Molecular analysis and pathogenicity of the Cladophialophora carrionii complex, with the description of a novel species.

Cladophialophora carrionii is one of the four major etiologic agents of human chromoblastomycosis in semi-arid climates. This species was studied using sequence data of the internal transcribed spacer region of rDNA, the partial beta-tubulin gene and an intron in the translation elongation factor 1-alpha gene, in addition to morphology. With all genes a clear bipartition was observed, which corresponded with minute differences in conidiophore morphology. A new species, C. yegresii, was introduced, which appeared to be, in contrast to C. carrionii, associated with living cactus plants. All strains from humans, and a few isolates from dead cactus debris, belonged to C. carrionii, for which a lectotype was designated. Artificial inoculation of cactus plants grown from seeds in the greenhouse showed that both fungi are able to persist in cactus tissue. When reaching the spines they produce cells that morphologically resemble the muriform cells known as the "invasive form" in chromoblastomycosis. The tested clinical strain of C. carrionii proved to be more virulent in cactus than the environmental strain of C. yegresii that originated from the same species of cactus, Stenocereus griseus. The muriform cell expressed in cactus spines can be regarded as the extremotolerant survival phase, and is likely to play an essential role in the natural life cycle of these organisms.

Saccharomyces cerevisiae en la fabricación del licor cocuy / Sacchromyces cerevisiae in the manufacturing of cocoy liquor

El licor "cocuy" es una bebida artesanal, producida por las comunidades rurales en el Occidente de Venezuela mediante un proceso de fermentación y destilación del mosto extraído del Agave cocui. Este estudio fue enmarcado en el "Programa Agave" con el propósito de contribuir a rescatar esta actividad productiva tradicional. En vista de la falta de información en relación al proceso autóctono se hicieron estudios de las levaduras fermentadoras, la optimización de la producción de etanol y la utilización del residuo de la destilización (vinaza) como medio de cultivo. Los aislados con mayor capacidad fermentativa fueron seleccionados e identificados mediante parámetros morfológicos y metabólicos. Se compararon los niveles de consumo de azúcar de las levaduras con mayor capacidad fermentativa. Se estudió el efecto de la adición del azúcar blanca comercial y/o del fosfato de amonio y en la producción del alcohol en el proceso artesanal. Las concentraciones de azúcares en el mosto se evaluaron por refractometría, y el contenido de alcohol de licor por hidrometría. La utilización de la vinaza para la producción de biomasa como un componente del medio de cultivo fue comparada con un medio sintético mediante medidas del peso seco de la biomasa. Se confirma el papel de sccharomyces ceravisiae en el proceso fermentativo espontáneo. Los resultados in situ evidenciaron un efecto favorable de la elevación del contenido de azúcar (11 a 18 °Brix) y de la adición de fosfato de amonio dibásico (0,2 g/l). En estas condiciones, el tiempo de fermentación del mosto se acortó y la producción de licor aumentó hasta un 92 por ciento. Se demostró la posibilidad de utilizar la vinaza como un componente para un medio de cultivo de esta levadura, para iniciar la fermentación y para la producción de biomasa como fuente de nutrientes de alto valor nutritivo para aves de corral o caprinos. Se recomienda apoyar los esfuerzos para desarrollar de esta importante fuente para los campesinos que habitan las zonas semiáridas de los estados Falcón y Lara

Black fungi: clinical and pathogenic approaches.

Data are presented on the clinically relevant black yeasts and their relatives, i.e., members of the Ascomycete order Chaetothyriales. In order to understand the pathology of these fungi it is essential to know their natural ecological niche. From a relatively low degree of molecular variability of the black yeast Exophiala dermatitidis, potential agent of brain infections in patients from East Asia, it is concluded that this species is an emerging pathogen, currently going through a process of active speciation. It is found to be an oligotrophic fungus in hot, moist environments, such as steambaths. Cladophialophora-, Fonsecaea- and Ramichloridium-like strains, known in humans as agents of chromoblastomycosis, are frequently found on rotten plant material, but the fungal molecular diversity in the environment is much higher than that on the human patient, so that it is difficult to trace the etiological agents of the disease with precision. This approach has been successful with Cladophialophora carrionii, of which cells resembling muriform cells, the tissue form of chromoblastomycosis, were found to occur in drying spines of cacti. Phagocytosis assays provide a method to distinguish between pathogens and non-pathogens, as the killing rates of strict saprobes proved to be consistently higher than of those species frequently known as agents of disease. The therapeutic possibilities for patients with chromoblastomycosis are reviewed.

