Mating patterns of dermatophytes of diverse origin in India

The mating patterns of Trichophyton mentagrophytes var. interdigitale (74 isolates) and the Microsporum gypseum complex (17 isolates) of diverse origin and T. rubrum (25 isolates) and T. tonsurans (10 isolates) of clinical origin were studied. The results of the study showed that the teleomorph of the Indian isolates of T. mentagrophytes belong to Arthroderma vanbreuseghemii, undetermined teleomorphs of T. mentagrophytes var. interdigitale (+) mating types, and undetermined teleomorphs of T. mentagrophytes var. interdigitale indeterminate mating types. All the isolates of T. rubrum and T. tonsurans were found to be of the (-) mating type.     

Sur l'état actuel des dermatophytes en Roumanie

Summary The actual state of dermatophytes in Romania is briefly reviewed. From the 20 species discovered, up to now, 14 belonged to the group of human and animal origin, the other 6 to geophilic dermatophytes.The most frequently isolated wereT. mentagrophytes, (var.interdigitale),M. audouinii, T. violaceum andT. rubrum, which altogether caused more than 50 % of the human ringworm found in the last 15 years.WhileT. mentagrophytes still remains the agent no. 1 of tinea pedis in Romania andT. rubrum keeps the first place in the nail involvements by dermatophytes, the first organism of tinea capitis areM. audouinii andT. violaceum, the former causing mainly the epidemic foci. Such epidemics may also be due toT. ferrugineum. The number of cases byT. schönleinii is more and more reduced. The infections byT. verruccosum are increasing. The rarity of cases due toT. gallinae, toT. equinum and toT. mengninii are pointed out.From the so called geophilic dermatophytes,M. gypseum, K. ajelloi andChrysosporium keratinophilum are mostly isolated from the Romanian soil.T. terrestre, T. evolceanui, T. indicum andM. cookei are infrequently found. A few isolates ofT. mentagrophytes andT. quinckeanum were also discovered in the soil.     

Equine ringworm due to Trichophyton mentagrophytes var. quinckeanum

Summary T. mentagrophytes var.quinckeanum was isolated from a case of equine tinea and this finding is thought to be unique. Although it is considered that the fungus is closely related toT. mentagrophytes, the small differences in the relative pathogenicity for animals and man, the unusual clinical pattern which can be seen, and the downy nature of primary isolates on Sabouraud's medium are features not to be expected withT. mentagrophytes infections. The ability of this fungus to produce green fluorescence in the hairs of infected guinea pigs is felt to be its most unique feature and warrants its separate identity asT. mentagrophytes var.quinckeanum.     

Relationship Between Phenotypic and Genotypic Characteristics of <Emphasis Type="Italic">Trichophyton mentagrophytes</Emphasis> Strains Isolated from Patients with Dermatophytosis

According to epidemiological, clinical and mycological criteria, it has long been admitted that the Trichophyton mentagrophytes species includes two varieties: a zoophilic variety (var. mentagrophytes) and an anthropophilic variety (var. interdigitale) that involve the upper and the lower part of the body, respectively. The further application of molecular techniques to the characterization of dermatophyte strains showed that this classification is unreliable. The aim of our study was to assess the usefulness of PCR–RFLP (restriction fragment length polymorphism) and sequencing in the characterization of T. mentagrophytes strains taken from Tunisian patients. The study was carried out in 2008 in the laboratory of Parasitology–Mycology of Farhat Hached University Hospital, Sousse, Tunisia. A total of 133 strains were isolated from 133 patients addressed to the laboratory for dermatological lesions very evocative of dermatomycosis. Eighty strains were isolated from lesions located on the lower part of the body (onychomycosis, tinea pedis) and 53 strains from the upper part of the body (tinea capitis, tinea corporis). All strains were submitted to mycological examination (direct microscopic examination and culture on Sabouraud medium) and further investigated by using RFLP analysis of the PCR-amplified ITS1-5.8 s-ITS2 region of the ribosomal DNA and the MvaI restriction enzyme. In addition, 62 strains were further submitted to a sequencing of the ITS1-5.8 s-ITS2 region. On the basis of mycological criteria, all strains were diagnosed as T. mentagrophytes. All strains produced the same RFLP pattern and were identified as T. mentagrophytes interdigitale regardless of the location of lesions. Out of the 62 sequenced strains, 16 were found anthropophilic and 46 were zoophilic. In conclusion, all strains provisionally diagnosed as T. mentagrophytes on the basis of mycological criteria were shown to belong to T. interdigitale by using PCR–RFLP and sequencing irrespective of the site of lesions. The predominance of zoophilic strains needs further investigation.     

