Escherichia coli Sepsis From Contaminated Platelet Transfusion

Evaluation of a new generation of culture bottle using an automated bacterial culture system for detecting nine common contaminating organisms found in platelet components

“…The inoculum of 10 CFU per mL was chosen because the few studies that have attempted to quantitate the degree of bacterial contamination on the day that the contamination was suspected have deduced that the majority of contaminated platelet components had bacterial contamination of at most 10 CFU per mL and because blood inoculation experiments with final inoculation concentrations of less than 5 CFU per mL are often complicated by inconsistent growth 6‐14 . In addition, it would be anticipated that in the vast majority of contaminated platelets the concentration of bacteria on Day 2 of storage would be greater than 10 CFU per mL 15 …”

Impact on Patient Outcome Following Transfusion of Bacterially Contaminated Platelets

“…Coagulase-negative staphylococci have been involved in severe sepsis after transfusion of contaminated platelets, 12 but most cases of severe sepsis are secondary to contamination with gram-negative organisms, in which endotoxin can contribute to morbidity. 29 In our study, the only patient who received a unit of platelets contaminated with a gram-negative bacterium remained asymptomatic; however, the patient was receiving antibiotic therapy at the time of infusion. This unit could have been endogenously contaminated from the donor's inapparent bacteremia at the time of collection.…”

Prevention of transfusion of platelet components contaminated with low levels of bacteria: a comparison of bacteria culture and pathogen inactivation methods

“…The strains used were Staphylococcus aureus, Staphylococcus epidermidis (ATCC 29886) , Streptococcus agalactiae, Klebsiella pneumoniae, Escherichia coli, Clostridium perfringens , and Propionibacterium acnes (Table 1). These strains were chosen to represent a variety of the most common contaminants (Gram‐positive, Gram‐negative, aerobic, and anaerobic), “fast‐growing” 15,16 and “slow‐growing,” 15,17 or because they were reported as contaminants of PLT concentrate units associated with transfusion‐transmitted sepsis 18‐20 . C. perfringens was selected because it is a spore‐forming species and it has been shown to contaminate PLT concentrates 20 .…”