TABLE 2.

Amino acid substitutions in the HIV-1 protease sequences of isolates from 142 treatment-naive patients at key positions associated with resistance to available drugs

Subtype	No. of strains	Mutation(s) in the protease at key positions in the following wild-type amino acids and positions:
		L10	K20	L33	M36	M46	L63	A71	V77	V82
A	9	I3a, V1	R1, I1		I9		P1, Q1
B	13						P6, S1, H1		I3
C	2		R1		I2		T1, S1
D	5	V1			I3		P1, S1
F1 + F2	11	V4	R8, I1		I11	I1	P3, T2, S1, V1
G	4	I1	I4		I4		P1			I4
K	2	I1, V1	R2		I2		C1
J	5	I2, V1			I3		T2, I1		I1
CRF02-AG	67	I3, V6	M1, I63, V2	F1	I67		P2, S3, F1, V1, I3, N1		I4	I3
CRF01-AE	3	V1			I3		C1
A/G	6	I2	I6		I6		S1, I1, N1
G/A/G	2		I2		I2		M1			I2
G/K	2		I2		I2		P1
D/G/D	1				I1
?/K	4	I2, V2	R1		I3		S1
Ub	2	I1, V1	R2		I1		T1, V1
Group O	4	I2, V2	C4		I4		P3, T1	V4
Total	142	I17, V20	M1/R15, I79, V2/C4	F1	I123	I1	P18, Other32	V4	I8	I9

^aThe letter represents the amino acid substitution, and the number indicates the number of strains with this mutation. Amino acids in boldface type are associated with resistance to PIs. 

^bU, unknown subtypes.