Morphological changes of trichophyton mentagrophytes under the influence of increased carbon dioxide tension

Summary Growth pigment production as well as macroconidia and arthrospore formation ofTrichophyton mentagrophytes are stimulated under the influence of increased carbon dioxide tension. Macroconidia with spirals and pistol forms of macroconidia are observed.The granular form ofT. mentagrophytes displays an asteroid growth (Dextrose agar of Sabouraud) with an ingrowth and elongation of the ray branches in the agar and a decrease of the air-mycelium. The culture completely resembles to those ofT. mentagrophytes varasteroides. The macroconidia appear elongated and they acquire an asteroid arrangement. The less granular strains ofT. mentagrophytes take the appearance ofT. interdigitale type.An analogy is made between these morphogenetic changes under the effect of increased CO₂ tension in vitro and the influence of the animal organism in the evolution of the growth forms of dermatophytes in vivo in the process of their parasitic adaptation.     

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.     

Multicenter study of dermatophyte distribution in the metropolitan area of Barcelona (Catalonia,Spain)

The results of a multicenter study on the distribution of dermatophyte species in the metropolitan area of Barcelona (Spain) are presented.In the period 1977–1983, 638 dermatophyte strains were isolated from tineas by three different mycological laboratories. Zoophilic strains were prevalent comprising 64.4% of the isolates. T. mentagrophytes var. granulosum was isolated in 51% of the cases.A signigicant drop in the prevalence of T. tonsurans and T. violaceum was noted. Important variations were observed in dermatophyte distribution in relation to other geographical areas of Spain.     

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.     

Onychomycoses in a Military Population in Brazil

Purpose of Review

This study aimed to isolate and characterize filamentous fungi onychomycosis agents in a military population assisted at a hospital outpatient clinic.

Recent Findings

In onychomycosis, the fungi colonize the subungual region causing thickening, discoloration, or cracking of the nail bed. Samples were collected from patients with clinical sights of onychomycosis.

Summary

Among 80 samples collected, 50 (62.5%) had positive culture. Isolated dermatophytes (86%) were Trichophyton rubrum (21; 42%), T. mentagrophytes var. interdigitale (19; 38%), and Microsporum gypseum (3; 6%) and non-dermatophyte molds were Fusarium spp. (1; 2%), Scytalidium spp. (1; 2%), and Chaetomium globosum (5; 10%). Minimal inhibitory concentrations (mg/L) of terbinafine, itraconazole, and fluconazole necessary to inhibit 50/90% of the isolates were respectively 0.015/0.06, 0.06/0.12, and 32/32. Etiological agents of onychomycosis in a military hospital are similar as reported in studies for the general population. High prevalence of non-dermatophytic agents was observed, especially for Chaetomium globosum.

     

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.     

Degradation of keratin substrates by fungi isolated from sewage sludge

Four fungal species including two dermatophytes and two saprophytes were isolated from sewage sludge samples at Basrah (Iraq) they were tested for their degradative ability towards three types of keratin substrates (human hair, chicken feathers and wool). The rate of keratin degradation was expressed as weight loss over three weeks of incubation using a liquid culture medium. Human hair had the highest degradation rate by colonization of Chrysosporium pannicola and Microsporum gypseum at a rate of 62% and 4% respectively. Chicken feathers were highly degraded by Aspergillus flavus (32%) while wool degradation was highest by C. pannicola (45.5%) and Trichophyton mentagrophytes var. erinacei (38%). There was a significant difference (p < 0.00l) in keratin substrate degradation rates by the examined fungi. Keratinase activity was highest for C. pannicola and M. gypseum in the culture medium baited with human hair. Aspergillus flavus revealed the highest activity of this enzyme in cultures amended with chicken feathers while T. mentagrophytes var. erinacei showed highest keratinase activity in cultures with wool substrate. The amount of protein released into the culture medium varied among the tested fungi. The medium's alkalinity increased over incubation time from 6.5 to 7.8. Microscopic examination showed maceration of the keratin substrates by the fungi. This revised version was published online in June 2006 with corrections to the Cover Date.     

Isolation of zoosporogenous actinomycetes from desert soils

We have undertaken a study to estimate the species diversity of zoosporogenous actinomycetes that can be isolated from an arid environment. The study site encompassed an area of approximately 22 000 square kilometers of the Mojave Desert along the California-Nevada border. A series of 29 soil samples was collected along two intersecting transects of approximately 190 and 240 km which traversed a number of distinct ecosystems. A₀ horizon soils were collected from the rhizosphere of the predominant vegetation at each sampling site and screened for the target genera using selective isolation techniques: chemoattraction (xylose and -collidine) and baiting with hair. Following incubation of primary isolation plates for 28 days at 28°C, all colonies that exhibited filamentous growth, presence of sporangia and/or motile spores upon direct microscopic observation (450 and 1000×) were further characterized by fatty acid analysis (FAME). Most of the isolates fell into three broad clusters that roughly correlated with presumptive genus assignments. Individual isolates could be assigned to 226 FAME biotypes based on chromatographic similarity (85%). The dominant species (514/826 isolates) belong to a previously undescribed taxon that morphologically resemblesGeodermatophilus but possesses unique FAME profiles that include at least three novel lipids. The remainder of the isolates were species ofActinoplanes, indeterminate species or vagrant isolates ofStreptomyces.     

