Cytomegalovirus gB genotype and clinical features in Chinese infants with congenital infections.

Objective: To investigate cytomegalovirus (CMV) glycoprotein B (gB) genotypes and clinical features in Chinese infants with congenital infections.

Methods: Urine samples were obtained from 79 infants with human CMV infection confirmed by quantitative fluorescence polymerase chain reaction (PCR). A fragment of the gB gene was amplified by nested PCR. CMV gB genotyping was carried out by restriction fragment length polymorphism, and 24 samples of the amplified DNA fragments were verified by DNA sequencing.

Results: The levels of CMV DNA in symptomatic and asymptomatic infants were 2.95 x 10(5) and 4.5 x 10(3) copies/ml, respectively, with a significant difference (p < 0.001). In all these cases, the most prevalent genotype was gB1 (50.63%), followed by gB3 (21.52%), gB2 (17.72%), and coinfection (10.13%); gB4 was not found. Moreover, gB1 was more prevalent in infants with liver damage (22/32) than in other symptomatic infants without liver damage (8/22, p = 0.019) or asymptomatic infants (10/25, p = 0.030). The homology of CMV gB in the 24 strains amplified as compared with the sequences of prototype strains in GenBank ranged from 97.06 to 99.64%.

Conclusions: The restriction fragment length polymorphism analysis of CMV gB genotypes was definite and reliable. The gB1 genotype is the most prevalent in Chinese infants with congenital CMV disease, especially in those with liver damage, followed by genotypes gB3, gB2, and gB4.