Background: Recently the role of platelets in the tissue regeneration, wound healing and prevention and control of infections has been reported. We aimed to assess the antimicrobial effect of human platelet concentrate against six bacteria, commonly found in wound and hospital-acquired infections.
Methods: In vitro susceptibility to samples of 10 random human platelet concentrates was determined by disc diffusion method against Staphylococcus epidermidis, Staphylococcus aureus, Micrococcus luteus, Escherichia coli, Pseudomonas aeruginosa, and Proteus vulgaris. The assay was performed in triplicate for each strain and the antibacterial activities were assessed by measuring the zones of inhibition at 20, 24 and 48 hours after incubation 
at 37 °C. 
Results: Human platelet concentrate showed antibacterial activity against Staphylococcus aureus and Staphylococcus epidermidis with the mean diameter zone of inhibition of 11.4±1.1 and 10.2±1.1 mm, respectively. Whereas, no activity was observed against Micrococcus luteus, Pseudomonas aeruginosa, Escherichia coli, and Proteus vulgaris. Also, there was no significant difference in antibacterial effect of human platelet concentrate after 20, 24, and 48 hours.
Conclusion: Human platelet concentrate which is a biocompatible and safe product could be potentially useful in wound healing and hospital-acquired infections.