Cladosporium carrionii and Hormoconis resinae (C. resinae): cell wall and melanin studies.

Two phaeoid strains of the fungus Cladosporium carrionii (SR3 from a xerophyte species and PP8201 from a patient), and one strain of Hormoconis resinae (Cladosporium resinae), isolated from oil-impregnated soil, were analyzed for their cell wall composition by colorimetric methods, X-ray diffraction, infrared spectroscopy, and solid-state 13C-nuclear magnetic resonance. Results suggested that the cell walls were composed mainly of hexoses (34%-47%) as beta-1,3-glucan (some galactose and mannose were also present) and melanin, chitin being absent. Electron microscopic observations suggested that melanin was found not only in the cell wall but also in intracellular bodies resembling melanosomes.

[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.