title: HCMV strain comparison by restriction analysis of genomic virus DNA and of a PCR-amplified DNA fragment.
abstract: BACKGROUND
  Human cytomegalovirus (HCMV) is ubiquitous and a major cause of disease in the immunocompromised which include the unborn fetus. HCMV strains are closely related and may be difficult to differentiate.
  
  
  OBJECTIVE
  To analyze new HCMV isolates and highly passaged strains by conventional restriction fragment length polymorphism (RFLP) analysis of HCMV DNA and restriction analysis (RA) of a PCR-amplified a-sequence fragment to identify epidemiological relatedness.
  
  
  METHODS
  DNA from 14 low-passaged clinical isolates and the high-passaged strains S348 and AD169 were analyzed by RFLP analysis of BamHI, PstI or HpaII digestion as well as by PCR a-sequence amplification. The laboratory results were compared according to epidemiological findings.
  
  
  RESULTS
  Of the 14 clinical isolates 13 could be distinguished from each other by RFLP analysis. Isolates from an infant and its mother had identical restriction fragment patterns. Eight of 13 clinical isolates were differentiated from each other by comparing a-sequence PCR fragments according to length and the presence of cleavage sites for 6 different restriction enzymes. The mother-infant isolates were identical by the a-sequence PCR criteria. All 14 low-passaged isolates differed from the high-passaged S384 and AD169 strains by both distinguishing approaches.
  
  
  CONCLUSIONS
  Both RFLP and PCR-amplified a-sequence fragment analysis clearly differentiated between low- and high-passaged HCMV isolates and are useful epidemiological tools for determining viral strain relatedness.
authors.affiliation: Institute of Medical Virology, Humboldt University Medical School (Charité), Schumannstr. 20/21, D-10098 Berlin, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Prösch
authors.forename: U
authors.initials: U
authors.lastname: Schrader-Bechstein
authors.forename: G
authors.initials: G
authors.lastname: Witt
authors.forename: V
authors.initials: V
authors.lastname: Kimel
authors.forename: W
authors.initials: W
authors.lastname: Teterin
authors.forename: R
authors.initials: R
authors.lastname: Czshiesnek
authors.forename: D H
authors.initials: DH
authors.lastname: Krüger