Equine platelet lysate exhibits bacteriostatic effects against gram-negative clinical bacterial isolates.
Authors: Parker M, Arnade H, Parker J L, Gordon J, Peroni J F
Journal: Journal of equine veterinary science
Summary
# Equine Platelet Lysate as a Potential Antimicrobial Agent Antibiotic resistance in equine pathogens demands exploration of novel therapeutic approaches, and equine platelet lysate (PL) represents a promising candidate given its documented antimicrobial properties in other species. Parker and colleagues investigated whether PL could suppress growth of clinically isolated gram-negative bacteria—specifically three Enterobacteriaceae isolates (Enterobacter cloacae complex, Escherichia hormachei, and Morganella morganii)—using in vitro growth curve and time-kill assays comparing 40% v/v PL against conventional antibiotics and phosphate-buffered saline controls. The findings were striking: PL substantially suppressed bacterial growth rates across all three isolates (reducing optical density changes by 82–93% compared to controls over 16 hours), whilst additionally demonstrating early bactericidal activity within the first hour, with log fold reductions ranging from -0.09 to -0.79 depending on the organism. These reductions proved significantly superior to standard antibiotic therapy, particularly noteworthy given that the test isolates were resistant to the comparison antibiotics (ceftiofur, gentamicin, and trimethoprim-sulfamethoxazole). For practitioners managing infections caused by antibiotic-resistant gram-negative organisms, these results suggest PL warrants further investigation as an adjunctive or alternative therapeutic option, though additional work determining optimal dosing, delivery mechanisms, and efficacy in vivo remains essential before clinical application.
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Practical Takeaways
- •Equine platelet lysate may represent a potential adjunctive or alternative therapy for antibiotic-resistant bacterial infections in horses, though clinical efficacy studies are needed before practice application
- •This in vitro evidence suggests platelet lysate's antimicrobial properties warrant further investigation for treating resistant gram-negative infections in equine practice
- •Current findings are preliminary and laboratory-based; clinical trials would be required to determine appropriate dosing, safety, and efficacy in live horses before therapeutic use
Key Findings
- •Equine platelet lysate (40% v/v) demonstrated significantly reduced bacterial growth rates compared to control and antibiotic treatments, with mOD/min values of 0.93-2.39 versus 3.96-5.84 for controls
- •Platelet lysate exhibited mild bactericidal effects within 1 hour with log fold changes of -0.09 to -0.79 compared to positive log changes in PBS and antibiotic controls
- •Platelet lysate was effective against clinical bacterial isolates that were resistant to ceftiofur, gentamicin, and trimethoprim-sulfamethoxazole antibiotics