Antibacterial Investigation of Saharan Propolis Coating on Conventional Surgical Threads

Conventional surgical threads (CST) are often colonized with drug-resistant polymicrobial biofilms. However, such bioactive agent-incorporated CST are needed to solve this problem. The aim of this study was to develop a coating for CST consisting of the antibacterial Ethanolic Extract of Sahara Propolis (EESP) as a release topical delivery system for treating wounds, characterize the EESP and study the release profiles and antibacterial activity of EESP-CST against S. aureus and P. aeruginosa. Methods: The chemical profiles of the samples were assessed by X-ray powder diffraction (XRD), Fourier-transform infrared (FT-IR) and 1H and 13C nuclear magnetic resonance (NMR) spectroscopy. The release profiles were measured in Mueller-Hinton broth (MHB) with different time 0, 30, 45, 60, 90 min and 24 h. Antibacterial activity was carried out through the agar diffusion method in Mueller- Hinton Agar (MHA).

According to the FTIR, 1H and 13C NMR analysis, the EESP through its various peaks and the various functional groups were detected. Besides, the propolis powder showed a very low degree of crystalline material (amorphous structure) as observed by X-ray powder diffraction. Exposure to EESP-CST short-term resulted in a significant reduction in absorbance at 90 min of exposure for S. aureus in MHB. In addition, the EESP-CST has not shown any significant reduction in absorbance after on for P. aeruginosa in absorbance at 90 min. However, its antibacterial ability gradually decreases after 90 min for the two bacteria tested. In MHA the zone of inhibition assay documented a efficacy of EESP-CST against S. aureus over 24 hours. But, adherence of the colony to the surface of EESP-CST was observed for P. aeruginosa. Conclusion: These results supported that the EESP-CST was successful in inhibiting the growth of S. aureus. on short-term in a liquid culture assay. Therefore, EESP-CST as a prevention of wound infections and can be an appropriate candidate for more clinical investigations.