Fuhrman JA, Liang X, Noble RT. Rapid detection of enteroviruses in small volumes of natural waters by real-time quantitative reverse transcriptase PCR.
Appl Environ Microbiol 2005;
71:4523-30. [PMID:
16085845 PMCID:
PMC1183282 DOI:
10.1128/aem.71.8.4523-4530.2005]
[Citation(s) in RCA: 83] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Despite viral contamination of recreational waters, only bacterial, not viral, indicators are monitored routinely, due to a lack of rapid and cost-effective assays. We used negatively charged filters to capture enteroviruses from seawater and freshwater. Viral RNA was extracted using a commercial kit, and the viruses were quantified by real-time quantitative reverse transcriptase PCR (qRT-PCR). Poliovirus (6.6 to 330,000 virus particles/ml) was added to samples from watersheds in Los Angeles, California, and analysis showed that with 50-ml samples, a cellulose acetate/nitrate (HA) filter yielded final recovery of 51% (r2= 0.99) in fresh water and 23% (r2= 0.90) in seawater. However, for additions of low levels of virus (more likely to represent field samples; <10(4) enterovirus particles/ml), the recovery was lower and more variable, with HA being best in freshwater (17%, r2= 0.97) and the type GF/F glass filter having higher average recovery in seawater (GF/F, 17%; r2= 0.93; HA 12%, r2= 0.87). The optimized method was used with 1-liter field samples from two very different freshwater "creeks" that drain into Santa Monica Bay, California: Topanga Creek (TC), a relatively pristine mountain creek, and Ballona Creek (BC), a concrete-lined urban storm drain. One TC site out of 10 and 2 BC sites out of 7 tested significantly positive for enteroviruses, with higher enterovirus concentrations in BC than in TC (ca. 10 to 25 versus 1 equivalent enterovirus particle/ml). The presented filtration-qRT-PCR approach is fast (<8 h from sampling to results), sensitive, and cost efficient and is promising for monitoring viral contamination in environmental water samples.
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