EVALUATION OF ANTI-MICROBIAL ACTIVITY AND WOUND HEALING OF KEFIR

Objective: Pseudomonas aeruginosa has emerged as an important cause of serious wound infection and death in burn patients. There are a limited numbers of antimicrobial agents affecting the bacterium due to its inherent resistance. Kefir is a natural probiotic which contains diverse spectrum of bacteria, yeasts and their metabolites with potential antimicrobial activity. Current study was designed to investigate the antimicrobial activity of Kefir extract against P. aeruginosa (ATCC 27853) as well as burn clinical isolates. Materials and Methods: In this descriptive study, the Kefir fermented in MRS Broth medium for 24 hours (hrs), 48 hrs and 96 hrs and their extract were used for evaluation of antibacterial effect. The antibacterial effect of different kefir extract were compared based on measurement of diameter of inhibition zone in diffusion plate method, and assessment of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The density of bacteria and percentage of organic acids (lactic and acetic acids) were also tested. Kefir gels were prepared by mixing of equal portions of gel base and 96 hours supernatant of kefir grain cultivated in MRS Broth medium. Antibacterial effects of kefir grain supernantants taken at 24, 48, 72 and 96 hours times intervals were evaluated. Burn injuries were created on dorsal skin surface of 32 rats. After 24 h wounds were infected with Pseudomonas aeruginosa. The infected rats were divided in to 4 groups of 8 rats each. Burn wounds area were measured before treatment as well as one and two weeks after. Animals in all groups were sacrificed and whole skin wound areas were removed and the percentages of epithelization, scar formation, inflammation and angiogenesis were assessed. Results: After two weeks treatment the 96 h kefir gel showed lower percentage of inflammation and also better epithelization compared to silver sulfadiazine 1%, base gel and untreated groups. Conclusion: Kefir extract showed a promising anti-pseudomonal effect and was able to significantly improve wound healing. However further experiments and clinical trials needs to be conducted before it could be used in human.