Comparative activity of selected antiviral compounds against clinical isolates of human cytomegalovirus.

Seventeen fresh clinical isolates of human cytomegalovirus (HCMV) were examined for their in vitro susceptibility to different potential anti-HCMV drugs, including a series of acyclic nucleoside phosphonate analogues as well as the reference compounds ganciclovir, foscarnet and acyclovir. Three sulfated polysaccharides (heparin, dextran sulfate and pentosan polysulfate) known for their ability to inhibit adsorption of enveloped viruses to the cells were also included in these comparative tests. Of the reference compounds, ganciclovir was the most potent. However, it was about five-fold less potent than the phosphonate derivative (s)-1-(3-hydroxy-2-phosphonylmethoxypropyl)cytosine (HPMPC) and its cyclic form (cHPMPC). All test compounds, including the sulfated polysaccharides, were as active against the clinical isolates as they were against the laboratory strains of HCMV. Furthermore, the choice of the cell line (HEL or MRC-5) did not influence the anti-HCMV activity of the compounds.