Showing papers in "Revista Iberoamericana De Micologia in 2002"

Medical importance of biofilms in Candida infections.

Abstract: Many Candida infections involve biofilm formation on implanted devices such as an indwelling catheter, a prosthetic heart valve or a denture. Candida biofilms can be formed in vitro using several model systems. In the simplest of these, organisms are grown on the surfaces of small discs of catheter material or denture acrylic. Biofilms of C. albicans prepared in this way consist of matrix-enclosed microcolonies containing yeasts, hyphae and pseudohyphae, arranged in a bilayer structure. Candida biofilms are resistant to a range of antifungal agents in current clinical use, including amphotericin B and fluconazole. Current research suggests that multiple mechanisms are involved in biofilm drug resistance.

Fungal egg-parasites of plant-parasitic nematodes from Spanish soils.

Abstract: We have investigated the presence of fungal egg-parasites in Spanish soils with plant endoparasitic nematodes. Nine out of 68 samples (13%) yielded fungal parasites. The most common (seven strains) was Pochonia chlamydosporia var. chlamydosporia (= Verticillium chlamydosporium var. chlamydosporium), but Lecanicillium lecanii (= Verticillium lecanii) and Paecilomyces lilacinus were also found. Most strains were from cyst nematodes (Heterodera avenae or Heterodera schachtii). Biological factors related with the development and performance of these fungi as biocontrol agents were assessed in laboratory tetsts. Germination for most strains was around 90-100%. Higher biomass values were obtained, for most fungal strains, with complete or yeast extract peptone-glucose liquid media. P. lilacinus and L. lecanii showed the highest sporulation rates (1.0 x 10(9); and 1.5 x 10(10); conidia/g mycelium). All strains had optimum growth at 25 degrees C. High temperature (40 degrees C) was lethal to all fungi but low temperature (5 degrees C) allowed growth of L. lecanii. Most strains showed best growth close to pH 7. Several P. chlamydosporia strains produced diffusible pigments close to pH 3. Lack of moisture (aw = 0.887) in growth medium reduced but never arrested fungus growth. Proteolytic activity was, for all strains, the earliest and highest enzymatic activity. Amylolytic and pectinolytic activities showed the lowest values and the latter was undetectable for most strains. Pathogenicity (70-100percnt; egg infection) and severity (35-40 penetrating hyphae/egg) on Meloidogyne javanica were high for most strains tested. Our results show that agricultural soils in Spain contain fungal parasites susceptible to be biocontrol agents for plant-parasitic nematodes.

Screening for ligninolytic enzymes in autochthonous fungal strains from Argentina isolated from different substrata.

Abstract: The production of different extracellular ligninolytic enzymes was studied in autochthonous fungal strains from Argentina isolated from litter derived from hydrocarbon-polluted sites and from basidiocarps frowing on wood in forests. The strains tested were cultivated in a carbon-limited medium with shaking. Laccase activity reached higher levels than aryl-alcohol oxidase and manganese-dependent peroxidase activities in liquid cultures from different fungi. No lignin peroxidase activity was found in any strain assayed. Some species are reported for the first time as producers of different ligninolytic enzymes.

Dermatophytoses in Mexico

Abstract: The dermatophytic infections are superficial mycoses common in Mexico, they have an estimated frequency of 5% in dermatological outpatients. In this review we present a global view of these mycoses as well as their etiological agents in tinea capitis, tinea pedis, tinea corporis, tinea cruris and onychomycosis and also uncommon infections such as tinea imbricata and epidermophytosis of the diaper area. We also analyze these infections in diabetic patients, healthy carriers and dermatophytic infections in pets and laboratory animals. The most important publications about dermatophytosis in Mexico in the dermatological, epidemiological or mycological area are reviewed, specially those published in the last ten years.

