A rapid DNA extraction protocol for a PCR-based detection of Histoplasma capsulatum in bat guano

A 36-year-old male was hospitalised with histoplasmosis after he had visited a bat cave as part of a tourist tour to the Costa Rican rainforests. With the PCR-method described here, the bat guano in the cave was identified as infection source. Thereupon, the cave was closed to tourists to avoid future infections with Histoplasma capsulatum, an anamorphic ascomycete (teleomorph: Ajellomyces capsulatus). A PCR-based assay was developed, to permit a fast, animal-experiment independent identification of environmental infection sources. Different DNA-extraction protocols were tested with bat guano from the cave in Costa Rica. A DNA extraction protocol based on mechanical rupture of the samples, CTAB, skim milk, chloroform and a subsequent purification with PVPP-spin-columns in combination with nested PCR was successfully used to detect the pathogenic fungus in bat guano.