IRES activity measured after transitory transfection of pCREL vectors in HuH7 and HeLa cells, expressed in arbitrary units (AU). Vertical bars represent standard deviations of the means from triplicate measures. (A) CRH (negative control), HRV (human rhinovirus), HM-175 strain (G1RW), HM-175/18f (G1RC), and studied clinical isolates (G1, G2, or G3 for genotype I, II, or III and B, S, or F for benign, severe, or fulminant hepatitis, respectively). (B) CRH (negative control); HM-175 (G1RW); HM-175 with T255C and T278C mutations, present in the G1B5 strain (RW-B5); HM-175 with G324 and C372 mutations (RW-FUJ).