Table 1.
Minimum Inhibitory Concentration and Minimum Bactericidal Concentration of P. vera L. ORS and LVX against H. pylori strains at two pH values and the effect of the combination of P. vera L. ORS and LVX determined by the checkerboard test and calculation of the Fractional Inhibitory Concentration Index (FIC I)
| H. pylori strains | P. vera L. ORS (mg/l) | LVX (mg/l) | Best combination ORS + LVX (mg/l)# | FIC I* | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| MIC | MBC | MIC | MBC | |||||||
| pH | pH | pH | pH | |||||||
| 7.0 | 5.5 | 7.0 | 5.5 | 7.0 | 5.5 | 7.0 | 5.5 | |||
| 11F/11 | 1560 | 1560 | 1560 | 3120 | 1.00 | 1.00 | 1.00 | 1.00 | 90 + 0.12 | 0.18 |
| 2A/12 | 1560 | 3120 | 3120 | 6250 | 0.50 | 1.00 | 0.50 | 1.00 | 190 + 0.12 | 0.36 |
| 3F/12 | 1560 | 1560 | 3120 | 3120 | 1.00 | 1.00 | 1.00 | 1.00 | 390 + 0.12 | 0.37 |
| 4A/12 | 1560 | 3120 | 1560 | 3120 | 0.50 | 0.50 | 0.50 | 0.50 | 390 + 0.12 | 0.49 |
| 7A/12 | 1560 | 1560 | 3120 | 3120 | 1.00 | 1.00 | 1.00 | 1.00 | 390 + 0.25 | 0.50 |
| 9A/12 | 780 | 1560 | 3120 | 3120 | 1.00 | 1.00 | 1.00 | 1.00 | 190 + 0.25 | 0.49 |
| 12F/12 | 3120 | 3120 | 3120 | 3120 | 1.00 | 1.00 | 1.00 | 1.00 | 780 + 0.25 | 0.50 |
| 13A/12 | 1560 | 3120 | 1560 | 3120 | 0.50 | 0.50 | 0.50 | 0.50 | 390 + 0.12 | 0.49 |
| 1F/13 | 1560 | 1560 | 3120 | 3120 | 1.00 | 1.00 | 1.00 | 1.00 | 390 + 0.25 | 0.50 |
| 3F/13 | 780 | 780 | 1560 | 1560 | 0.50 | 0.50 | 0.50 | 0.50 | 190 + 0.12 | 0.48 |
| 4A/13 | 3120 | 3120 | 6250 | 6250 | 0.50 | 0.50 | 1.00 | 1.00 | 780 + 0.12 | 0.49 |
| 5A/13 | 1560 | 1560 | 3120 | 3120 | 1.00 | 1.00 | 1.00 | 1.00 | 390 + 0.25 | 0.50 |
| 10A/13 | 1560 | 3120 | 1560 | 3120 | 1.00 | 1.00 | 1.00 | 1.00 | 390 + 0.25 | 0.50 |
| 13A/13 | 1560 | 1560 | 3120 | 3120 | 1.00 | 1.00 | 1.00 | 1.00 | 390 + 0.25 | 0.50 |
| 20A/13 | 1560 | 1560 | 3120 | 3120 | 1.00 | 1.00 | 1.00 | 1.00 | 390 + 0.25 | 0.50 |
| 23A/13 | 1560 | 3120 | 3120 | 3120 | 1.00 | 1.00 | 1.00 | 1.00 | 190 + 0.12 | 0.24 |
| 24F/13 | 780 | 1560 | 1560 | 1560 | 1.00 | 1.00 | 1.00 | 1.00 | 190 + 0.12 | 0.36 |
| 25F/13 | 1560 | 1560 | 3120 | 3120 | 1.00 | 1.00 | 1.00 | 1.00 | 390 + 0.25 | 0.50 |
| 26A/13 | 3120 | 3120 | 6250 | 6250 | 2.00 | 2.00 | 2.00 | 2.00 | 780 + 0.25 | 0.37 |
| 5F/14 | 3120 | 3120 | 6250 | 6250 | 1.00 | 1.00 | 1.00 | 1.00 | 780 + 0.12 | 0.37 |
| 10A/14 | 1560 | 1560 | 6250 | 6250 | 0.50 | 0.50 | 0.50 | 0.50 | 190 + 0.12 | 0.36 |
| 29A/14 | 1560 | 1560 | 3120 | 3120 | 1.00 | 1.00 | 1.00 | 1.00 | 390 + 0.12 | 0.37 |
| 3F/15 | 780 | 780 | 780 | 1560 | 1.00 | 1.00 | 1.00 | 1.00 | 190 + 0.12 | 0.36 |
| 4A/15 | 1560 | 1560 | 3120 | 3120 | 1.00 | 1.00 | 1.00 | 1.00 | 390 + 0.25 | 0.50 |
| 8F/15 | 1560 | 1560 | 1560 | 1560 | 0.50 | 0.50 | 0.50 | 0.50 | 390 + 0.12 | 0.49 |
| 30A/15 | 1560 | 1560 | 1560 | 3120 | 0.50 | 0.50 | 0.50 | 0.50 | 390 + 0.12 | 0.49 |
| 1A/16 | 1560 | 1560 | 3120 | 3120 | 1.00 | 1.00 | 1.00 | 1.00 | 390 + 0.25 | 0.50 |
| 5A/16 | 1560 | 1560 | 1560 | 1560 | 1.00 | 1.00 | 1.00 | 1.00 | 190 + 0.12 | 0.24 |
| 7F/16 | 3120 | 3120 | 3120 | 3120 | 0.50 | 0.50 | 0.50 | 0.50 | 780 + 0.12 | 0.49 |
| 14A/16 | 3120 | 3120 | 3120 | 3120 | 1.00 | 1.00 | 1.00 | 1.00 | 390 + 0.25 | 0.37 |
| 9F/13 | 1560 | 1560 | 3120 | 3120 | 0.12 | 0.12 | 0.12 | 0.12 | 390 + 0.03 | 0.50 |
| ATCC 43629 | 3120 | 3120 | 6250 | 6250 | 0.12 | 0.12 | 0.12 | 0.12 | 1560 + 0.03 | 0.75 |
*See Materials and Methods. #Combination of sub-MIC of P. vera L. ORS and LVX yielding the lowest FIC I, that is the best combination. Synergisms (FIC I ≤ 0.5) were detected in 31 out of 32 strains and an additive effect (FIC I > 0.5–4.0) was displayed in the reference H. pylori strain. Antagonism was not recorded (FIC I ≥ 4.0).