Effect of prodigiosin isolated from Serratia marcescens on wound infections induced by clinical isolates of bacteria in a murine model

Prodigiosin is a red bio-dye that is produced by Serratia marcescens and another bacterium. It is made up of a linear tripyrrole chemical structure and is classified as an alkaloid. Researchers paid attention to prodigiosin pigment due to its ability to exhibit a diverse range of biological actions, including antibacterial, antifungal, antimalarial, and anticancer properties. Objective: This study aims to assess the effectiveness of prodigiosin in treating superficial infections caused by antibiotic resistant bacteria. Methods: The red pigment found in bacterial biomass was identified as prodigiosin by studying its structure with UV-visible spectrophotometry and high-performance liquid chromatography (HPLC). The antibacterial activity against pathogenic bacteria was assessed in vitro using agar well diffusion method. A mouse experimental wound model was used to initiate infection by Pseudomonas aeruginosa and Staphylococcus aureus. The topical treatment was administered 4 hours after the injury and continued until the wound was fully healed. Results: The pigment exhibited a maximum absorbance peak at 535 nm. All strains that were tested showed sensitivity and produced significant areas of inhibition zones against P. aeruginosa (16.50±1.36mm) and S. aureus (20.83±2.40mm). Topical applications of prodigiosin (0.1% prodigiosin in Vaseline) have been proven to be beneficial. The scar healing was completed, with no remaining lesions and no signs of redness. The highest rate of decrease was shown at 95 mg/ml for S. aureus (C0.003±0.003b) followed by P. aeruginosa (D0.02±0.008b).  Conclusion: Prodigiosin, showed great potential as a natural substitute for synthetic drugs due to its potent antimicrobial properties against superficial skin infections caused by bacteria.