Table 9.
Antibacterial activity of kefir against E. coli, S. Typhimurium, and S. aureus.
| Type of kefir | CFS conc. | E. coli (CFU mL−1)∗ | S. Typhimurium (CFU mL−1)∗ | S. aureus (CFU mL−1)∗ |
|---|---|---|---|---|
| Fermented cow's milk (cow's milk kefir) | 100% CFS | NG (−) | NG (−) | NG (−) |
| 75% CFS | NG (−) | NG (−) | NG (−) | |
| 50% CFS | NG (−) | NG (−) | NG (−) | |
| 25% CFS | NG (−) | NG (−) | NG (2.0 × 103) | |
| Unfermented CFS | G (>1.5 × 105) | G (>1.5 × 105) | G (>1.5 × 105) | |
|
| ||||
| Fermented soy milk (soy milk kefir) | 100% CFS | NG (−) | NG (−) | NG (−) |
| 75% CFS | NG (−) | NG (−) | NG (4.0 × 102) | |
| 50% CFS | NG (−) | NG (−) | NG (6.7 × 103) | |
| 25% CFS | NG (−) | NG (−) | G (5.3 × 104) | |
| Unfermented CFS | G (>1.5 × 105) | G (>1.5 × 105) | G (>1.5 × 105) | |
|
| ||||
| Nutrient broth | G (>1.5 × 105) | G (>1.5 × 105) | G (>1.5 × 105) | |
∗CFSs were inoculated with 3.5 × 105 CFU of E. coli, 3.1 × 105 CFU of S. Typhimurium, and 2.0 × 105 CFU of S. aureus. G/NG: growth or no growth observed by turbidity. Samples were taken, inoculated, and enumerated in nutrient agar. Viable counts in nutrient agar are shown in parentheses. CFS was considered as bactericidal when no viable counts were observed.