Changes of Dermatophytoses in Southwestern Greece: An 18-Year Survey

The isolation and distribution rate of dermatophytes as causative agents of superficial mycoses of skin, hair, and nails during an 18-year period (1991–2008) at a university hospital are presented. A comparative analysis of epidemiological differences within the first (1991–1999) and the second 9-year period (2000–2008) was performed. Skin scrapings, nail, and hair specimens were examined by a direct microscopic examination and culture. Identification of dermatophyte species was based on macroscopic and microscopic characteristics of colonies. During the complete period (18 years), 5,971 patients with suspected dermatophytosis were examined. Seven hundred and sixty-nine patients (12.8%) were found positive. Among them, 495 cases (64.3%) were of skin dermatophytoses, 91(11.8%) of hair, and 183 (23.7%) of nails. The most frequent etiological agents were Microsporum canis (54%), Trichophyton rubrum (38%), and T. mentagrophytes (6%). Epidermophyton floccosum, T. tonsurans, T. violaceum, and M. gypseum were responsible only for 16 cases (2%) of dermatophytoses. The prevalence of dermatophytoses seems to decrease significantly from 16.2% (1991–1999)–9.6% during the last 9-year period. The most frequent dermatophyte, M. canis, shows decreasing trends during the last period (from 58.5 to 45.7%), whereas T. rubrum shows an increasing isolation rate (from 35 to 43.6%), respectively. The most common form of dermatophytosis among children remains tinea capitis due to M. canis. The most frequent etiological agent of tinea unguium (81%) is T. rubrum.     

Repeated Ubiquitin Genes in Trichophyton mentagrophytes

Using Trichophyton mentagrophytes cDNA as a template, we performed PCR amplification with the UB1S and UB1R primers for isolation of a partial fragment of T. mentagrophytes ubiquitin gene. We screened the T. mentagrophytes cDNA library prepared with Uni-ZAP phage vector by hybridization with the T. mentagrophytes ubiquitin fragment, UB1S-UB1R. The nucleotide and deduced amino acid sequences of T. mentagrophytes ubiquitin gene encoded two ubiquitin repeats in 162 bp to 624 bp. The deduced amino acid sequences of ubiquitin from T. mentagrophytes shared about 98% similarity with those of Saccharomyces cerevisiae, Neurospora crassa, and Cryptococcus neoformans. Received: 28 April 1999 / Accepted: 22 June 1999     

Differentiation of trichophyton rubrum from trichophyton mentagrophytes

Conclusions Of the several morphological and physiological criteria that have been proposed to identifyTrichophyton rubrum andTrichophyton mentagrophytes differentially, only the hair invasion test agrees with the immunological results reported here.A typical strain ofT. rubrum andT. mentagrophytes was obtained from the Centraalbureau voor Schimmelcultures (Netherlands) and was used as reference strain. All isolates that did not invade hair shafts (in vitro) and that produced three precipitate lines in agargel diffusion tests against anti-T. rubrum serum (refence strain, Tr-1) were placed in one group. These isolates all also produced a red undersurface pigment and macroconidia with long parallel sides. They were labledT. rubrum.Other isolates that did invade hair shafts, and produced only two precipitate lines against anti-T. rubrum serum were placed in another group and were labeledT. mentagrophytes. These isolates had variable characteristics of pigment production, colony and conidial morphology.The antigenic studies thus corroborate the validity of the hair invasion test. The hair invasion test will probably remain in wider use because of its simplicity.     

Identification and genetic homogeneity of Trichophyton tonsurans isolated from several regions by random amplified polymorphic DNA

Trichophyton tonsurans is an anthropophilic dermatophyte mostly causing tinea capitis and tinea corporis. This study was carried out to identify T. tonsurans and to clarify whether it has any genetic differences depending on the phenotype or region of isolation by random amplified polymorphic DNA (RAPD) analysis with three random primers. The assay was performed in 11 Korean, 2 Japanese, 2 Taiwanese, 5 Brazilian and 1 American isolates of T. tonsurans together with the other 10 anamorphic species of dermatophytes and 3 Arthroderma spp. All tested species of dermatophytes showed distinct bands and T. tonsurans was differentiated from other dermatophytes. It was most clearly ifferentiated from T. mentagrophytes by using primer 5-GAAGGCTCCC-3 (OPAO-15). No difference was found in RAPD band patterns in all strains of T. tonsurans with these random primers. It was considered that T. tonsurans is a genetically homogeneous species regardless of its isolation regions, morphologic or physiologic characteristics.This revised version was published online in October 2005 with corrections to the Cover Date.     

