Rapid identification of bacterially contaminated platelets using reagent strips: glucose and pH analysis as markers of bacterial metabolism

• Published in: Transfusion (Philadelphia, Pa.) Pa.), 1997-03, Vol.37 (3), p.255-258
• Main Authors: Burstain, J.M., Brecher, M.E., Workman, K., Foster, M., Faber, G.H., Mair, D.
• Format: Article
• Language: English
• Subjects: Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Bacillus cereus - growth & development; Bacteremia - diagnosis; Bacteremia - etiology; Bacteria - metabolism; Bacterial Infections - urine; Biological and medical sciences; Biomarkers - analysis; Blood Platelets - microbiology; Blood. Blood and plasma substitutes. Blood products. Blood cells. Blood typing. Plasmapheresis. Apheresis; Colony Count, Microbial; Glucose - analysis; Hematology; Humans; Hydrogen-Ion Concentration; Investigative techniques, diagnostic techniques (general aspects); Klebsiella pneumoniae - growth & development; Medical sciences; Pathology. Cytology. Biochemistry. Spectrometry. Miscellaneous investigative techniques; Reagent Strips; Staphylococcus epidermidis - growth & development; Transfusion Reaction; Transfusions. Complications. Transfusion reactions. Cell and gene therapy; Urine - microbiology
• ISSN: 0041-1132; 1537-2995
• DOI: 10.1046/j.1537-2995.1997.37397240205.x

BACKGROUND: One in every 1000 units of platelets is bacterially contaminated, which puts patients at risk for transfusion‐associated sepsis and death. However, there is currently no screening test in place to detect contaminated units. The use of commercially available multiple‐reagent urine dipsticks for this purpose was evaluated. STUDY DESIGN AND METHODS: Platelet concentrates were inoculated with either sterile saline or suspensions of Staphylococcus aureus, Staphylococcus epidermidis, Bacillus cereus, Klebsiella pneumoniae, or Serratia marcescens to a final concentration of 50 colony‐forming units (CFU) per mL. The platelets were analyzed daily by the use of multiple‐reagent strips, quantitative culture, and glucometry. RESULTS: B. cereus grew rapidly, reaching 107 CFU per mL 1 day after inoculation, while S. epidermidis grew slowly, achieving similar concentrations 4 to 6 days after inoculation. Two of 10 dipstick reagents, glucose and pH, proved useful in detecting bacteria. Both were lower in bacterially contaminated units than in controls. Glucose data obtained from automated analyzers validated the dipstick data. All organisms were detected at concentrations ≥107 CFU per mL, and S. aureus and K. pneumoniae were detected in the range of 103 to 105 CFU per mL. CONCLUSION: The multiple‐reagent test used had a sensitivity and specificity of 95 percent (≥107 CFU/mL) and 98 to 100 percent, respectively. These data indicate that urine dipsticks can be used to rapidly and inexpensively detect bacterial contamination in platelet concentrates, which potentially will reduce morbidity and mortality at minimal cost.