Efecto de extractos alcohÓlicos de plantas silvestres sobre la inhibiciÓn de crecimiento de Aspergillus flavus, Aspergillus niger, Penicillium chrysogenum, Penicillium expansum, Fusarium moniliforme y Fusarium poae

Abstract: Fungicidal activity of wild plants Larrea tridentata, Karwinskia humboldtiana, Ricinus communis, Eucalyptus globulus, Ambrosia ambrosioides, Nicotiana glauca, Ambrosia confertiflora, Datura discolor, Baccharis glutinosa, Proboscidea parviflora, Solanum rostratum, Jatropha cinerea, Salpianthus macrodonthus y Sarcostemma cynanchoides was evaluated against the moulds species Aspergillus flavus, Aspergillus niger, Penicillium chrysogenum, Penicillium expansum, Fusarium poae y Fusarium moniliforme moulds species. Alcoholic extracts 6% (w/v) were prepared using six grams of dried plant powders (leaves and stems) and alcohol (70% ethanol or 70% methanol). A spore suspension (1x10 6 ufc/ml) of each mould was prepared by adding saline solution (0.85%) and 0.1% tween 80. The Extracts were mixed with Czapeck yeast agar (CYA) at 45-50 °C in 1:10 relation on Petri dishes. Triplicate Petri dishes of each treatment and for each mould were centrally inoculated and three Petri dishes were used without treatment as controls. The inoculated dishes and controls were incubated at 25 ′ 2 °C for eight days. The incubated dishes were examinated each 48 h and after the colony diameter (radial growth) was measured. Two mould species were controlled by L. tridentata, B. glutinosa and P. parviflora. Extracts of L. tridentata in methanol or ethanol at 41.5-100% inhibited all six species of moulds.

Clinical and epidemiological survey of dermatophytoses in Jaen (Spain)

Abstract: Prevalence of dermatophytosis, with respect to age and sex and dermatophyte species, in Jaen was investigated during a period of three years (1996-1999). The prevalence of dermatophytosis over three years was 4.48 cases / 1000 inhabitants. The isolated species were: Microsporum canis (48.6%), Trichophyton mentagrophytes (27.1%), Epidermophyton floccosum (10%), Trichophyton rubrum (8.6%), Trichophyton violaceum (4.3%), and Microsporum gypseum (1.4%). The most frequently observed dermatophytoses were tinea corporis (62.8%), followed by tinea capitis (12.8%); other clinical forms encountered were, in decreasing order of frequency, tinea cruris, tinea pedis and tinea unguium, tinea faciei and tinea barbae. Men were more affected than women.

Antagonistic activity of Penicillium oxalicum Corrie and Thom, Penicillium decumbens Thom and Trichoderma harzianum Rifai isolates against fungi, bacteria and insects in vitro.

Abstract: The antibiotic activity of 70 isolates belonging to the genera Aspergillus, Penicillium, Fusarium, Alternaria and Trichoderma was tested as preliminary screening. The highest activity was obtained with three Penicillium oxalicum isolates, one Penicillium decumbens isolate and the Trichoderma harzianum isolate. After that, we chose these five isolates in order to carry out other studies with bacteria, fungi and insects. Extracts from these isolates were obtained. The extracts were tested for antibiotic activity with positive results, which implies that metabolite production is involved in this antagonistic effect. The highest activity was shown by T. harzianum and P. oxalicum extracts, but there was high variability among P. oxalicum isolates.

[Epidemiology of candidemia in Spain - Multicenter study]

Abstract: The results of the epidemiological study on candidemias with the highest number of cases carried out in Spain is presented. This study is included in the Epidemiological Survey of Candidemia in Europe supported by the ECMM in which another five countries take part. In the Spanish study, 19 hospitals participated, 290 candidemia episodes were analysed (80 in children under 15 years and 210 in adults), 293 strains of yeasts being isolated. Both in children and in adults, the risks factors more frequently observed were the intravenous catheter and previous antibiotic therapy. In adults, the most habitual underlying disease was the solid tumor and, in children, hematological diseases. Candida albicans was the most prevalent species isolated in adults (46.1%) and Candida parapsilosis in children (50%). As part of the therapy, the intravenous line was removed and antifungal treatment was prescribed to 74% and 92.5% of children, respectively and to 43.8% and 73.8% of adults. The antifungal agent of election in adults was fluconazole (54.8%) and liposomal amphotericin B (58.1%) in children. The global mortality of the study was 38.9%, which for ages was major in adults (41.4%) than in children (38.7%). The geographical distribution of the isolated species was homogeneous, C. albicans being the predominant species, with the exception of Galicia and Extremadura where C. parapsilosis was the most frequent.

