Comparison of filters for concentrating microbial indicators and pathogens in lake-water samples

Applied and Environmental Microbiology
By: , and 



Bacterial indicators are used to indicate increased health risk from pathogens and to make beach closure and advisory decisions; however, beaches are seldom monitored for the pathogens themselves. Studies of sources and types of pathogens at beaches are needed to improve estimates of swimming-associated health risks. It would be advantageous and cost-effective, especially for studies conducted on a regional scale, to use a method that can simultaneously filter and concentrate all classes of pathogens from the large volumes of water needed to detect pathogens. In seven recovery experiments, stock cultures of viruses and protozoa were seeded into 10-liter lake water samples, and concentrations of naturally occurring bacterial indicators were used to determine recoveries. For the five filtration methods tested, the highest median recoveries were as follows: glass wool for adenovirus (4.7%); NanoCeram for enterovirus (14.5%) and MS2 coliphage (84%); continuous-flow centrifugation (CFC) plus Virocap (CFC+ViroCap) for Escherichia coli (68.3%) and Cryptosporidium (54%); automatic ultrafiltration (UF) for norovirus GII (2.4%); and dead-end UF for Enterococcus faecalis (80.5%), avian influenza virus (0.02%), and Giardia (57%). In evaluating filter performance in terms of both recovery and variability, the automatic UF resulted in the highest recovery while maintaining low variability for all nine microorganisms. The automatic UF was used to demonstrate that filtration can be scaled up to field deployment and the collection of 200-liter lake water samples.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Comparison of filters for concentrating microbial indicators and pathogens in lake-water samples
Series title Applied and Environmental Microbiology
DOI 10.1128/AEM.03117-12
Volume 79
Issue 4
Year Published 2013
Language English
Publisher American Society for Microbiology
Publisher location Washington, D.C.
Contributing office(s) National Wildlife Health Center, Ohio Water Science Center
Description 11 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Applied and Environmental Microbiology
First page 1342
Last page 1352
Country United States
State Michigan, New York, Ohio, Wisconsin
Online Only (Y/N) N
Additional Online Files (Y/N) N
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