Fatal false‐negative transfusion infection involving a buffy coat platelet pool contaminated with biofilm‐positive Staphylococcus epidermidis: a case report. Issue 10 (18th May 2015)

• Record Type: Journal Article
• Authors: Kou, Yuntong; Pagotto, Franco; Hannach, Barbara; Ramirez‐Arcos, Sandra
• Is Part Of: Transfusion. Volume 55:Issue 10(2015)
• Page Start: 2384
• Page End: 2389
• Publication Date: 2015-05-18
• Subjects: Hematology -- Periodicals; Blood -- Transfusion -- Periodicals; Blood Group Antigens -- Periodicals; Blood Preservation -- Periodicals; Blood Transfusion -- Periodicals; 615
• DOI: 10.1111/trf.13154
• Languages: English
• ISSNs: 0041-1132

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="trf13154-sec-0001" sec-type="section"> <title>BACKGROUND</title> <p>Bacterial contamination of platelet concentrates (PCs) poses the major posttransfusion infectious risk in developed countries. The aerobic microorganism most frequently isolated from PCs is coagulase‐negative <italic>Staphylococcus epidermidis</italic>, a normal inhabitant of the human skin, which has been involved in fatal transfusion reactions worldwide.</p> </sec> <sec id="trf13154-sec-0002" sec-type="section"> <title>CASE REPORT</title> <p>In September 2014, a splenectomized elderly male patient, suffering from leukemia, was transfused with two 5‐day‐old buffy coat platelet (PLT) pools. The patient returned to emergency on the same day with a low‐grade fever. He was bacteremic and died on the next day. Microbiology and molecular testing of a blood sample from the patient and one of the PCs yielded the same <italic>S. epidermidis</italic> strain. Further analysis demonstrated that this <italic>S. epidermidis</italic> isolate displays a biofilm‐positive phenotype in PCs.</p> </sec> <sec id="trf13154-sec-0003" sec-type="section"> <title>DISCUSSION</title> <p>At Canadian Blood Services, PCs are screened for bacterial contamination with the BacT/ALERT system (bioMérieux) at approximately 24 hours postcollection. The implicated PC had been tested and yielded a false‐negative culture result. A titration experiment indicated that, at the time of screening, the contaminated PC had a titer of less than 0.74 colony‐forming units (CFU)/mL (<227 CFUs/unit) of <italic>S. epidermidis</italic>. Mathematical models have predicted that up to 70% of PCs contaminated with coagulase‐negative staphylococci at concentrations of 0.02 CFU/mL can be missed by BacT/ALERT screening.</p> </sec> <sec id="trf13154-sec-0004" sec-type="section"> <title>CONCLUSION</title> <p>Despite several mitigation strategies, false‐negative cultures with current PLT screening practices still occur. This report creates awareness of the pathogenicity of opportunistic <italic>S. epidermidis</italic>, a low‐virulence organism, in susceptible patients who may not develop a typical transfusion reaction.</p> </sec> </abstract>