Fungal PCR-assay for the detection of invasive aspergillosis

A universal PCR-assay for the detection of fungal DNA was compared with mic roscopy and culture for the diagnosis of invasive aspergillosis using 78 sa mples from 42 patients. Eighteen patients were suffering from invasive aspergillosis, 5 patients we re colonized with Aspergillus in the respirator) tract, 19 patients did not show any sign of aspergillosis. Samples from 6 of the 18 patients with inv asive aspergillosis were microscopically positive with true mycelia, 15 of 18 grew Aspergillus in culture, 16 of 18 were PCR-positive. The combination of microscopy and culture led to the diagnosis in 17 of 18 patients, the c ombination of microscopy and PCR in 16 of 18 and the combination of culture and FCR in all the 18 patients. For 3 of 18 patients, PCR was the diagnost ic key: in 2 biopsies the histologically detected fungal elements were iden tified as Aspergillus, in 3 bronchial lavages from 1 patient nothing but PC R was positive for Aspergillus. Four out of 5 culture positive patients wit h Aspergillus colonization were also PCR positive; one out of 19 patients w ithout aspergillosis was culture positive, 3 out of 19 were falsely PCR pos itiv: Candida colonization in the upper respiratory tract or Pneumocystis c arinii pneumonia did not lead to false positiv Aspergillus-PCR results. In conclusion, the evaluated fungal PCR-assay can supplement conventional m ethods for the diagnosis of invasive aspergillosis.