Does the PRP of those with diabetes have antimicrobial properties?

This study aimed to determine the inherent antibacterial properties of autologous PRP from 40 study participants. The participants consisted of 3 groups. Healthy diabetics and healthy age, gender matched(n=13) and a discreet group of 14 participants with a non-healing DFU . Ethical approval was obtained from ORECNI (10/NIRO2/30).
A sample of 24ml of whole venous blood was drawn from each participant and prepared as per the manufacturer’s instructions to produce PRP.
The antibacterial efficacy of PRP was established using the well diffusion assay. Five wells were aseptically created in each nutrient agar plate seeded with lawns of S. aureus (NCTC 8329), Ps. aeruginosa (NCTC 10780), Methicillin resistant S. aureus (MRSA) (NCTC 8323), MRSA - clinical isolate, S. pyogenes (β Haemolytic Streptococcus) (NCTC10876), Proteus vulgaris (NCTC10031) and E. coli (NCTC09001). These bacteria are of significance in diabetic foot wounds 1,2 . PRP from the study participants was aseptically transferred into 4 of the wells; the 5th (control) well contained Ringers solution. The plates were incubated at 37 °C for 24 hours, and the resultant zones of inhibition were used to provide a semi-quantitative estimation of antibacterial activity.
Results
Zones of inhibition (ZOI) were observed on the lawns of S.aureus, S. pyogenes, and Proteus vulgaris, of all participants. ZOI were also observed on the lawns of MRSA (both types) in the age gender matched group and participants with an active diabetic foot wound.
Enhanced growth of Ps. aeruginosa was observed in the healthy participants (n=11), as previously found by Bielecki et al. 3 (2007), but was also observed in participants with diabetes and participants with diabetes (n=10) and an active diabetic foot wound (n=13).
Discussion
These findings demonstrate that PRP has a wider than previously recognised range of antimicrobial activity against infecting/contaminating bacteria. Zones of inhibition were not identified for all the participants on the plates with lawns of these organisms.
The lack of antimicrobial properties against Ps. aeruginosa is important as it causes 9.3% to 31% of diabetic foot infections 3 is known to form biofilms, and has been linked to the migration of keratinocytes.

1.Lipsky, B., Berendt, A. 2000. Principles and practice of antibiotic therapy of diabetic foot infections. Diabetes / Metabolism Research and Reviews, 16 (Suppl), 42-46.
2. Vardakas, K., Horianopoulou, M., Falagas, M. 2008. Factors associated with treatment failure in patients with diabetic foot infections: An analysis of data from randomized controlled trials. Diabetes Research and Clinical Practice, 80 (3), 344-351.
3 Bielecki, T., Gazdzik, T., Arendt, J., Szczepanski, T., Król, W. and Wielkoszynski, T. 2007. Antibacterial effect of autologous platelet gel enriched with growth factors and other active substances: an in vitro study. Journal of Bone and Joint Surgery (British volume), 89 (3), 417-420.

4 Viswanathan V. 2007 The diabetic foot: perspectives from Chennai, South India. International Journal of Lower Extremity Wounds. 6(1):34-6.
5 Swarna, S., Madhavan, R., Gomathi, S., Thamaraiselvi, D., Thamaraiselvi, S. 2012. A study of Biofilm on Diabetic Foot Ulcer. International Journal of Research in Pharmaceutical and Biomedical Sciences, 3 (4), 1809-1814.