Rapid epidemiologic characterization of cytomegalovirus strains from pediatric bone marrow transplant patients.

BACKGROUND: DNA amplification by the polymerase chain reaction (PCR) of human cytomegalovirus (CMV) nucleotide sequences recently has been reported for differentiation of CMV strains.
DESIGN: Retrospective study. OBJECTIVE AND PATIENTS: Evaluate the strain patterns of 15 CMV-positive buffy coat specimens from five pediatric bone marrow transplant patients.
SETTING: Pediatric bone marrow transplant unit.
METHODS: We perform PCR using primers corresponding to two distinct regions of the CMV genome, the major immediate-early (MIE) region and the a-sequence region, with subsequent restriction enzyme analysis of the amplified products.
RESULTS: Restriction enzyme analysis with Hae III and Hinf I of products amplified with nested PCR for the MIE region revealed distinguishable digestion patterns between patients but similar patterns for samples from each patient. All were distinct from the CMV Towne laboratory control strain. In contrast to these results, amplification of specimens with a-sequence primers, followed by restriction enzyme analysis, did not allow differentiation between all patients.
CONCLUSION: Our results indicate that nested amplification directly from buffy coat specimens using primers for the CMV MIE gene allows rapid CMV strain characterization that is useful for laboratory quality control and epidemiological studies. Distinct CMV strains were found in each patient, suggesting horizontal transmission was not responsible for acquisition of CMV infection in these patients.