TABLE 1.

Drug susceptibilities for recombinant HIV with site-directed mutations

Drug	EC50 (μM)a
	HXB2D (wild type)	K65R	K65RM184V
Tenofovir	3.1 ± 0.14	9.8 ± 1.2b (3.2)c	6.3 ± 0.94b (2.0)
ddI	4.3 ± 0.41	15.4 ± 2.7b (3.6)	29.5 ± 1.77b (6.9)
Abacavir	0.3 ± 0.02	1.1 ± 0.2b (3.8)	15.0 ± 0.001b (52.0)
DXG	1.9 ± 1.8	10.2 ± 2.2b (5.4)	8.0 ± 1.2b (4.2)
AZT	0.14 ± 0.02	0.07 ± 0.01 (0.5)	0.06 ± 0.01 (0.4)
d4T	7.5 ± 2.2	13.2 ± 2.5b (1.8)	10.4 ± 1.6d (1.4)

^aEC₅₀ for recombinant viruses were determined by an XTT-based viability assay with MT-2 cells, and averages ± standard errors for three to eight experiments are shown.

^bP < 0.001 compared to the EC₅₀ for the wild-type by two-tailed Student's t test.

^cThe values in parentheses are the fold change in the EC₅₀ for the mutant compared to that for the wild type.

^dP < 0.05 compared to the EC₅₀ for the wild type by two-tailed Student's t test.