Microbiological diagnosis of mycoses

Abstract: ©2002 Revista Iberoamericana de Micologia Apdo. 699, E-48080 Bilbao (Spain) 1130-1406/01/10.00 Euros El diagnostico microbiologico es un paso esencial en el establecimiento de la etiologia de las enfermedades infecciosas y aunque su caracteristica fundamental es la identificacion del agente etiologico, en la actualidad incluye tambien la determinacion de la sensibilidad in vitro a los antimicrobianos y la utilizacion de metodos de tipado que permitan la diferenciacion intraespecifica de los aislamientos. Siempre que sea posible, la identificacion de los aislamientos fungicos debe de realizarse a nivel de especie, ya que esta informacion puede ser muy importante para orientar el tratamiento antifungico hasta que se dispongan de los resultados de sensibilidad in vitro. Un ejemplo de esta necesidad lo tenemos con el genero Scedosporium, donde Scedosporium apiospermun es sensible al miconazol, voriconazol, posaconazol y ravuconazol, mientras que Scedosporium prolificans, una especie muy relacionada, es resistente a la mayoria de los antifungicos [1,2]. En el diagnostico micologico se estan produciendo avances importantes que estan permitiendo un diagnostico mas rapido y eficiente. La velocidad en la obtencion de este diagnostico es un aspecto fundamental en la medicina actual, ya que un diagnostico rapido posibilitara la prescripcion de un tratamiento antifungico especifico que permitira un uso racional de los antifungicos y limitara el desarrollo de resistencias. Aunque todavia no existe un consenso sobre el tema, el tiempo ideal para que el clinico pueda utilizar los datos del diagnostico micologico para guiar el tratamiento antifungico varia segun el tipo de paciente. Asi, en pacientes ambulatorios los resultados diagnosticos se necesitan en tiempo real (menos de 10 min), ya que el paciente dejara la consulta con el tratamiento y no volvera a una nueva consulta hasta dias despues, mientras que en pacientes hospitalizados los resultados diagnosticos seran necesarios lo antes posible, aunque el establecimiento de una terapia empirica permitira disponer de mas tiempo para realizar el diagnostico. Diagnostico en tiempo real

[Effect of alcoholic extracts of wild plants on the inhibition of growth of Aspergillus flavus, Aspergillus niger, Penicillium chrysogenum, Penicillium expansum, Fusarium moniliforme and Fusarium poae moulds].

Abstract: Fungicidal activity of wild plants Larrea tridentata, Karwinskia humboldtiana, Ricinus communis, Eucalyptus globulus, Ambrosia ambrosioides, Nicotiana glauca, Ambrosia confertiflora, Datura discolor, Baccharis glutinosa, Proboscidea parviflora, Solanum rostratum, Jatropha cinerea, Salpianthus macrodonthus y Sarcostemma cynanchoides was evaluated against the moulds species Aspergillus flavus, Aspergillus niger, Penicillium chrysogenum, Penicillium expansum, Fusarium poae y Fusarium moniliforme moulds species. Alcoholic extracts 6% (w/v) were prepared using six grams of dried plant powders (leaves and stems) and alcohol (70% ethanol or 70% methanol). A spore suspension (1x10(6); ufc/ml) of each mould was prepared by adding saline solution (0.85%) and 0.1% tween 80. The extracts were mixed with Czapeck yeast agar (CYA) at 45-50 degrees C in 1:10 relation on Petri dishes. Triplicate Petri dishes of each treatment and for each mould were centrally inoculated and three Petri dishes were used without treatment as controls. The inoculated dishes and controls were incubated at 25 +/- 2 degrees C for eight days. The incubated dishes were examined each 48 h and after the colony diameter (radial growth) was measured. Two mould species were controlled by L. tridentata, B. glutinosa and P. parviflora. Extracts of L. tridentata in methanol or ethanol at 41.5-100% inhibited all six species of moulds.

The presence of fluconazole-resistant Candida dubliniensis strains among Candida albicans isolates from immunocompromised or otherwise debilitated HIV-negative Turkish patients.

