, David Polo12
, Cecile Le Mennec, Sofia Strubbia3
, Xi-Lei Zeng, Khalil Ettayebi, Robert L. Atmar, Mary K. Estes, and Françoise S. Le Guyader
Figure 2. Persistence of viral RNA and infectious norovirus and Tulane virus in seawater. Concentration of viral RNA measured by quantitative reverse transcription PCR (qRT-PCR) in seawater (circles, RNA copies/mL), and of infectious TuV measured by TCID50 (cross, TCID50/mL), during experiments 1 (A), 2 (B), and 3 (C). Open circles mark the detection of infectious virus on HIE cells (human norovirus) or through TCID50 on LLC-MK2 cells (TuV). Black circles indicate the absence of infectious virus detection. Dotted lines indicate the theoretical LoD of the TCID50 assay (5 TCID50/mL). D) Recovery of the viral genome after purification and concentration steps, defined as the ratio (%) of viral genome in the concentrate to that in the seawater, as measured by qRT-PCR, for each virus and time point during the 3 experiments. Black lines indicate the mean per experiment and virus. Recovery was not statistically different between experiments and viruses except for TuV and norovirus GII.3 during experiment 2 (analysis of variance, Sidak’s multiple comparisons test; *p = 0.0318) (GraphPad Prism version 9.2.0, https://www.graphpad.com/scientific-software/prism). LoD, limit of detection; NoV, norovirus; TCID50, 50% median tissue culture infectious dose; TuV, Tulane virus.