Comparison of BGM and PLC/PRC/5 Cell Lines for Total Culturable Viral Assay of Treated Sewage

Department of Soil, Water, and Environmental Science, University of Arizona, P.O. Box 210038. Tucson, Arizona 85721-0038

^* To whom correspondence should be addressed. Email: gerba{at}ag.arizona.edu.

	Abstract

The objective of this study was to compare PLC/PRF/5 and BGM cell lines for Total Culturable Viral Assay (TCVA) analysis of treated sewage effluents. Samples were collected before and after chlorination from an activated sludge wastewater treatment plant and from the effluent of a high-rate enhanced flocculation system followed by UV light disinfection. Cell monolayers were observed for cytopathic effect (CPE) after two passages of 14 days each. Monolayers exhibiting viral CPE were tested for the presence of adenoviruses and enteroviruses by polymerase chain reaction (PCR) or reverse transcription-PCR (RT-PCR). Eight percent (8%) of the samples exhibited CPE on BGM cells, and 57% on PLC/PRF/5 cells. Only enteroviruses were detected on the BGM cells, while 30% and 52% of the samples were positive for enteroviruses and adenoviruses, respectively on the PLC/PRF/5 cells. Thirty percent (30%) of the samples were positive for both adenoviruses and enteroviruses in chlorinated activated sludge effluent. Thirty percent (30%) of the samples were positive for adenoviruses in the UV treatment effluent but no enteroviruses were detected. In conclusion, the PLC/PRF/5 cells were more susceptible to viruses found in treated sewage than BGM cells. The use of BGM cells for TCVA may underestimate viral concentration in sewage effluent samples. The PLC/PRF/5 cells were more susceptible to adenoviruses, which is important in the evaluation of UV disinfection systems because adenoviruses are highly resistant to UV inactivation.