Submitted to: Journal of Visualized Experiments
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/30/2012
Publication Date: 3/3/2012
Citation: Millen, H., Gonnering, J., Berg, R., Spencer, S.K., Jokela, W.E., Pearce, J.M., Borchardt, J.S., Borchardt, M.A. 2012. Glass wool filters for concentrating waterborne viruses and agricultural zoonotic pathogens. Journal of Visualized Experiments. DOI: 10.3791/3930. Interpretive Summary: The key first step in evaluating pathogen levels in suspected contaminated water is concentration. Our research group has extensively validated the use of glass wool filtration for concentrating waterborne pathogens. As a leader in developing this method we receive many requests from around the world to supply research teams with glass wool filters. Constructing the filters is very easy; any research laboratory can do it and it is not necessary to rely on our group as a filter supplier. Abiding by the tenet of the Journal of Visualized Experiments, that it is easier to learn a scientific method by watching instead of reading, we have created an eight minute video that shows step-by-step how to construct a glass wool filter. The video is accompanied by detailed written instructions and a parts list. In addition, we report results showing that the filter is very effective in concentrating the types of pathogens in livestock that can also infect people. We also discuss the history of glass wool filtration in water microbiology and the method limitations compared to other approaches.
Technical Abstract: The key first step in evaluating pathogen levels in suspected contaminated water is concentration. Concentration methods tend to be specific for a particular pathogen group or genus, for example viruses or Cryptosporidium, requiring multiple methods if the sampling program is targeting more than one pathogen type. Another drawback of current methods is the equipment can be complicated and expensive. In this article we describe how to construct glass wool filters for concentrating waterborne pathogens. After filter elution, the concentrate is amenable to a second concentration step, like centrifugation, followed by pathogen detection and enumeration by cultural or molecular methods. The filters have several advantages. Construction is easy and the filters can be built to any size for meeting specific sampling requirements. The filter parts are inexpensive, making it possible to collect a large number of samples without severely impacting a project budget. Large sample volumes, hundreds to thousands of liters, can be concentrated, depending on sample turbidity. The filters are highly portable and with minimal equipment, such as a pump and flow meter, they can be implemented in the field for sampling finished drinking water, surface water, groundwater, and agricultural runoff. Lastly, glass wool filtration is effective for concentrating a variety of pathogen types so only one method is necessary. Here we report on filter effectiveness in concentrating waterborne human enterovirus, Salmonella enterica, Cryptosporidium parvum, and avian influenza virus.