NOTE / NOTE Detection of Aspergillus in lung and other tissue samples using the MycAssay Aspergillus real-time PCR kit C. Lass-Flörl, S.A. Follett, A. Moody, and D.W. Denning Abstract: The MycAssay™ Aspergillus real-time PCR kit was tested on tissues from patients with invasive fungal infec- tions. Tissue samples from nine organ transplant recipients and 33 patients with haematological malignancy were from lung (n = 30), skin (n = 4), and others. Samples were preprocessed with proteinase K and lyticase, followed by DNA extraction and real-time PCR. For all samples, the sensitivity of the MycAssay Aspergillus test was 82% and specificity 79% relative to microscopy and 90% and 64%, respectively, compared with Aspergillus culture. The positive predictive value and negative predictive values compared with culture were 69% and 88% and were 88% and 69% compared with microscopy, respec- tively. The MycAssay Aspergillus test detected tissue invasive infections with Aspergillus fumigatus, Aspergillus flavus, and Aspergillus terreus. Key words: invasive fungal infection, PCR, Aspergillus terreus, Aspergillus flavus, Aspergillus fumigatus. Résumé : La trousse de PCR en temps réel MycAssay™ Aspergillus a été testée sur les tissus de patients souffrant d’infec- tions fongiques invasives. Les échantillons de tissus provenant de neuf patients transplantés et 33 patients souffrant d’un can- cer hématologique comprenaient le poumon (n = 30), la peau (n = 4), et d’autres tissus. Les échantillons ont été prétraités à la protéinase K et à la lyticase, puis l’ ADN a été extrait et soumis à la PCR en temps réel. Pour tous les échantillons, la sensi- bilité du MycAssay Aspergillus était de 82 % et la spécificité de 79 % relativement à la microscopie, et de 90 % et 64 % com- parativement à la culture d’Aspergillus. Les valeurs de prédiction positives et négatives comparativement à la culture, étaient de 69 % et 88 % alors qu’elles étaient de 88 % et 69 % comparativement à la microscopie, respectivement. Le MycAssay As- pergillus a détecté les infections invasives des tissus par Aspergillus fumigatus, Aspergillus flavus et Aspergillus terreus. Mots‐clés : infection fongique massive, PCR, Aspergillus terreus, Aspergillus flavus, Aspergillus fumigatus. [Traduit par la Rédaction] The first attempt to use molecular methods directly in hu- man specimens was described by Imhof et al. in 2003, who successfully used real-time PCR with a broad-range fungal PCR primer set and then a second-round amplification with Aspergillus-specific primers in tissues from six patients (Imhof et al. 2003). Different PCR reactions have been used to distinguish zygomycosis and invasive aspergillosis (IA) in paraffin-fixed tissues by Bialek et al. (2005). DNA was suc- cessfully amplified in 11 of 17 samples with histologically diagnosed IA, and 14 of 23 cases were histopathologically diagnosed as zygomycosis. In 2006, another group achieved a molecular fungal diagnosis in 52 of 57 (93%) cases (Paterson et al. 2006), and four groups have published their results previously (Lass-Flörl et al. 2007; Lau et al. 2007; Rickerts et al. 2007; Spiess et al. 2007) with the broad conclu- sions that multiple fungal pathogens can be detected, that the yield from fresh tissue is higher than from paraffin-embedded tissue, and that molecular methods are more sensitive than culture in identifying the causative fungus seen in tissue. Given these results, we investigated the utility of the new Received 24 January 2011. Revision received 7 June 2011. Accepted 7 June 2011. Published at www.nrcresearchpress.com/cjm on 23 August 2011. C. Lass-Flörl. Division of Hygiene and Medical Microbiology, Innsbruck Medical University, Fritz-Pregl-Straße 3, 6020 Innsbruck, Austria. S.A. Follett and A. Moody. Myconostica Ltd., South Court, Sharston Road, Manchester, M22 4SN, UK. D.W. Denning. Myconostica Ltd., South Court, Sharston Road, Manchester, M22 4SN, UK; National Aspergillosis Centre, University Hospital of South Manchester, University of Manchester, Manchester Academic Health Science Centre, Southmoor Road, Manchester, M23 9LT, UK. Corresponding author: C. Lass-Flörl (e-mail: cornelia.lass-floerl@i-med.ac.at). 765 Can. J. Microbiol. 57: 765–768 (2011) doi:10.1139/W11-064 Published by NRC Research Press Can. J. Microbiol. Downloaded from www.nrcresearchpress.com by UNIVERSITY OF MANCHESTER on 11/09/12 For personal use only.