Table 3. Drug susceptible analysis of representative HBV strains.
| Viral strain | Entecavir | Tenofovir | ||
|---|---|---|---|---|
| EC50 (μmol/L) | Fold | EC50 (μmol/L) | Fold | |
| Wild-type 1 | 0.004 ± 0.006 | 1.0 | 1.828 ± 0.926 | 1.0 |
| rtL180M+A181C+M204V | 0.357 ± 0.083 | 85.6 | 5.453 ± 1.004 | 3.0 |
| rtL180M+A181C+M204V+M250V | 1.487 ± 0.219 | 356.1 | 4.927 ± 0.971 | 2.7 |
| rtL180M+A181C+S202G+M204V | 1.282 ± 0.495 | 307.1 | 5.904 ± 2.062 | 3.2 |
| rtL180M+A181V+M204V | 0.060 ± 0.035 | 15.0 | 13.002 ± 3.584 | 7.1 |
| rtL180M+M204V(lab) | 0.075 ± 0.036 | 17.9 | 3.090 ± 0.928 | 1.7 |
| Wild-type 2 | 0.003 ± 0.001 | 1.0 | 0.710 ± 0.220 | 1.0 |
| rtL180M+S202G+M204V | 0.413 ± 0.454 | 137.7 | 1.548 ± 0.328 | 2.2 |
| rtL180M+T184A+M204V | 0.331 ± 0.744 | 110.4 | 1.426 ± 0.306 | 2.0 |
Notes: EC50: the 50% effective concentration of drug. Fold: the EC50 of mutant/the EC50 of wild-type. Wild-type 1 and four subsequent mutant strains were derived from serial serum samples of an rtA181C-positive patient. rtL180M+M204V(lab) was a laboratory strain created by eliminating rtA181C mutation from the rtL180M+A181C+M204V mutant. Wild-type 2 and two subsequent classical entecavir-resistance mutant strains were derived from another entecavir-refractory patient.