Fig 1. Selection for West Nile virus populations with decreased susceptibility to ribavirin.
A. Ribavirin susceptibility, measured as mean log10 pfu/ml reduction in viral titer +/- SD resulting from 50uM ribavirin treatment for 72h on Hela cell culture relative to untreated controls, following passage of parallel series of ribavirin-treated WNV-IC designated as lineage I (black) and lineage II (grey). B. Ribavirin susceptibility in selected clonal populations. Clonal populations were created with lineage I from 20 plaques isolations (pp) and strains with the highest levels of resistance (WNV pp3/9) were chosen for further characterization.