Full genome sequencing and analysis of human cytomegalovirus strain JHC isolated from a Korean patient

Human cytomegalovirus (HCMV) is a ubiquitous human pathogen and contains double stranded DNA genome with approximately 230 kbp. Because of its huge size, comparative genomic studies of HCMV genome have been limited. In this study it was attempted to obtain and analyze the full genome sequence from clinical isolate from Korea. The strain JHC was isolated from Korean patient undergoing bone marrow transplantation who exhibited resistance to ganciclovir treatment (Lee et al., 2005). The virus was plaque-purified, and the full genome sequence was determined by pyrosequencing technique. The JHC genome was found to contain 235,476 bp and 165 open reading frames (ORFs). Comparison with the full genome nucleotide sequences of 11 other HCMV strains suggest that JHC is not closely related with any other strains at genome level. As expected, JHC lacked IRL sequences found in lab-adapted AD169-varUK strain and this region was replaced by ORFs UL133-UL150 as in other clinical isolates. Two ORFs (UL1 and UL119) of the strain JHC were found to be truncated due to early stop codons, and RL6 contains an unusual start codon TTG. The strain JHC contains all the genetic information for micro RNAs known to be present in HCMV.