PCR AND GENE PROBES FOR DETECTING BIOAEROSOLS

Current methods for analyzing bioaerosols are based on maintaining organism viability and quantifying culturability; this can result in underestimation of concentrations. A feasibility study investigated a new analytical technique that only requires intact cellular DNA to identify organisms. This technique uses the polymerase chain reaction (PCR) to amplify specific DNA sequences from an organism, and hybridization of PCR product with DNA probes, to detect and quantify organisms. Legionella pneumophila solutions were aerosolized in a chamber, and air samples were collected using impingers and membrane filters. Samples were analyzed using the PCR-gene probe technique and gel electrophoresis. Results were compared with traditional plate counting and direct microscopic counts of cells stained with acridine orange. Results indicated that the PCR-gene probe technique provides a new way to identify and quantify bioaerosols that does not rely on viability and culturability. Therefore, the method would provide a more reliable estimate of airborne bacterial concentrations compared to traditional plate counts.