Abstract
The development of antimicrobial resistant bacteria and the lack of novel antibiotic strategies to combat those bacteria is an ever-present problem in both veterinary and human medicine. The goal of this study is to evaluate platelet lysate (PL) as a biological alternative antimicrobial product. Platelet lysate is an acellular platelet-derived product rich in growth factors and cytokines that is manufactured via plateletpheresis and pooled from donor horses. In the current study, we sought to define the antimicrobial properties of PL on select gram-positive and gram-negative bacteria. Results from an end-point in vitro assay showed that PL did not support bacterial growth, and in fact significantly reduced bacterial content compared to normal growth media. An in vitro assay was then utilized to further determine the effects on bacterial growth dynamics and showed that all strains exhibited a slower growth rate and lower yield in the presence of PL. The specific effects of PL were unique for each bacterial strain: E. coli and P. aeruginosa growth was affected in a concentration-dependent manner, such that higher amounts of PL had a greater effect, while this was not true for S. aureus or E. faecalis. Furthermore, the onset of exponential growth was delayed for E. coli and P. aeruginosa in the presence of PL, which has significant clinical implications for developing a dosing schedule. In conclusion, our findings demonstrate the potential value of PL as a broad-spectrum antimicrobial that would offer an alternative to traditional antibiotics for the treatment of bacterial infection in equine species.
Highlights
Biological products derived from platelets have been extensively studied as potential therapies because they are a rich source of bioactive elements including growth factors, which are thought to promote healing of injured tissues [1,2,3,4,5]
A preliminary end-point in vitro assay designed to expose S. aureus, E. coli, P. aeruginosa and E. faecalis to 100% platelet lysate (PL), showed that bacterial content was significantly reduced in the presence of PL compared to control BHI growth media (Figure 1A)
We were concerned that PL as a blood-derived product rich in growth factors and other bioactive serum proteins would support rather than inhibit bacterial growth [17]
Summary
Biological products derived from platelets have been extensively studied as potential therapies because they are a rich source of bioactive elements including growth factors, which are thought to promote healing of injured tissues [1,2,3,4,5]. Once platelets are collected and concentrated, several techniques can be employed to promote the release of these growth and chemotactic factors present in their alpha granules. These factors are captured in what is known as a platelet releasate or platelet lysate (PL), which can be further refined in the lab to remove cellular debris resulting in an acellular product. PL is manufactured in the laboratory and pooled from a minimum of three donors to be stored until required. We have shown that pooled PL is more effective at suppressing cell-mediated inflammation than PL obtained from individual horses [6], possibly because it contains a more consistent balance of effector proteins
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