Occurrence ofVibrio and other bacteria on the sea nettle,Chrysaora quinquecirrha

Sixty-two specimens of the sea nettle,Chrysaora quinquecirrha, were caught in the lower Chesapeake Bay, homogenized, and samples plated on a yeast extract-Bay water agar. Bacterial colonies were selected randomly, purified, and tested for 180 characteristics. Computer analysis permitted clustering of the 208 isolates into 15 groups (comprised of 133 strains) plus 75 nongrouped strains which failed to associate with any group at the 70% similarity level. The majority of the isolates (68.8%) wereVibrio species. These included 110 of the grouped strains (forming 12 of the 15 groups) and 33 of the nongrouped strains. The remainder of the isolates were distributed as follows:Pseudomonas (11.6%),Bacillus (8.2%),Flavobacterium (2.4%),Acinetobacter (2.4%),Moraxella (1.9%),Cytophaga (1.9%), Gram-positive cocci (1.4%), and miscellaneous (1.4%). All theBacillus were isolated from a group of moribund nettles and reflect an abnormal condition.Vibrio species predominated in the five catches of healthy nettles, but were distinctly different for each catch.     

Plantlet regeneration from mesophyll protoplasts ofBetula platyphylla var.japonica

Summary InBetula platyphylla var.japonica, colonies were induced efficiently from mesophyll protoplasts cultured in half strength MS (1/2MS) liquid medium containing 0.6 M mannitol, 0.09M sucrose and 1 M 4-PU and 1 M NAA at a cell density of 5 × 10⁴/ml. The colonies grew actively and developed into callus after 3 months of culture.Roots differentiated from the protoplast-derived white calluses cultured on the 1 /2MS solid media supplemented with 0.1–1 M 4-PU and 1 M NAA, and 10 M zeatin with no supplementation of NAA. Furthermore, the protoplast-derived green callus differentiated shoots with 1/2MS solid medium containing 1 M 4-PU or 10 M zeatin with no supplementation of NAA. When shoots obtained were cultured on the cytokinin-free MS solid medium with 2.5 M IBA and 0.1 M NAA, they rooted and developed into plantlets after one month of culture.The phenylurea-type cytokinin, 4-PU, was effective for plantlet regeneration from the mesophyll protoplasts ofB. platyphylla var.japonica. This suggests that there is potential for the use of 4-PU in the culture of protoplasts in many forest tree species.Abbreviations BAP 6-benzylaminopurine - 2,4-D 2,4-dichlorophenoxyacetic acid - FDA fluorescein diacetate - IBA indole-3-butyric acid - 2ip N ⁶-(2-isopentenyl)-adenine - NAA 1-naphthaleneacetic acid - 4-PU N-(2-chloro-4-pyridyl)-N–phenylurea - TDZ thidiazuron     

Dermatophytes isolated from patients in University Hospital,Kuala Lumpur,Malaysia

A total of 576 dermatophytes were isolated from patients with a variety of skin infections from January 1993 to May 2000. Ten species of dermatophytes were identified: Epidermophyton floccosum (0.7%), Microsporum audouinii (1.1%), M. canis (3.1%), M. gypseum (0.3%), Trichophyton concentricum(3.5%), T. equinum (0.2%), T. mentagrophytes (36.%), T . rubrum (53.8%), T. verrucosum (0.2) and T. violaceum (1.0%). The body sites most frequently affected by dermatophytes were the buttocks, nails and trunk. Anthropophilic dermatophytes made up 60.1% of the isolates; the most common species was T. rubrum, T. mentagrophytes and M. canis were the two main zoophilic dermatophytes. T. mentagrophytes was isolated from all body sites except the scalp. M. canis was found to be associated with domestic dogs and wasnot isolated from ethnic Malays. The only geophilic dermatophyte was M. gypseum, an uncommon dermatophyte associated with tinea pedis.This revised version was published online in October 2005 with corrections to the Cover Date.     

Tapesia yallundae collected from wheat stubble in South Africa

Tapesia yallundae var.yallundae is newly recorded from wheat stubble collected near Moorresburg in the western Cape Province of South Africa. Apothecia were observed on wheat stubble incubated for 8 months at 10°C under near-ultraviolet light. Single ascospore isolates produced colonies typical of the Wheat (W)-type in culture. Apothecia were also induced after single-conidial isolates were mated on wheat stubble and incubated at 10–15°C for 6 months. All single-conidial isolates were of the W-pathotype (Ramulispora herpotrichoides var.herpotrichoides).