Table 3. Changes in bacterial count at 24 hr post-incubation with cefazolin (CEZ) and nisin A, alone and in combination.
| Organism | × MIC | Changes in bacterial count (log10 CFU/ml) from 0 hr |
a − c | b − c | Interpretation | ||
|---|---|---|---|---|---|---|---|
| CEZ (a) | Nisin A (b) | CEZ-nisin A (c) | |||||
| Staphylococcus aureus | 1 | 0.10 | 1.64 | –3.29 | 3.39 | 4.93 | S |
| Staphylococcus intermedius | 0.5 | 2.26 | 2.68 | –3.17 | 5.43 | 5.85 | S |
| Streptococcus agalactiae | 1 | 0.50 | 1.69 | –3.31 | 3.81 | 5.00 | S |
| Streptococcus dysgalactiae | 0.5 | 2.14 | 3.08 | –3.10 | 5.24 | 6.18 | S |
| Enterococcus faecalis | 0.5 | 1.72 | 2.67 | –3.36 | 5.08 | 6.03 | S |
| Escherichia coli | 0.5 | 2.31 | 2.45 | –3.16 | 5.47 | 5.61 | S |
Bacterial count was measured by the change in log10 CFU/ml from 0 to 24 hr post-incubation, obtained from the data in Fig. 1. (i.e., log change = log10 CFU24 ‒ log10 CFU0). The results are calculated at 0.5 × MIC, except in the case of S. aureus and S. agalactiae (1 × MIC). S, synergism.