Abstract: The newly described species Candida dubliniensis phenotypically resembles Candida albicans in many respects and so it could be easily misidentified. The present study aimed at determining the frequency at which this new Candida species was not recognized in the authors’ university hospital clinical laboratory and to assess antifungal susceptibility. In this study six identification methods based on significant phenotypic characteristics each proposed as reliable tests applicable in mycology laboratories for the differentiation of the two species were performed together to assess the clinical strains that were initially identified as C. albicans. Only the isolates which have had the parallel results in all methods were assessed as C. dubliniensis. One hundred and twentynine C. albicans strains isolated from deep mycosis suspected patients were further examined. Three of 129 C. albicans ( two from oral cavity, one from sputum) were reidentified as C. dubliniensis. One of the strains isolated from oral cavity and that from sputum were obtained at two months intervals from the same patient with acute myeloid leukemia, while the other oral cavity strain was obtained from a patient who had previously been irradiated for a laryngeal malignancy. Isolates were all susceptible in vitro to amphotericin B, with the MIC range 0.125 to 0.5 µg/ml, resistant to fluconazole, with the MICs ≥ 64 µg/ml, and resistant to ketoconazole, with the MICs ≥ 16 µg/ml, dose-dependent to itraconazole with the MIC range 0.25-0.5 µg/ml, and susceptible to flucytosine, with the MIC range 1-4 µg/ml.

Mycoses at dawn of XXI Century

Abstract: Uno de los mejores indicadores de la importancia que están adquiriendo las micosis, principalmente las infecciones invasoras, es la continua e imparable notifica-ción de su incremento clínico [1-3]. Debemos destacar que este aumento ha ido parejo, por una parte, a la mejora de los conocimientos, técnicas y tratamiento médicos y quirúrgicos que han prolongado la calidad y esperanza de vida de los seres humanos en los países de mayor capaci-dad económica y, por otra, a la aparición de infecciones y enfermedades que alteran al sistema inmune, como el sida [4,5]. Aunque se describen con creciente frecuencia infecciones producidas por los más diversos organismos fúngicos [6], la mayoría de las infecciones siguen siendo producidas por dermatofitos, Malassezia, Candida, Aspergillus y Cryptococcus [7-9]. Estos tres últimos agen-tes están asociados a infecciones invasoras con un pronós-tico más sombrío, en parte debido a las enfermedades subyacentes que predisponen a estas micosis y, en parte, a la mortalidad directa asociada a la acción patógena de estos microorganismos. Las candidiasis invasoras están relacionadas princi-palmente con enfermos quirúrgicos, pacientes ingresados en unidades de cuidados intensivos, personas infectadas por el virus de la inmunodeficiencia humana (VIH) o cualquier enfermo con una inmunosupresión importante, adhesión a plásticos biomédicos (como catéteres); sin embargo, esta especie puede aislarse de un alto porcentaje de muestras orales de lactantes sanos que no padecen can-didiasis oral y aunque su origen puede ser exógeno (teti-nas y chupetes contaminados), esta especie forma parte de la microbiota oral y, tal vez, digestiva, durante periodos prolongados [10]. Uno de los problemas planteados en la etiología de las candidiasis es el posible aumento de las infecciones producidas por especies diferentes a C. albi-cans que en principio deben considerarse como menos sensibles al fluconazol, uno de los antifúngicos más empleados. La aspergilosis puede presentarse de múltiples for-mas clínicas, principalmente asociadas al aparato respira-torio y a la piel, tanto en personas inmunocompetentes (aspergiloma), atópicas (aspergilosis broncopulmonar alérgica) o inmunosuprimidas (aspergilosis pulmonar invasora). Las aspergilosis invasoras se observan princi-palmente en personas con una neutropenia o una inmuno-supresión severa, principalmente en receptores de trasplantes de órganos, con una mortalidad asociada ele-vada, tanto por los problemas que plantea el diagnóstico precoz como por el difícil tratamiento antifúngico especí-fico que plantea [9]. La mayoría de estas aspergilosis están producidas por Aspergillus fumigatus pero otras especies también han sido aisladas en diferentes pacientes con aspergilosis, como Aspergillus niger, Aspergillus terreus o Aspergillus flavus (Figura 1). Las …

Comparative study of two culture media for the detection of phospholipase activity of Candida albicans and Cryptococcus neoformans strains

