PANFUNGAL PCR ASSAY FOR DETECTION OF FUNGAL INFECTION IN HUMAN BLOOD SPECIMENS

A novel panfungal PCR assay which detects the small-subunit rRNA gene sequence of the two major fungal organism groups was used to test whol e-blood specimens obtained from a series of blood or bone marrow trans plant recipients. The 580-bp PCR product was identified after amplific ation by panfungal primers and hybridization to a 245-bp digoxigenin-l abeled probe. The lower limit of detection of the assay was approximat ely four organisms per milliliter of blood. Multiple whole-blood speci mens from five patients without fungal infection or colonization had n egative PCR results. Specimens from 11 infected patients had positive PCR results. Blood from three patients with pulmonary aspergillosis ha d positive PCR results: one patient's blood specimen obtained in the w eek prior to the diagnosis of infection by a positive bronchoalveolar lavage fluid culture result was positive by PCR, and blood specimens o btained from two patients 1 to 2 days after lung biopsy and which were sterile by culture were positive by PCR. The blood of four patients w ith candidemia, three patients with mixed fungal infections, and one p atient with fusariosis also had positive PCR signals. The panfungal PC R assay can detect multiple fungal genera and may be used as an adjunc t to conventional methods for the detection of fungal infection or for describing the natural history of fungal infection. Further studies a re needed to define the sensitivity and specificity of this assay for the diagnosis of fungal infection prior to the existence of other clin ical or laboratory indications of invasive fungal infection.