Indoor fungal contamination of moisture-damaged and allergic patient housing analysed using real-time PCR

AIMS: The aim of our study was to compare, using real-time (Rt) PCR, quantitative levels of five fungal species in three kinds of dwellings. METHODS AND RESULTS: Three groups of homes were recruited: moisture-damaged homes (MDH, n = 30), allergic patient homes (APH, n = 25) and paired control homes (CH, n = 55). Five moulds with allergenic compounds or mycotoxin production characteristics (Cladosporium sphaerospermum, Penicillium chrysogenum, Aspergillus versicolor, Alternaria alternata and Stachybotrys chartarum) were quantified using Rt-PCR. Cycle threshold results were expressed in spore equivalent per volume or surface unit using a direct calculation based on a spore standard curve. MDH presented significantly higher amounts of DNA from C. sphaerospermum in both air and surface samples than CH (P < 0.001). APH presented slightly elevated amounts of DNA from A. versicolor in both air and surface samples, compared to CH (P < 0.05). CONCLUSION: Rt-PCR quantification of targeted fungal species is a rapid, reliable tool that could be included in a global indoor mould evaluation. SIGNIFICANCE AND IMPACT OF THE STUDY: Quantification of C. sphaerospermum using Rt-PCR can help to better target social service intervention in MDH. Quantification of A. versicolor DNA could be informative for characterization of APH.