Methods for detecting microorganisms on surfaces are needed to locate biocontamination sources and to relate surface and airborne concentrations. Research was conducted in an experimental room to evaluate surface sampling methods and quantitative PCR (QPCR) for enhanced detection of a target biocontaminant present on flooring materials. QPCR and culture analyses were used to quantitate Bacillus subtilis (Bacillus globigii) endospores on vinyl tile, commercial carpet, and new and soiled residential carpet with samples obtained by four surface sampling methods: a swab kit, a sponge swipe, a cotton swab, and a bulk method. The initial data showed that greater overall sensitivity was obtained with the QPCR than with culture analysis; however, the QPCR results for bulk samples from residential carpet were negative. The swab kit and the sponge swipe methods were then tested with two levels of background biological contamination consisting of Penicillium chrysogenum spores. The B. subtilis values obtained by the QPCR method were greater than those obtained by culture analysis. The differences between the QPCR and culture data were significant for the samples obtained with the swab kit for all flooring materials except soiled residential carpet and with the sponge swipe for commercial carpet. The QPCR data showed that there were no significant differences between the swab kit and sponge swipe sampling methods for any of the flooring materials. Inhibition of QPCR due solely to biological contamination of flooring materials was not evident. However, some degree of inhibition was observed with the soiled residential carpet, which may have been caused by the presence of abiotic contaminants, alone or in combination with biological contaminants. The results of this research demonstrate the ability of QPCR to enhance detection and enumeration of biocontaminants on surface materials and provide information concerning the comparability of currently available surface sampling methods.Human exposure to bioaerosols has been associated with a variety of diseases, and dissemination of microbial contaminants in indoor environments has been linked to the development of a cluster of symptoms that include eye and sinus irritation, sore throat, headache, fatigue, and dizziness (11). Contamination and subsequent dispersal of biocontaminants in the workplace and living quarters provide an environment that increases the possibility of occupant exposure and adverse health effects ranging from lost productivity to severe illness. Detection and measurement of biocontaminants in indoor environments are needed to assess contamination levels and to estimate the resulting exposure of occupants. However, monitoring is hampered by a lack of methods that provide precise, accurate, and representative exposure estimates for bioaerosols and microbe-contaminated surfaces (3). Conventional biocontaminant monitoring relies on collection of airborne and surface microorganisms and analysis of samples either by culturing on artificial growth media or by micro...

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