title: Detection of bacteria in WBC-reduced PLT concentrates using percent oxygen as a marker for bacteria growth.
abstract: BACKGROUND
  The risk of receiving a PLT concentrate (PC) contaminated with bacteria may be 1000-fold greater than that of pathogenic viral transmission, yet surveillance for this risk is not generally practiced. A novel bacteria detection system (BDS) that overcomes the limitations of current systems is described. The BDS monitors percent oxygen (%O2) in air above aliquots of PCs that have been filtered to remove the confounding effect of respiring PLTs and residual WBCs.
  
  
  METHODS
  One-day-old WBC-reduced whole-blood-derived PCs (WBPCs) were inoculated with bacteria at 100 to 500 CFU per mL. After 30 minutes, 2- to 3-mL aliquots were processed through a PLT-reducing filter into a sample pouch containing sodium polyanethol sulfonate and entrained air. After incubation at 35 degrees C for at least 24 hours, the %O2 was measured within the pouch. Noninoculated WBC-reduced WBPCs (n = 155), confirmed free of bacteria by routine culture, were tested in a like manner. Results from the latter group of WBC-reduced WBPCs were used to distinguish contaminated from noncontaminated units.
  
  
  RESULTS
  After a 24-hour incubation at 35 degrees C, 195 (96.5%) of the 202 sample pouches obtained from inoculated units were detected by the BDS. After an additional 6 hours at room temperature, those that remained and were tested were found positive. None of the noninoculated controls produced a positive reading.
  
  
  CONCLUSIONS
  The BDS is easy to use and provides good levels of sensitivity and specificity.
authors.affiliation: Pall Corporation, Scientific and Laboratory Services, Research and Development, East Hills, New York, USA. jerry_ortolano@pall.com
authors.forename: Girolamo A
authors.initials: GA
authors.lastname: Ortolano
authors.forename: Lawrence F
authors.initials: LF
authors.lastname: Freundlich
authors.forename: Stein
authors.initials: S
authors.lastname: Holme
authors.forename: Rosalind L
authors.initials: RL
authors.lastname: Russell
authors.forename: Mary Anne
authors.initials: MA
authors.lastname: Cortus
authors.forename: Karen
authors.initials: K
authors.lastname: Wilkins
authors.forename: Hiromi
authors.initials: H
authors.lastname: Nomura
authors.forename: Chiyong
authors.initials: C
authors.lastname: Chong
authors.forename: Raleigh
authors.initials: R
authors.lastname: Carmen
authors.forename: Anthony
authors.initials: A
authors.lastname: Capetandes
authors.forename: Barry
authors.initials: B
authors.lastname: Wenz
mesh_terms: D001419:Bacteria / Q000254:growth & development / Q000302:isolation & purification*; D001424:Bacterial Infections / Q000175:diagnosis / Q000517:prevention & control* / Q000635:transmission; D001431:Bacteriological Techniques / Q000295:instrumentation / Q000379:methods*; D015415:Biomarkers; D001792:Blood Platelets / Q000382:microbiology*; D006801:Humans; D007962:Leukocytes / Q000166:cytology*; D010100:Oxygen / Q000032:analysis*; D017713:Platelet Transfusion; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; D010100:Oxygen