[Chromomycosis by Rhinocladiella aquaspera: The first case in Venezuela.]. / Cromomicosis por Rhinocladiella aquaspersa: descripción del primer caso en Venezuela.

A case of chromomycosis induced by Rhinocladiella aquaspersa is decribed in Falcon State, which is considered as the first case in Venezuela, and the fifth one in the whole world of this species of Rhinocladiella. The case was observed in a five year-old child from the south part of Falcon State. The child presented wounds of two years of duration, in his upper left limb. These wounds were characterized by queloide cicatrices, and contiguous nodules, with a scalyo-scab surface. The disease was diagnosed through direct observation of cells extracted from the wounds and cleared with potassium hydroxide at 10%. The identification of R. aquaspersa was made by 1) The isolation in culture, using Lactritmel, Sabouraud-agar and Sablac as culture media; and 2) By observation, in slide culture, of dissemination structures characterized by erect conidiophores which were either simple or branched. The thermo-tolerance test applied indicate an optimum development temperature of 28 degrees C. It was not possible to reproduce the illness in Balb/c mice. The patient showed an unsatisfactory response to Itraconazol medication and improvement to an external local application therapy. Up to the present time, 370 cases of chromomycosis have been studied in Falcon State, with 21 cases in children. The suggests the existence of a susceptibility to this kind of mycosis from childhood.

[Mycetoma: report of 3 cases in Falcón State, Venezuela]. / Micetoma: reporte de tres casos en el Estado Falcón, Venezuela.

This is a report of three cases of mycetome studied in our laboratory during the last four years. We also informed about the evolution of the first case produced by Pyrenochaeta romeroi nova species reported by Borelli in 1959. All the patients were farmer men, 18, 42 and 54 years old, from the semiarid and subhumid zones of Falcon State, located on the northwest region of Venezuela. Clinically, all patients presented the mycetome syndrome (subcutaneous edema, sinus tract and "granules"), with a evolution of six months to three years. The lesions were localized in the inferior limbs in two of the patients and in the thorax in one of them. The clinical diagnose was confirmed by microbiological and mycological studies, isolating Nocardia brasiliensis in two cases and Madurella grisea in one. Two patients treated with Sulfas showed remission of the disease in a two years follow up. Including this report, 15 cases of mycetome have been reported in the Falcon State (Venezuela) in a period of thirty five years, representing only 9, 14% of the national casuistic. Actinomadura madurae and N. brasiliensis have been the most frequently isolated agents in this region. In order to determine the real endemicity of the mycetome in Venezuela, multidisciplinary clinical, inmunological, microbiological and epidemiological studies are recommended. According to the reported casuistic (15 cases), the mycetome should be a low frequency disease in Falcon State, Venezuela. We confirm that early diagnosis favors an efficient therapy.

[Effect of temperature and humidity on the frequency of pityriasis versicolor. Epidemiological study in the state of Falcón, Venezuela]. / Influencia de la temperatura y la humedad en la frecuencia de pitiriasis versicolor. Estudio epidemiológico en el Estado Falcón, Venezuela.

The survey covers 1546 people from three towns of Falcón, which present different climatological characteristics. The diagnostic of P.V. was confirmed through microscopic observation. It is demonstrated a notable increase of the frequency of P.V. during and after the puberty. Significative differences were found between the frequencies of P.V. in the semiarid zone (9%) and the sub-humid zone (12%). The lowest frequency (4%) corresponds to the temperate climate of La Sierra de Falcón. The study shows, for the first time, that a hot and humid climate favors the parasitism by Malassezia sp.