The antimicrobial and antifungal effects of Keffir in vitro

Abstract

Objective: Keffir is known as one of the sour milk products originated in the north of Caucasus. The antimicrobial and antifungal effects of this product has not already been investigated. In general, keffir contains the following microorganisms: Lactic acid streptococci, lactobacilli, mesophilic lactic acid, lactose fermenting and non-fermenting yeasts and lactic acid bacteria. The objective of this study was to determine therapeutic effects of keffir. Methods: This study was performed on bacteria such as staphylococcus aureus, E.coli, pseudomonas aeruginosa, salmonella typhi, and three species of fungi: Candida albicans, trichophyton mentagrophytes and microsporum canis. The antimicrobial effects of eight extracts of common yogurt and extract of keffir at 20°C and 37°C at two times of 24 and 48 hour fermentation in vitro on four species of bacteria and three species of fungi were studied by cup plate and serial dilution methods. Findings: From extract of common and keffir yogurt at 20°C and 37°C at two times of 24 and 48 hour fermentation, keffir with 75 mg/ml concentration showed the strongest effect on P.aeruginosa at 37°C with 48 hour fermentation time. Conclusion: keffir has an antimicrobial effect on some pathogenic bacteria as P.aeruginosa.

Keywords

• antimicrobial effects
• common yoghurt
• keffir yoghurt
• pathogenic bacteria
• fungi