Abstract: Phospholipase activity (PHA) is considered a virulence factor related to pathogenicity of Candida albicans and Cryptococcus neoformans. The aim of this work was to compare the ability of two culture media: malt egg-yolk agar (MEA) and Sabouraud-egg yolk agar (SEA), for the detection of phospholipase activity. Forty four strains of C. neoformans and 54 of C. albicans isolated from different clinical specimens of human origin were studied. The phospholipase production was determined as a ratio between the diameter of each colony and the corresponding lysis halo. The values ranged between 0 and 1, and the highest level of enzymatic activity was the nearest to 0. Enzymatic activity was observed in 34 C. neoformans strains, grown either in MEA or SEA media; 59 % of enzyme producers were detected in SEA only, while five strains (15 % of producers) were detected just in MEA medium. Phospholipase activity was observed in both media only in nine of 34 enzyme producer strains. Forty two out of 54 strains of C. albicans were detected as enzyme producers; 31 of them (73.8 %) were detected in MEA medium only. On the other hand 10 strains (23.8 % of the enzyme producers) showed phospholipase activity just in SEA medium. Detection of PHA could be done by both media in one case only. In order to evaluate the time needed to detect PHA, 41 C. albicans strains were incubated 72 h. They were read at 24 h intervals. No enzyme activity was detected at 24 h, 15 enzyme producer strains remain negative at 48 h and the halos of all strains with PHA were better distinguished after 72 h. It was possible to conclude that neither MEA nor SEA media were good enough as the unique medium to detect phospholipase activity. Nevertheless, MEA was better than SEA to detect PHA of C. albicans after 72 h incubation. The opposite situation was seen when we studied PHA in C. neoformans strains. In this case, greater sensibility was observed with SEA medium compared with MEA medium. Six days incubation, but not longer incubation times, were necessary to detect phospholipase activity in C. neoformans strains.

Zygomycosis: A report of eleven cases and a review of the Brazilian literature.

Abstract: Eleven cases of zygomycosis (mucormycosis) observed throughout an eighteen year period (1982-2000) have been reviewed. The most important demographic and clinical data of seven patients were tabulated. The remaining four are related as illustrative cases. Seven patients presented with the pulmonary form of the disease; two patients presented with the pulmonary manifestation associated with sinusitis; and two patients presented with the rhinocerebral form. Predisposing conditions, in decreasing order of frequency, were diabetes mellitus (6), renal transplantation (2), associated with pancreas-kidney transplantation and diabetes (1), bone marrow aplasia (1), and chronic obstructive lung disease treated with corticosteroids (1). The diagnoses were based on the detection of characteristic zygomycetous hyphae in tissue. The causative organim was isolated and identified in only four cases; three were due to Rhizopus arrhizus, and one to Absidia corymbifera. In addition the Brazilian literature on zygomycosis is reviewed.

Current treatment of dermatophytosis

Abstract: The aim of this review article is to discuss topical and systemic antifungal treatment of dermatophyte infections with current antifungal drugs.

Estudio multicéntrico sobre la epidemiología de las candidemias en España

Abstract: The results of the epidemiological study on candidemias with the highest number of cases carried out in Spain is presented. This study is included in the Epidemiological Survey of Candidemia in Europe supported by the ECMM in which another five countries take part. In the Spanish study, 19 hospitals participated, 290 candidemia episodes were analysed (80 in children <15 years and 210 in adults), 293 strains of yeasts being isolated. Both in children and in adults, the risk factors more frequently observed were the intravenous catheter and previous antibiotic therapy. In adults, the most habitual underlying disease was the solid tumor and, in children, hematological diseases. Candida albicans was the most prevalent species isolated in adults (46.1%) and Candida parapsilosis in children (50%). As part of the therapy, the intravenous line was removed and antifungal treatment was prescribed to 74 % and 92.5 % of children, respectively and to 43.8 % and 73.8 % of adults. The antifungal agent of election in adults was fluconazole (54.8 %) and liposomal amphotericin B (58.1 %) in children. The global mortality of the study was 38.9 %, which for ages was major in adults (41.4 %) than in children (38.7 %). The geographical distribution of the isolated species was homogeneous, C. albicans being the predominant species, with the exception of Galicia and Extremadura where C. parapsilosis was the most frequent.

New strategies for treatment of Candida vaginal infections.

