THE USE OF DNA TESTING IN MOULD INVESTIGATIONS ANN DORTE PØRNEKI, M.SC.

Transcription

1 THE USE OF DNA TESTING IN MOULD INVESTIGATIONS ANN DORTE PØRNEKI, M.SC.

2 EXPERIENCES FROM SCANDINAVIA Many years with strict insulation requirements Increase in number of damp and mouldy buildings Airtight buildings result in greater exposure to indoor pollutants 90s-00s increased public and scientific awareness on the health effects Insulations and increased building complexity often results in moulds growing out of sight (three out of four cases - Danish Technological Institute)

3 EXPERIENCES FROM SCANDINAVIA TRADITIONAL METHODS Culture-based Only viable spores - can t detect dried out infestations Low sensitivity Low reproducibility Enzyme-based No species identification - Can t distinguish between indoor and outdoor sources

4 EXPERIENCES FROM SCANDINAVIA HouseTest was founded in 2011 to develop a DNA test able to detect and quantify mould and bacteria in buildings growing out of sight, while also being able to distinguish between indoor and outdoor sources

5 DNA TESTING Sampling Spores, hyphae and microparticles contain DNA

6 DNA TESTING Laboratory Lysis of spores to release DNA Purification Quantitative polymerase chain reaction (qpcr) detect and quantify fungal and bacterial DNA

7 DNA TESTING 24 species of moulds, bacteria and pollen Aspergillus niger Chaetomium globosum Cladosporium cladosporides Cladosporium herbarum Pen/Asp/Pae grp. Stachybotrys chartarum Streptomyces spp. Aspergillus versicolor Acremonium strictum Alternaria alternata Cladosporium sphaerospermum Aspergillus glaucus grp. Universal fungi Mucor/Rhizopus grp. Penicillium chrysogenum Rhizopus stolonifer Aspergillus fumigatus Tricoderma viride Ulocladium chartarum Wallemia sebi Penicillium expansum Alnus/corylus spp Betula spp. Poeceae spp. High moisture indicator Chaetomium globosum Stachybotrys chartarum Tricoderma viride Ulocladium chartarum Panel Low/fluctuating moisture levels Aspergillus niger Pen/Asp/Pae grp. Streptomyces spp. Aspergillus versicolor Acremonium strictum Cladosporium sphaerospermum Aspergillus glaucus grp. Universal fungi Mucor/Rhizopus grp. Penicillium chrysogenum Rhizopus stolonifer Aspergillus fumigatus Wallemia sebi Penicillium expansum Outdoor species Cladosporium cladosporides Cladosporium herbarum Alternaria alternata Pollen Alnus/corylus spp Betula spp. Poeceae spp. Determining species composition is essential to distinguish between indoor and outdoor sources!

8 DNA TESTING Pitfalls Age of dust Distinguishing between indoor and outdoor sources - knowledge on the local outdoor microbial composition Distinguishing between hazardous and non hazardous profiles

9 FROM SPORE COUNTS TO CONCLUSION

10 PCA RESEARCH PROGRAMME Monitoring air quality in dwellings Air- and dust samples from 30 homes across UK Outdoor air samples Unique database to UK background levels

11 PCA RESEARCH PROGRAMME Preliminary results Same outdoor species (in similar numbers) as seen in Scandinavia Correlation between visible moulds and moisture indicators identified Hidden mould found in 2 of 5 buildings without visible infestations

12 DNA TESTING Uses Screening buildings suspected to have hidden mould infestations Localizing the infestation Overview of large buildings Determine spread from adjacent parts of the building Assessing mould removal and redevelopment

13 CASES Old dust vs. mould infestation mould infestation old dust

14 CASES Spread from basement to living area Basement Living area

15 FUTURE OF DNA TESTING Incorporate data from the PCA study Investigate the correlation between the species composition and health effects Adding new targets to the test: bacteria, mites and other fungi