SINGLE AMINO-ACID CHANGE IN DNA-POLYMERASE IS ASSOCIATED WITH FOSCARNET RESISTANCE IN A VARICELLA-ZOSTER VIRUS-STRAIN RECOVERED FROM A PATIENT WITH AIDS

The genetic characterization of a foscarnet-resistant strain of varice lla-zoster virus (VZV) that was isolated from a patient with AIDS is r eported. Compared with the sequence of the Dumas reference strain, thi s strain, which was isolated from a patient in whom foscarnet treatmen t failed, had two point mutations. The emergence of one of the mutatio ns, which includes a change from a glutamic acid to a lysine at positi on 512 in the DNA polymerase, suggests that this mutation is implicate d in the VZV foscarnet resistance. The other mutation, which replaces serine 863 by a glycine, is also present in 2 susceptible strains-Oka and a wild-type isolate.