title: Survival of Ehrlichia chaffeensis in refrigerated, ADSOL-treated RBCs.
abstract: BACKGROUND
  The purpose of this study was to investigate the persistence of viable Ehrlichia chaffeensis in ADSOL-treated RBCs stored at 4 to 6 degrees C.
  
  
  METHODS
  The continuous monocytic cell lines THP-1 and DH82 were infected with E. chaffeensis (St. Vincent isolate). Packed RBC units were inoculated in separate experiments with E. chaffeensis-infected cells as final concentrations of 8.02 x 10(4) (DH82) and 1.43 x 10(4) (THP-1) infected cells per mL. Aliquots were stored at 4 to 6 degrees C for 1 to 42 days. At selected intervals, nucleated cells from the RBC aliquots were obtained by using a ficoll-isopaque separation procedure. Uninfected DH82 cell cultures were inoculated with the harvested nucleated cells or supernatant. The cell cultures were evaluated for infection by weekly examination of Wright's (Diff-Quik) stained cytocentrifuged slides. PCR amplification was also used to test the harvested nucleated cells or supernatant for the presence of E. chaffeensis DNA.
  
  
  RESULTS
  In both types of infected cell lines, E. chaffeensis was reisolated in DH82 cells for as long as 11 days from the cellular fraction and for up to 5 days from the supernatant fraction. PCR results were positive throughout the 42-day testing period.
  
  
  CONCLUSIONS
  Cell-associated E. chaffeensis remains viable in ADSOL-treated RBCs stored at 4 to 6 degrees C for at least 11 days. These data suggest that transfusion-acquired infection is possible. Successful reisolation was achieved from the supernatant fraction, which suggests that RBC products treated with a WBC-reduction procedure may still present a risk for transfusion transmission. No correlation between PCR positivity and viability of bacteria was noted.
authors.affiliation: Viral and Rickettsial Zoonoses Branch, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
authors.forename: D B
authors.initials: DB
authors.lastname: McKechnie
authors.forename: K S
authors.initials: KS
authors.lastname: Slater
authors.forename: J E
authors.initials: JE
authors.lastname: Childs
authors.forename: R F
authors.initials: RF
authors.lastname: Massung
authors.forename: C D
authors.initials: CD
authors.lastname: Paddock
mesh_terms: D000225:Adenine / Q000494:pharmacology*; D000368:Aged; D001793:Blood Preservation; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D003080:Cold Temperature; D004269:DNA, Bacterial / Q000097:blood; D018469:Ehrlichia chaffeensis / Q000166:cytology*; D016873:Ehrlichiosis / Q000097:blood; D004912:Erythrocytes / Q000187:drug effects*; D005947:Glucose / Q000494:pharmacology*; D006801:Humans; D007700:Kinetics; D008353:Mannitol / Q000494:pharmacology*; D016133:Polymerase Chain Reaction; D012965:Sodium Chloride / Q000494:pharmacology*
chemical_list: C037839:ADSOL; D004269:DNA, Bacterial; D008353:Mannitol; D012965:Sodium Chloride; D005947:Glucose; D000225:Adenine