Effective concentration, recovery, and detection of infectious adenoviruses from environmental waters

Current application of fecal indicator bacteria (FIB) as an indicator of sewage contamination has its limitation and other alternative indicator systems are needed for enhanced monitoring of recreational water quality. To explore the potential use of human enteric viruses (HEV) as a potential indicator, human adenovirus type 7 (HAdV-7) was tested in this study as a model virus. Through spiked HAdV-7 into the sample seawater, different procedures for viral concentration and elution were comparatively analyzed in a side-by-side fashion. Nearly 80% infectious viruses were recovered from the spiked seawater with the use of a magnetic stirring method and 1.0 mM NaOH as elution buffer. A viral plaque assay was established with optimized conditions for the detection and quantification of infectious HAdV and used to determine the stability of HAdV-7 in seawater and a possible correlation for HAdV detection between the viral infectivity assay and PCR. Findings from this study suggest it is possible to concentrate and recover infectious HAdV from environmental waters effectively with optimized laboratory conditions, which warrants the future test and establishment of using HEV as an alternative indicator of water quality.