Variations in the cytomegalovirus major immediate-early gene found by direct genomic sequencing.

An assay to detect and sequence DNA from human cytomegalovirus (HCMV) immediate-early gene region 1 has been developed; it involves in vitro amplification by the polymerase chain reaction and direct solid-phase sequencing of the amplified material. Urine samples from 16 patients tested positive for HCMV DNA in both a colorimetric assay for the detection of immobilized amplified nucleic acids and a standard polymerase chain reaction assay with agarose gel electrophoresis. Ten urine samples from healthy people tested negative in the same assays. Analysis of 106-bp fragments from seven patients and two laboratory HCMV strains (Ad 169 and Towne) demonstrated that the viral sequences were conserved in samples collected at different times from the same patient and in tissue-cultured samples. Two of the patient strains had variations in the amplified region, with a total of seven nucleotide substitutions yielding five amino acid alterations in the coding sequence.