Molecular quantitative analysis of human viruses in California storm water

V. B. RAJAL; B.S. MCSWAIN; D.E. THOMPSON; C.M. LEUTENEGGER; S. WUERTZ

WATER RESEARCH

Elsevier

Año: 2007 vol. 41 p. 4287 - 4298

0043-1354

Many human viruses are transmitted via the oral-fecal route and water is one possible vehicle, representing a risk for public health. Sixty one large-volume water samples from storm drains in California were processed by a two-step hollow fiber ultrafiltration procedure followed by molecular analysis for human enterovirus and adenovirus types. Each sample was spiked with a surrogate, the benign bacteriophage PP7. Both surrogate and human viruses were quantified by newly designed Taqman PCR assays.  Equations were developed that account for the main variables in the procedure, recovery of the ultrafiltration, efficiency of nucleic acid extraction, and effect of inhibitors on the amplification of viral targets. Adenovirus 40/41 was detected in one sample at 230 genomes per liter and no other adenovirus or enterovirus type was found. Samples that resulted in nondetects are reported together with the corresponding sample-specific limit of detection (SLOD), a useful tool when estimating the public health risk associated with the contact or ingestion of water. Neither virus concentrations nor SLOD correlated with traditional viable indicator concentrations or any of the physicochemical parameters measured.  In contrast coliform concentrations were correlated with total suspended solids. To our knowledge this is the first study where all factors known to influence limits of detection have been investigated and integrated into equations that are widely applicable to the quantification of viruses or other microbial targets by PCR.