title: Septic transfusion case caused by a platelet pool with visible clotting due to contamination with Staphylococcus aureus.
abstract: BACKGROUND
  Contamination of platelet concentrates (PCs) with Staphylococcus aureus is one of the most significant ongoing transfusion safety risks in developed countries.
  
  
  METHODS
  This report describes a transfusion reaction in an elderly patient diagnosed with acute myeloid leukemia, transfused with a 4-day-old buffy coat PC through a central venous catheter. The transfusion was interrupted when a large fibrous clot in the PC obstructed infusion pump flow. Shortly afterward, a red blood cell (RBC) unit transfusion started. After septic symptoms were developed, the RBC transfusion was also interrupted. While the RBC unit tested negative for bacterial contamination, the PC and the patient samples were found to be contaminated with a S. aureus strain that exhibited the same phenotypic and genome sequencing profiles. The isolated S. aureus forms biofilms and produces the superantigen enterotoxin-like U, which was detected in a sample of the transfused PCs. The patient received posttransfusion antibiotic treatment and had her original central line removed and replaced.
  
  
  CONCLUSIONS
  As the implicated PC had been tested for bacterial contamination during routine screening yielding negative results, this is a false-negative transfusion sepsis case. Using a point-of-care test could have prevented the transfusion reaction. This report highlights the increasing incidence of S. aureus as a major PC contaminant with grave clinical implications. Importantly, S. aureus is able to interact with platelet components resulting in visible changes in PCs.
  
  
  CONCLUSIONS
  Visual inspection of blood components before transfusion is an essential safety practice to interdict the transfusion of bacterially contaminated units.
authors.affiliation: Canadian Blood Services.
authors.forename: Maria
authors.initials: M
authors.lastname: Loza-Correa
authors.affiliation: Canadian Blood Services.
authors.forename: Yuntong
authors.initials: Y
authors.lastname: Kou
authors.affiliation: Canadian Blood Services.
authors.forename: Mariam
authors.initials: M
authors.lastname: Taha
authors.affiliation: Agriculture and Agri-Food Canada.
authors.forename: Miloslav
authors.initials: M
authors.lastname: Kalab
authors.affiliation: Health Canada, Ottawa, Ontario, Canada.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Ronholm
authors.affiliation: Department of Microbiology, Carver College of Medicine, Iowa City, Iowa.
authors.forename: Patrick M
authors.initials: PM
authors.lastname: Schlievert
authors.affiliation: Department of Microbiology, Carver College of Medicine, Iowa City, Iowa.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Cahill
authors.affiliation: Department of Microbiology, Carver College of Medicine, Iowa City, Iowa.
authors.forename: Robert
authors.initials: R
authors.lastname: Skeate
authors.affiliation: University Health Network, Toronto, Ontario, Canada.
authors.forename: Christine
authors.initials: C
authors.lastname: Cserti-Gazdewich
authors.affiliation: Canadian Blood Services.
authors.forename: Sandra
authors.initials: S
authors.lastname: Ramirez-Arcos
mesh_terms: D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D062905:Central Venous Catheters / Q000382:microbiology; D017707:Erythrocyte Transfusion / Q000009:adverse effects; D005260:Female; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000628:therapy; D017713:Platelet Transfusion / Q000009:adverse effects*; D018805:Sepsis / Q000209:etiology*; D013203:Staphylococcal Infections / Q000635:transmission*; D013211:Staphylococcus aureus; D065227:Transfusion Reaction / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents