The Gram-positive bacterium, Staphylococcus aureus can survive in indoor environments in the community, such as schools and homes, contributing to public health concerns related to human exposure and ..
The Gram-positive bacterium, Staphylococcus aureus can survive in indoor environments in the community, such as schools and homes, contributing to public health concerns related to human exposure and transmission. While convenient methods that do not require refrigeration or surface wetting have been described for identification of environmental S. aureus, these methods currently only provide a positive or negative result. Therefore, the goal of this project was to adapt and validate a dry collection method to provide quantification of S. aureus from indoor environmental samples comparing culture-based and culture-independent approaches, and then apply this method to environmental surface samples from local schools. For this project, S. aureus ATCC43300 was inoculated onto autoclaved Swiffer cloths. Then, S. aureus colonies were extracted from the cloths in 100ml of 1x solution phosphate buffered saline (PBS), the PBS extract was concentrated by vacuum filtration, and colony forming units (CFUs) enumerated on CHROMagar staph agar. S. aureus was successfully enumerated from experimentally-inoculated cloths. The findings from this work demonstrate that S. aureus can be recovered and quantified from dry cloth surface samples. This work also displays that the culture independent method was optimum for extraction efficiency and ease of use. This work highlights the importance of methodological development for S. aureus exposure assessment from indoor community environments.