Abstract: Objectives To investigate the antibacterial effects of platelet lysate (PL) in vitro and its synergistic effect with antibiotics. Methods Escherichia coli (E. coli) and K. pneumoniae were selected for PL in vitro antibacterial experiment by microplate method and Oxford cup drilling method. Gentamicin (GM), platelet rich plasma (PRP) positive control and platelet poor plasma (PPP) negative control was set in microplate method, OD value was determined, and antibacterial rate was calculated. The diameter of the antibacterial circle was determined by Oxford cup drilling method. Results The antibacterial rate against E. coli was found to be GM>PL>PRP>PPP (P<0.05), and the inhibition rate gradually decreased with the decrease of PL concentration; The antibacterial rate of PL on E. coli reached its peak at 4 hours, and gradually decreased with the prolongation of time. The combination of PL and GM enhanced the antibacterial effect of GM, with PL+GM zone of inhibition greater than GM zone of inhibition. The antibacterial effect against K. pneumoniae was found to be GM+PL>GM>PL. Conclusion PL has a certain antibacterial effect, but weaker than antibiotics. Its antibacterial effect gradually weakens with the prolongation of time and the decrease of concentration, and has a synergistic antibacterial effect.

Key words: Platelet-rich plasma, Platelet lysate, Antibacterial experiment, Antibacterial rate