Antibiotic-labeled probes and microvolume fluorimetry for the rapid detection of bacterial contamination in platelet components: a preliminary report.
BACKGROUND
Approximately 1 platelet in 2000 components is bacterially contaminated. Most commonly, contaminating organisms are gram positive skin saprophytes (such as Staphylococcus sp. or Bacillus sp.). A novel approach to the rapid diagnosis of gram positive contamination by the use of a fluorescence-labeled antibiotic probe with affinity for the gram positive cell was investigated.


METHODS
Two isolates of Staphylococcus epidermidis were inoculated into bags of Day 0 platelets. Quantitative cultures along with a semi-automated screening assay on a microvolume fluorimeter employing a fluorescence-conjugated vancomycin probe was performed for each day of storage. In addition, serial dilutions of the bacteria were added to sterile platelets to achieve a range spanning 10(1) to 10(8) CFUs per mL.


RESULTS
All samples with a bacterial contamination of > or =10(5) CFU per mL were detected. Sterile samples were nonreactive. The entire procedure requires three pipetting steps and took less than 1 hour to perform.


CONCLUSIONS
These preliminary results with the use of fluorescence-labeled antibiotics as probes combined with microvolume fluorimetry for the rapid detection of bacterial contamination of platelet components suggest that this is a promising approach. Further studies with additional organisms and alternative conjugates, bacteria, and antibiotics are underway.
Brecher
M E
ME
University of North Carolina Hospitals, Chapel Hill, NC 27514, USA. Brechergmed@unc.edu
Wong
E C
EC
Chen
S E
SE
Vampola
C
C
Rocco
R M
RM
D000900:Anti-Bacterial Agents / Q000097:blood*; D001407:Bacillus / Q000302:isolation & purification; D001424:Bacterial Infections / Q000635:transmission; D001792:Blood Platelets / Q000382:microbiology*; D005456:Fluorescent Dyes / Q000032:analysis*; D005470:Fluorometry / Q000379:methods; D006801:Humans; D013210:Staphylococcus / Q000302:isolation & purification; D065227:Transfusion Reaction; D014640:Vancomycin / Q000097:blood*
D000900:Anti-Bacterial Agents; D005456:Fluorescent Dyes; D014640:Vancomycin