TABLE 1.

Polymerase mutations selected by serial passage in ribavirin

Parental virus phenotype	Lineage	P10e mutation(s)a
WT	1	None
	2	None
	3	None
G64S	1	None
	2	None
	3	None
G64Fix	1	None
	2	None
	3	3Dpol M392V and C→U6163
D79H	1	None
	2	3Dpol T353I
	3	None
L419A	1	None
	2	None
	3	3Dpol G64S
L420A	1	3Dpol L420V and M299I
	2	3Dpol L420V and 3Cpro A172S
	3	3Dpol L420I and M323I
G64Fix L420A	1	3Dpol L420 reversion, M323I, and C→U6163
	2	3Dpol L420 reversion
	3	3Dpol L420 reversion and G64S
G64S L420A	1	3Dpol L420 reversion
	2	3Dpol L420 reversion
	3	3Dpol L420 reversion

^aPoliovirus recovered from passage 10 (Fig. 2 and 3) was expanded by infecting a T150 flask of HeLa cells. The 3D^pol region of expanded P10 virus (P10^e) was converted to cDNA and sequenced.