Superiority of infectivity-based over particle-based methods for quantitation of drug resistant HIV-1 as inocula for cell cultures.

Performance of phenotypic assays and replication capacity assays require normalization of virus input. Therefore, quantitation of HIV-1 in supernatants to inoculate cell cultures is an important step. Since the gold standard for the determination of infectivity, the tissue culture infectious dose 50% (TCID50) is time-consuming, several other methods are in use.

No evidence for persistence of multidrug-resistant viral strains after a 7-month treatment interruption in an HIV-1-infected individual.

The number of HIV-1-infected patients harboring multidrug-resistant viruses is increasing. Since new antiretroviral drugs with favorable resistance profiles are limited, innovative strategies are urgently needed. Treatment interruptions can lead to a loss in HIV resistance followed by improved response to reinitiated therapy.

Prediction of abacavir resistance from genotypic data: impact of zidovudine and lamivudine resistance in vitro and in vivo.

Abacavir is frequently used in antiretroviral combination therapies as a potent nucleoside reverse transcriptase inhibitor (NRTI). Four mutations are selected for by abacavir in vitro and in vivo: K65R, L74V, Y115F, and M184V. Abacavir resistance has also been observed in NRTI multidrug-resistant samples.