytic and keratinophilic fungi of children's sandpits in the city of Turin

Soils rich in keratinic residues constitute a permanent or occasional reservoir for dermatophytes and keratinolytic and keratinophilic fungi, and are a source of potential infection for man and animals.The keratinolytic and keratinophilic mycoflora of 28 sandpits in Turin was studied to evaluate the risk of fungal skin infections that is run by children as they play in public parks and to lay the ground-work for a next epidemiological study of soil- and animal-inhabiting dermatophytes found in cities, and their impact on human dermatophytoses. Fifty seven species were isolated and a high percentage (52%) showed keratinolytic activity. Species of Microsporum, Trichophyton, Mariannaea, Aphanoascus, Chrysosporium, Malbranchea and Geomyces showed the most active keratinolysis.Work n. 315 performed under the auspices of the Centro di Studio sulla Micologia del Terreno del C.N.R. at the Dipartimento di Biologia vegetale dell Università di Torino.     

Species diversity of keratinophilic fungi in various soil types

Keratinophilic fungi are a highly specialized, keratin-degrading ecological group. They live in natural environments, mostly in the keratinrich remains of dead animal in the soil. We investigated species diversity in four types of soils with different physico-chemical properties. The strain material was identified based on morphological characters. Different representatives of Chrysosporium and geophilic dermatophytes dominated depending on soil pH. Geophilic dermatophytes were represented by one species, Trichophyton ajelloi, and the Chrysosporium group was represented by Chrysosporium keratinophilum. The frequency of Trichophyton ajelloi increased with an increase in pH, and it reached the maximum in strongly acidic soil (podzol), unlike the Chrysosporium group. The frequency of Chrysosporium keratinophilum was positively correlated with the content of humus, nitrogen, CaCO₃ and phosphorus in the soils.     

The fungistatic activities of vitamin K on dermatophytes

Summary and conclusions Four commercial preparations of vitamin K were evaluated for their fungistatic activities on the following dermatophytes:Microsporum canis, Epidermophyton floccosum, Trichophyton mentagrophytes, andTrichophyton Schönleinii.Table 1 lists the maximum nonfungistatic and the minimum fungistatic concentrations of each vitamin K.The fungistatic activities of the vitamins K are higher in the liquid than in the solid medium.VitaminIV was the most active on all the dermatophytes in both, the solid and the liquid medium. The fungistatic activities of the other vitamins K vary, in each medium, according to the dermatophyte. Sodium bisulfite decreases the fungistatic activities of vitamin K. Epidermophyton floccosum was the most sensitive to all the vitamins K used.