Human adenoviruses and coliphages in urban runoff-impacted coastal waters of Southern California

A nested-PCR method was used to detect the occurrence of human adenovirus i n coastal waters of Southern California. Twenty- to forty-liter water sampl es were collected from 12 beach locations from Malibu to the border of Mexi co between February and March 1999. All sampling sites were located at mout hs of major rivers and creeks. Two ultrafiltration concentration methods, t angential flow filtration (TFF) and vortex how filtration (VFF), were compa red using six environmental samples. Human adenoviruses were detected in 4 of the 12 samples tested after nucleic acid extraction of VFF concentrates. The most probable number of adenoviral genomes ranged from 880 to 7,500 pe r liter of water. Coliphages were detected at all sites, with the concentra tion varying from 5.3 to 3332 PFU/liter of water. F-specific coliphages wer e found at 5 of the 12 sites, with the concentration ranging from 5.5 to 30 0 PFU/liter. The presence of human adenovirus was not significantly correla ted with the concentration of coliphage (r = 0.32) but was significantly co rrelated (r = 0.99) with F-specific coliphage. The bacterial indicators (to tal coliforms, fecal coliforms, and enterococci) were found to exceed Calif ornia recreational water quality daily limits at 5 of the 12 sites. However , this excess of bacterial indicators did not correlate with the presence o f human adenoviruses in coastal waters. The results of this study call for both a reevaluation of our current recreational water quality standards to reflect the viral quality of recreational waters and monitoring of recreati onal waters for human viruses on a regular basis.