Sequences from the aspergillopepsin PEP gene of Aspergillus fumigatus: evidence on their use in selective PCR identification of Aspergillus species in infected clinical samples

In immunodeficient patients, Aspergillus species emerge as circumstantial p athogens. Aspergillus Fumigatus is a distant first among the pathogenic asp ergilli, which cause deep-seated mycoses. Sequences of the pep gene of A. f umigatus as potential PCR primers, which have not been tested before, were used to identify this species and if possible, differentiate it from other, co-identified, clinically important species of the genus, We present resul ts of the three most promising primer pairs, pep-1/pep-22, pep-15/pep-22 an d pep-21/pep32. The second pair was of better specificity when tested with DNA extracted from pure cultures of a multitude of aspergilli, whereas the first co-amplified four clinically significant Aspergillus species. The com patibility of the PCR method with the CTAB DNA extraction protocol varied a ccording to the biological fluid tested and the primer pair used. The first two pairs showed moderate adaptability to the different commercial DNA ext raction kits, which were tested in whole blood, spiked with Aspergillus fum igatus hyphae and conidia - as were all the biological fluids used. Restric tion of the amplification products with MspI produced distinct patterns for different Aspergillus spp. This approach, as a potential diagnostic tool, seems reliable and sensitive due to its flexibility, speed, low cost, ease of application and selectable breadth of detection. (C) 1999 Federation of European Microbiological Societies, Published by Elsevier Science B.V. All rights reserved.