Increased Detection of Enteroviruses and Adenoviruses from Archived Samples of a U.S. Groundwater Survey, Using Integrated Cell Culture Real-time PCR Assays
Brandon C. Iker1, Masaaki Kitajima1, Absar Alum2, Morteza Abbaszadegan2, Charles Gerba1, Ian L. Pepper1
1 Soil Water Environmental Science Department, University of Arizona, 2School of Sustainable Engineering and the Built Environment,
Arizona State University
The detection of fecal contamination in groundwater is necessary to insure safe drinking water by mitigating the risk of illness in service areas. The present study was designed to reassess the presence of enteroviruses (EVs) and adenoviruses (AdVs) in a subset of archived samples of a landmark US groundwater survey using highly sensitive integrated cell culture real-time PCR (ICC-rtPCR) assays. We randomly selected 51 cytopathogenic effect (CPE)-negative samples from the original 488 samples and performed ICC-rtPCR. Out of the 51 samples tested, 23 (45%) and 14 (27%) samples were positive by ICC-rtPCR assays for EVs and AdVs, respectively, although only 8 (16%) samples were positive for EVs by the direct RT-PCR assay applied to the original concentrates in our previous study. The results suggest that ICC-rtPCR assay utilized in this study is more sensitive than the direct PCR assay used in the past. One of the important findings of the present study is the occurrence of AdVs in groundwater in the US, which is not been well studied. In addition, our results demonstrate that the previous study may underestimate the occurrence of potentially viable enteric viruses, especially when present in low concentrations.