Passive sampling of microbes in various water sources: A systematic review
Elnaz Karamati N., Ilya Law, J. Scott Weese, David McCarthy, Heather Murphy
Abstract
• Membrane filters are effective for detection and quantification of viruses in wastewater • Gauze passive samplers coupled with culturing is effective for detection of bacteria • Studies on passive sampling of protozoa in any water source are needed • Passive sampling papers in groundwater and seawater are lacking • Quantification and accumulation studies are needed Traditional methods for monitoring pathogens in environmental waters have numerous drawbacks. Sampling approaches that are low-cost and time efficient that can capture temporal variation in microbial contamination are needed. Passive sampling of aquatic environments has shown promise as an alternative water monitoring technique for waterborne pathogens and microbial contaminants. The present systematic review aimed to compile and synthesize existing literature on the use of passive samplers for the monitoring of microbes in different water sources and identify research gaps. The review summarizes current knowledge on materials used for detection, deployment durations, analytical methods, quantification as well as benefits and limitations of passive sampling. This review found that electronegative nitrocellulose membrane filters are effective for both detection and quantification of viruses in wastewater, while gauze passive samplers have been effective for detecting bacterial targets in wastewater. There is a large knowledge gap in the use of passive samplers in a quantitative manner, especially for the back-calculation of water-column microbial concentrations or for correlation to outcomes of interest (e.g. prevalence rates). Further, there is very limited attensstion paid to the use of membrane filters for the monitoring of bacteria in any water source as well as a lack of studies utilizing passive sampling approaches for protozoa.