Abstract: New strategies for treatment of vaginal candidiasis have been recently exploited, due to widespread occurrence of this disease, in particular as recurrent infections, limitations of safe and efficacious antifungals as well as the lack of reliable preventative approaches. In this review new chemotherapeutic and immunotherapeutic strategies, based on the improved understanding of the immunopathogenesis of this prevalent human infection, will be discussed. The role of killer antibodies (or their molecular derivatives), i.e. antibodies that show antibiotic activity bearing the internal image of a yeast killer toxin (KT), characterized by a wide spectrum of microbicidal activity, and of the specific cell wall KT receptor as putative new therapeutic agents and preventative or therapeutic vaccines, respectively, will be particularly outlined.

Proteinase detection, DNA typing and antimycotic susceptibility of Candida isolates from Colombian women with vulvovaginal candidiasis

Abstract: Forty non-pregnant Colombian women (ages 18 - 45) with vulvovaginal candidiasis diagnosis (VVC) were enrolled in a blinded study to compare the efficacy of Itraconazole (ITRA) 400 mg vs. Fluconazole (FLU) 150 mg. Sexual partners received similar therapy. Proteinase detection by the Staib method and minimal inhibitory concentration (MIC) for FLU and ITRA by Etest method were performed in all Candida isolates. Patients were followed one year to determine clinical evolution and recurrence of VVC (RVVC). The strain identity of the RVVC isolates was determined by contour-clamped homogeneous electric field (CHEF) gel electrophoresis karyotyping and restriction fragment length polymorphism (RFLP). Thirty patients (75%) had one or two episodes of VVC/year, 83% of these were due to Candida albicans, while ten patients (25%) developed RVVC (three or more episodes/year); seven of them were treated with FLU. Non-C. albicans Candida species were detected in five of 30 (17%) of the patients with VVC and in seven of ten (70%) patients with RVVC (p=0.003). Isolates from nineteen patients were proteinase positive. Proteinase production and type of treatment were not related to recurrence of VVC (p>0.05). DNA typing revealed that in this population RVVC might be due to the same strain, substrain shuffling or different strains and species.

Human infections by black yeasts of genus Exophiala

Abstract: Clinical and laboratory aspects of the infections caused by Exophiala species are reviewed with regard to its epidemiology, diagnosis and treatment. Exophiala is a genus of dematiaceous hyphomycetes whose taxonomy and nomenclature undergo constant revision. Exophiala species are widely distributed in nature, and they are uncommon human pathogens. In recent years it appears to have increased its frequency as a cause of human infections, mainly in immunocompromised patients. They have been associated with phaeohyphomycosis, chromoblastomycosis, eumycotic mycetoma and disseminated infection. The procedures recommended for diagnosis consist of detection of fungal elements in tissue and growth of the organism in culture. Identification is mostly based upon microscopic observation of morphological characteristics and conidiogenesis, combined with the evaluation of physiological tests and nitrate and carbohydrate assimilations. Antifungal agents such as amphotericin B, itraconazole and voriconazole showed in vitro activity to most of the Exophiala species of clinical interest. The therapeutic recommendations are mainly deduced from the observation of single cases.

Identification of Candida albicans by polymerase chain reaction amplification of CaYST1 gene intron fragment.

Abstract: A single pair of primers, deduced from the intron nucleotide sequence of the Candida albicans CaYST1 gene, was used in PCR analysis performed with both genomic DNA and whole cells of clinical isolates of Candida species and other microorganisms. All the clinical C. albicans isolates generated the expected 310 bp amplicon; other Candida species as well as laboratory strains belonging to other fungal genera failed to amplify any DNA fragment, except for Candida pseudotropicalis (amplicon of 1200 bp), Kluyveromices marxianus (amplicon of 1250 bp) and Cryptococcus neoformans (several amplicons longer than 1200 bp). Unusual C. albicans isolates from Africa also yielded the expected 310 bp amplicon. These results indicate that genes containing intron sequences may be useful to design species-specific primers for identification of fungal strains by PCR. The sensitivity of the method was evaluated for C. albicans genomic DNA by using both various DNA concentrations (224 ng to 2.7 pg) and different cell amounts (10(7); to 5 cells). The results obtained may be useful in earlier detection of candidiasis.

