TABLE 3.
Phenotypic analysis of resistance of South African isolates and reference strain HXB2/NL4-3-PR to NL4-3 each commercially available PI
| Isolatea | Fold resistance
|
||||
|---|---|---|---|---|---|
| IDV (3.0)c | RTV (3.5) | NFV (4.0) | SQV (2.5) | APV (2.5) | |
| L45 | 1b | 0.5 | 0.5 | 0.8 | 0.9 |
| MD | 1 | 0.7 | 0.7 | 0.6 | 0.68 |
| PT02 | 1.3 | 1.2 | 0.5 | 0.8 | 0.8 |
| L14 | 1 | 0.5 | 0.3 | 0.4 | 1 |
a
All isolates had the I93L mutation.
b
Fold resistance compared to that of pNL4-3 (IC50s for pNL4-3, indinavir [IDV], 12 nM; ritonavir [RTV], 47 nM; nelfinavir [NFV], 62 nM; saquinavir [SQV], 12 nM; amprenavir [APV], 100 nM).
c
The values in parentheses are the biological cutoffs generated by Harrigan et al. (6) by a similar phenotyping technology. The values are expressed as fold resistance compared to that of pNL4-3. The cutoff for lopinavir was not determined in this study.