title: Distinct behaviors of infectious F-specific RNA coliphage genogroups at a wastewater treatment plant.
abstract: The present study aimed to determine the differences in the behaviors of four F-specific RNA (F-RNA) coliphage genogroups (GI-GIV) during wastewater treatment. Raw sewage, aeration tank effluent, secondary-treated sewage, and return activated sludge were collected from a wastewater treatment plant in Japan at monthly intervals between March and December 2011 (n=10 each). F-specific coliphages were detected by plaque assay in all tested samples, with a concentration ranging from -0.10 to 3.66 log10 plaque-forming units/ml. Subsequently, eight plaques were isolated from each sample, followed by genogroup-specific reverse-transcription quantitative PCR (qPCR) for F-RNA coliphages and qPCR for F-specific DNA (F-DNA) coliphages. GI F-RNA coliphages were the most abundant in the secondary-treated sewage samples (73% of the plaque isolates), while GII F-RNA coliphages were the most abundant in the other three sample types (41-81%, depending on sample type). Based on the results of the quantification and genotyping, the annual mean concentrations of each F-specific coliphage type were calculated, and their reduction ratios during wastewater treatment were compared with those of indicator bacteria (total coliforms and Escherichia coli) and enteric viruses (human adenoviruses and GI and GII noroviruses). The mean reduction ratio of GI F-RNA coliphages was the lowest (0.93 log10), followed by those of the indicator bacteria and enteric viruses (1.59-2.43 log10), GII-GIV F-RNA coliphages (>2.60-3.21 log10), and F-DNA coliphages (>3.41 log10). These results suggest that GI F-RNA coliphages may be used as an appropriate indicator of virus reduction during wastewater treatment.
authors: International Research Center for River Basin Environment, Graduate Faculty of Interdisciplinary Research, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511, Japan. Electronic address: eharamoto@yamanashi.ac.jp.
authors: Eiji
authors: E
authors: Haramoto
authors: Department of Civil and Environmental Engineering, Faculty of Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511, Japan.
authors: Saki
authors: S
authors: Fujino
authors: International Research Center for River Basin Environment, Graduate Faculty of Interdisciplinary Research, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511, Japan.
authors: Mikie
authors: M
authors: Otagiri
mesh_terms: D003090:Coliphages / Q000145:classification* / Q000235:genetics; D005838:Genotype; D007564:Japan; D012313:RNA; D014865:Waste Disposal, Fluid; D062065:Wastewater / Q000821:virology*; D014871:Water Microbiology
chemical_list: D012313:RNA; D062065:Wastewater
keywords: F-specific coliphage; Human enteric virus; Indicator bacteria; Wastewater treatment