Identification of a 1.6 kb genome locus of guinea pig cytomegalovirus required for efficient viral growth in animals but not in cell culture

AbstractGuinea pig cytomegalovirus (GPCMV) provides a useful model for studies of congenital CMV infection. During characterization of the GPCMV genome sequence, we identified two types of strains in a virus stock purchased from ATCC. One of them, GPCMV/del, lacks a 1.6 kb locus that positionally corresponds to murine CMV (MCMV) M129–M133. Growth of GPCMV/del in cell culture was marginally better than that of the other strain, GPCMV/full, which harbors the 1.6 kb locus. However, in animals infected intraperitoneally with virus stocks containing both strains, GPCMV/full disseminated more efficiently than GPCMV/del, including 200-fold greater viral load in salivary glands. Viral DNA, transcripts of the immediate-early 2 gene homolog, and viral antigens were more abundant in animals infected with GPCMV/full than in those infected with GPCMV/del. Although the observed phenomena have some similarity with the growth properties of MCMV strains defective in mck-1/mck-2(M129/131) and those defective in sgg(M132), no M129–M132 homologs were found in the 1.6 kb locus. Since one of the ORFs in the locus has a weak sequence similarity with HCMV UL130, which relates to cell tropism, further studies will be required to learn the mechanism for efficient GPCMV growth in animal

Real-Time PCR Assay Using Specimens on Filter Disks as a Template for Detection of Cytomegalovirus in Urine

Since congenital cytomegalovirus (CMV) infection causes late-onset sequelae, the identification of CMV-infected newborns is important. For this purpose, we established a simple real-time PCR assay using a filter disk. Combined with the collection of urine using filter papers placed in the diaper, this assay can make CMV screening more feasible and cost-effective