Presence of Pleurotus ostreatus in Patagonia, Argentina

Abstract: Specimens belonging to the genus Pleurotus were collected growing on fallentrunks of Araucaria araucana, a native tree with a poorly known mycoflora, whichgrows in Patagonia, Argentina. Fruitbodies were produced in culture on sawdustfrom an isolated strain. Interspecific pairing tests performed between matingtypes of Pleurotus from Patagonia and tester strains of P. pulmonarius and P.ostreatus showed the Patagonia strain to be 100 % compatible with P. ostreatusand incompatible with P. pulmonarius. Dikaryons obtained on sawdust were ferti-le, since they were able to produce fruitbodies and viable spores. This is the firstdocumented record of P. ostreatus from Argentina and the first gilled fungusfound growing on Araucaria araucana.Pleurotus ostreatus, Araucaria araucana, Mating tests, Patagonia

Characterization of Paracoccidioides brasiliensis atypical isolates by random amplified polymorphic DNA analysis.

Abstract: Two atypical Paracoccidioides brasiliensis strains (yeast form at room temperature) have been isolated from chronically infected patients living in Brazil. Different random primers were used to characterize these isolates and compare them to typical strains. The RAPD patterns allowed the differentiation of all the selected isolates. Their genetic distance ranged from 5% to 80% of non-shared bands depending on the strains and the primer used. The RAPD data were used to build a Wagner phenogram, which showed two major branched with more than 56% of genetic distance separating them. No significant difference was observed between the atypical isolates and the others suggesting that specific genes are involved in the dimorphism phenomenon.

Should antifungal treatments be based upon results of antifungal susceptibility testing

Abstract: The development of reliable procedures for detecting resistance in vitro to antifungal agents and the increase in the prevalence of mycoses due to organisms with intrinsic or secondary resistance have reinforced the clinical relevance of antifungal susceptibility testing. A matter is currently in the limelight: can antifungal agents indications be based on susceptibility testing results? The present paper reviews the reliability of susceptibility testing procedures available at the moment, their capability for predicting therapeutic failure, and their clinical usefulness.

[Study of dermatophytoses in Lanzarote (1995-199)].

Abstract: We report on the incidence of dermatophytes isolated in Lanzarote island from June-95 to December-99. We gathered 76 samples. Tinea corporis was the most frequent (40.79%) condition, and after this, tinea pedis (26.31%). Trichophyton rubrum was the commonest agent isolated involving 52.63% of patients. We compare our results with other canarian studies, and with clinical patterns described in other spanish studies published in the 1990's. From these comparations we can deduce: a) The distribution of clinical pictures is not homogeneous among the papers, b) tinea corporis etiology is heterogeneous among the series and c) tinea pedis etiology is homogeneous in most of studies. We believe that the comparison by clinical forms avoids any bias due to distribution of clinical forms.

Three years incidence of dermatophytes in a hospital in Porto (Portugal)

Abstract: We evaluated the incidence of dermatophytes isolated at our hospital in the years of 1997 to 2000 and correlated it with anatomical site and age. Trichophyton rubrum was the predominant species in all anatomical sites, excluding scalp, followed by Microsporum canis, the leading agent of tinea capitis. All dermatophytosis, except tinea capitis by M. canis and Trichophyton schoenleinnii appeared mainly in adult patients. Our results revealed no substantial differences to other portuguese studies regarding the major agents. We found a relatively high incidence of T. schoenleinnii as second tinea capitis agent.

Cryptococcus neoformans arthritis in a renal transplant recipient

Abstract: We present a Cryptococcus neoformans knee joint infection in a diabetic renal transplant patient treated with steroids, cyclosporin, and mycofenolate mofetil. We discuss reported cases of cryptococcal arthritis.

Role of natural killer T cells in host defence against cryptococcal infection.

