Detection of CMV in urine: comparison between DNA-DNA hybridization, virus isolation, and immunoelectron microscopy

Rapid detection of CMV-DNA in urine specimens by dot-blot hybridization was compared to conventional virus isolation and to virus identification using solid-phase immunoelectron microscopy (SPIEM). To detect viral DNA, 32P-labeled EcoR1 J fragment of CMV-DNA was used as a probe in the hybridization assay. In addition, DNA extracted from infected human embryo fibroblasts (amplified DNA) was also hybridized to the same probe. Urine specimens were obtained from 10 renal transplanted patients, seven premature infants, three family members, and five children suspected of CMV infection. CMV was isolated from 10 urine specimens and SPIEM detected viral particles in nine specimens. Ten positive samples were identified as such by hybridization with DNA extracted directly from urine specimens, while hybridization with amplified DNA yielded 17 positives. Only in one urine specimen, positive by virus isolation and SPIEM, DNA was not detected by the hybridization assays. Elevated IgG or IgM-specific antibodies were found in 10 patients. Hybridization with amplified DNA proved the most sensitive and relatively rapid assay, as compared with direct DNA detection in urine, tissue culture isolation, SPIEM, or serologic tests.