34th Annual Scientific Meeting proceedings

Objectives:

In addition to facilitating haemostasis, platelets show wound-healing and antimicrobial properties. The factors affecting the effectiveness of platelet products may include the manufacturing process, platelet concentration, leukocyte content, platelet activation, and pooling of individual donors.

Methods:

Blood was collected from six dogs. Leukocyte-rich and leukocyte-reduced platelet-rich plasma was produced using centrifugation methods. Platelet lysate (PL) was generated through freeze-thaw cycles. A portion of samples underwent plasma depletion and/or heat treatment. Treatment groups were tested against bacterial strains by a bacteria spiking assay at 3 and 24 h and a 24-h growth curve assay with 20% and 80% treatment concentrations, which included samples with oxacillin or amikacin.

Results:

The log reduction of Staphylococcus aureus and Escherichia coli after 3 h was greater with PL than with broth (P = 0.0027 and P = 0.0486). Plasma depletion led to weaker log reduction of Staphylococcus pseudintermedius (P = 0.0478) and improved log reduction of Enterococcus faecalis (P = 0.0396) after 3 h. Heat treatment led to a weaker log reduction of Enterococcus faecalis after 24 h (P = 0.0026). Leukocyte concentration made no difference. PL suppressed the growth of Staphylococcus aureus best at 20% and Staphylococcus pseudintermedius best at 80%. PL appeared to show synergistic effects with amikacin against Staphylococcus aureus, but the effectiveness of oxacillin decreased.

Conclusions:

PL has antimicrobial effects. For the most efficacious product, the manufacturing, dose, and plasma content may need to be tailored to the targeted bacteria. PL showed synergism with amikacin but not with oxacillin. Further research is warranted to evaluate the optimal use of PL as an antimicrobial.