Human cytomegalovirus strains associated with congenital and perinatal infections

The genotypes of human cytomegalovirus (HCMV) isolates from pediatric patients differs from those of infected adults in Australia. Genotypes were determined by PCR amplification of glycoprotein B (gB) sequences, with subsequent analysis by restriction fragment length polymorphism, single‐stranded conformation polymorphism, heteroduplex mobility analysis and direct DNA sequencing. Restriction fragment length polymorphism analysis of gB showed genotypes gB1 (39%) and gB3 (30%) were more prevalent in infected children and two new genotypes (gB6 and gB7) were found. Single‐stranded conformation polymorphism was used to group isolates into 22 further subtypes and suggested longitudinal co‐infection or viral mutation was occurring over time. Heteroduplex mobility analysis was found to be the most accurate and concise of the four methods used for genotyping HCMV isolates. DNA sequencing was used to confirm the results obtained from heteroduplex mobility analysis, and identified two isolates that were incorrectly genotyped by restriction fragment length polymorphism analysis. Heteroduplex mobility analysis efficiently genotyped all samples and allowed estimation of sequence variation between isolates. These data suggest certain gB genotypes are associated more commonly with childhood infections, and these differ from strains associated with invasive disease in HIV patients. J. Med. Virol. 61:481–487, 2000. © 2000 Wiley‐Liss, Inc.