Abstract: Cryptococcosis is an opportunistic fungal infectious disease that often occurs in severely immunocompromised patients. Host defence against the causative microorganism is largely mediated by cellular immunity, and Th1 cytokines, such as IFN-gamma, play central roles in the host protective responses. IL-12 and IL-18 activate the synthesis of IFN-gamma by innate immune cells, including NK, NKT and gamma delta T cells and promote the differentiation of Th1-type acquired immune responses. Recently, NKT cells, which are involved in the recognition of glycolipid antigens, have attracted much attention based on their potent immunomodulating activities. Several studies have reported the role of this particular component of innate immune responses in tumor immunity and pathogenesis of autoimmune diseases. In this review, I outline the recent findings on the role of NKT cells in host defence against infectious microorganisms, with a special focus on our data emphasizing the importance of this subset of immunocytes in the development of acquired as well as early host protection against cryptococcal infection.

[Salivary pH and culture determinations in HIV infected and non-HIV infected patients with oral candidosis].

Abstract: The aim of the present study was to determine the salivary pH in HIV (Human Immunodeficiency Virus) positive(+) and negative(-) patients and in a control group, for assessing if variations or changes in pH are related to the development of oral candidosis and the species isolated. The sample comprised 120 patients from the Infectology Unit of the Mexico General Hospital, and from the School of Dentistry, UNAM. Three study groups were performed: with oral candidosis HIV+, with oral candidosis HIV-, and a control group. All patients filled out a clinical data questionnaire and signed an informed consent document. A 2 ml sample of non-stimulated saliva was obtained from each patient. The pH was measured and the sample was cultured on dextrose Sabouraud agar. The Candida species determinations were performed by the API 20 C AUX system and statistically analyzed. In the HIV+ group, the pH mean was 6.17, with most prevalence of Candida albicans type I and pseudomembranous candidosis. In the HIV- group prosthesis users, the pH mean was 6.29, with most prevalence of C. albicans type I, but with erythematous candidosis. The control group showed a mean pH of 6.78. A statistically significant difference among pH values was found (F= 15.45 p<0.01). The present study revealed that in HIV+ patients, the most significant predisposing factors are: immunosuppression, antibiotic therapy, bad hygiene, anemia, leucoplakia, and diabetes. The salivary pH with acidic values (more in HIV+ patients) significantly favors candidosis development, specially for C. albicans and C. glabrata species and primarily the pseudomembranous and erythematous clinic types. The pH is not a determinant for Candida growth, but could affect the adherence and invasiveness of the yeast.

Three cases of imported histoplasmosis in our hospital

Abstract: Since 1999 we have observed three cases of imported histoplasmosis in our hospital. One was an immunocompetent individual and two further patients were immunosuppressed (renal transplantation and HIV infection C3). Two patients were born in endemic areas (Equatorial Guinea and Ecuador) and a third patient had a history of previous travel to the Peruvian Amazonia. The different clinical presentations and diagnostic tools of histoplasmosis are discussed.

Diminution of antifungal activity of fluconazole associated with ibuprofen and piroxicam in experimental histoplasmosis of hamsters (Mesocricetus auratus)

Abstract: The aim of this study was to determine if tha association of non-steroid antiinflammatory drugs (piroxicam and ibuprofen) with fluconazole, affects the antifungal activity of the azole compound, in an experimental model histoplasmosis in hamsters (Mesocricetus auratus). Sixty hamsters were intracardially inoculated with 4x10(6) yeasts of Histoplasma capsulatum var. capsulatum. Treatments began one week after the challenge and continued for three weeks. The hamsters were divided in six groups of ten animals each and received the following treatment: 1- fluconazole 8 mg/kg/day; 2- ibuprofen 20 mg/kg/day; 3- piroxicam 20 mg/kg/day; 4- fluconazole+ibuprofen; 5- fluconazole+piroxicam and 6- only received the solvent of these drugs. One week after ending the treatment, all the animals were sacrified and the evaluation of the treatments was based on the results of blood cultures, on the determination of colony forming units per gram of spleen, and the histopathologic studies of the same organ. The animals treated with fluconazole plus ibuprofen or piroxicam showed more colony colony forming units per gram (3.9x10(7) and 3.3x10(7)) when compared with the animals treated with fluconazole alone (0.9x10(7)). The histopathologic results of the hamsters that received fluconazole showed well-organized granulomas with few yeast-like elements inside the macrophages. In contrast, those which received fluconazole associated with antiinflammatory drugs presented lax granulomas containing numerous yeast-like elements. These findings let us to conclude that non-steroids antiinflammatory drugs diminish the antifungal efficacy of fluconazole in this animal model.