Related Experiment Video
Updated: Aug 21, 2026
Aseptic Laboratory Techniques: Plating Methods
Published on: May 11, 2012
Growth of gram-positive and gram-negative bacteria in platelet concentrates
A Punsalang1, J M Heal, P J Murphy
1American Red Cross Blood Services, Rochester, New York.
Abstract:
In 1986 the allowable platelet storage time was reduced from 7 to 5 days because of a recent increase in septic deaths associated with platelet transfusion. In this study, the growth curves of two gram-positive and two gram-negative organisms in platelets stored for 7 days in CLX and PL-732 bags were evaluated. Platelets in CLX bags were inoculated with 10(1), 10(2), and 10(3) organisms and 10(2) organisms were introduced into PL-732 bags. Test organisms were inoculated into trypticase soy broth as a control. All four bacteria grew rapidly in trypticase soy broth, reaching 10(9) organisms per mL within 48 hours. In both CLX and PL-732 bags, the growth pattern of gram-positive organisms was generally logarithmic during the first few days of storage. A concentration of 10(8) organisms per mL was present by Day 3 or 4, after which further proliferation was inhibited by the high density of bacteria in the platelets. In PL-732 bags, the proliferation of gram-negative organisms followed a pattern similar to that of the gram-positive bacteria. However, gram-negative organisms grew less well in CLX bags.(ABSTRACT TRUNCATED AT 250 WORDS)
Insights
Bacterial growth in stored platelets was studied to understand risks. Gram-positive bacteria grew logarithmically in both storage bags, while gram-negative bacteria grew less effectively in CLX bags.
Area of Science:
- Microbiology
- Transfusion Medicine
- Biotechnology
Background:
- Platelet storage time was shortened due to increased septic deaths from transfusions.
- Understanding bacterial proliferation in stored platelets is critical for transfusion safety.
Observation:
- Bacterial growth curves were evaluated for gram-positive and gram-negative organisms in platelets stored in CLX and PL-732 bags.
- Organisms were inoculated at varying concentrations (10^1 to 10^3) into platelet bags and trypticase soy broth controls.
Findings:
- All tested bacteria grew rapidly in trypticase soy broth, reaching 10^9 organisms/mL within 48 hours.
- Gram-positive bacteria exhibited logarithmic growth in both CLX and PL-732 bags, reaching 10^8 organisms/mL by days 3-4.
- Gram-negative bacteria showed similar proliferation in PL-732 bags but grew less effectively in CLX bags.
Implications:
- Bacterial contamination in platelet products poses a significant risk.
- Storage bag type influences bacterial growth dynamics, impacting transfusion safety.
- Further research is needed to optimize platelet storage and minimize transfusion-associated sepsis.
