A NOVEL-APPROACH TO ASSESSING THE DRUG SUSCEPTIBILITY AND REPLICATIONOF HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 ISOLATES

Human immunodeficiency virus type 1 (HIV-1) drug susceptibility testin g is often curtailed because such testing is expensive and time consum ing. A colorimetric tetrazolium dye method previously used for high-th roughput antiviral drug screening was adapted to assess the susceptibi lity of 16 HIV-1 isolates to zidovudine, didanosine, lamivudine, and n evirapine in MT-2 cells. Cell viability was assessed colorimetrically, and all measurements and calculations were automated. Each HIV-1 isol ate was tested in greater than or equal to 5 assays to determine the r eproducibility of the assay in HIV-1 isolates with known reverse-trans criptase mutations. The drug susceptibility of several mutant HIV-1 st rains whose drug susceptibilities had not previously been well defined was also determined. Data on HIV-1 replication from the susceptibilit y assays indicated that some mutant HIV-1 isolates may have been less cytopathic in MT-2 cells than wild type HIV-1 isolates.