title: Bacterial growth kinetics in ACD-A apheresis platelets: comparison of plasma and PAS III storage.
abstract: BACKGROUND
  Our objective was to determine the growth kinetics of bacteria in leukoreduced apheresis platelets (LR-AP) in a platelet (PLT) additive solution (PAS; InterSol, Fenwal, Inc.) compared to LR-AP stored in plasma.
  
  
  METHODS
  Hyperconcentrated, double-dose LR-AP were collected from healthy donors with a separator (AMICUS, Fenwal, Inc.). LR-AP were evenly divided, InterSol was added to half (65% InterSol:35% plasma [PAS]), and PLTs in autologous plasma were used for a paired control (PL). Bacteria were inoculated into each LR-AP PAS/PL pair (0.5-1.6 colony-forming units [CFUs]/mL), and bacterial growth was followed for up to 7 days. Time to the end of the lag phase, doubling times, maximum concentration (conc-max), and time to maximum concentration (time-max) were estimated.
  
  
  RESULTS
  Streptococcus viridans did not grow to detectable levels in either PAS or PL units. The other bacteria had no significant overall difference in the conc-max (p = 0.47) or time-max (p = 0.7) between PL and PAS LR-AP; PL had a 0.14 hours faster doubling rate (p = 0.023); and PAS had a 4.7 hours shorter lag time (p = 0.016).
  
  
  CONCLUSIONS
  We observed that five index organisms will grow in LR-AP stored in a 35%:65% ratio of plasma to InterSol where initial bacterial concentrations are 0.5 to 1.6 CFUs/mL. The more rapid initiation of log-phase growth for bacteria within a PAS storage environment resulted in a bacterial concentration up to 4 logs higher in the PAS units compared to the plasma units at 24 hours, but with no difference in the conc-max. This may present an early bacterial detection advantage for PAS-stored PLTs.
authors.affiliation: Department of Pathology, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire 03756, USA. larry.j.dumont@hitchcock.org
authors.forename: Larry J
authors.initials: LJ
authors.lastname: Dumont
authors.forename: Tammara A
authors.initials: TA
authors.lastname: Wood
authors.forename: Molly
authors.initials: M
authors.lastname: Housman
authors.forename: Louise
authors.initials: L
authors.lastname: Herschel
authors.forename: Barbara
authors.initials: B
authors.lastname: Brantigan
authors.forename: Cheryl
authors.initials: C
authors.lastname: Heber
authors.forename: Jaime
authors.initials: J
authors.lastname: Houghton
mesh_terms: D001792:Blood Platelets / Q000382:microbiology*; D001793:Blood Preservation / Q000009:adverse effects / Q000379:methods*; D004926:Escherichia coli / Q000254:growth & development / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000097:blood; D006801:Humans; D007710:Klebsiella Infections / Q000097:blood; D041121:Klebsiella oxytoca / Q000254:growth & development / Q000302:isolation & purification; D010949:Plasma / Q000382:microbiology; D010983:Plateletpheresis; D016868:Serratia Infections / Q000097:blood; D012706:Serratia marcescens / Q000254:growth & development / Q000302:isolation & purification; D012996:Solutions; D013203:Staphylococcal Infections / Q000097:blood*; D013211:Staphylococcus aureus / Q000254:growth & development / Q000302:isolation & purification; D013212:Staphylococcus epidermidis / Q000254:growth & development* / Q000302:isolation & purification; D013290:Streptococcal Infections / Q000097:blood; D034363:Viridans Streptococci / Q000254:growth & development / Q000302:isolation & purification
chemical_list: D012996:Solutions