Table 2.
MIC (μg/mL) of antibiotics for specific Lactobacillus strains as determined by gradient diffusion using M.I.C. Evaluator® strips. The probiotic L. plantarum 14917 served as a reference strain.
| Agent | SP3 | SP16 | SP18 | SP10 | SP21 | SP22 | SP27 | SP30 | SP33 | SP36 | L. plantarum ATCC 14917 | Cut-Off a |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| (MIC μg/mL) | ||||||||||||
| Amoxycillin | 2.28 ± 0.27 | 1.58 ± 0.11 * | 3.7 ± 0.11 | 3.84 ± 0.31 * | 4.41 ± 0.79 * | 2.76 ± 0.91 | 3.10 ± 0.17 | 4.15 ± 0.23 * | 3.75 ± 0.29 * | 3.84 ± 0.59 * | 2.86 ± 0.78 | n.r. b,c |
| Amoxycillin + Clavulanic acid | 1.57 ± 0.31 | 1.14 ± 0.15 * | 1.76 ± 0.15 * | 1.14 ± 0.13 * | 0.49 ± 0.05 * | 1.44 ± 0.19 * | 1.95 ± 0.11 * | 1.25 ± 0.51 * | 0.84 ± 0.11 * | 1.24 ± 0.29 * | 2.67 ± 0.15 | n.r. b,c |
| Ampicillin | 0.38 ± 0.07 | 0.99 ± 0.05 * | 1.26 ± 0.09 * | 2.08 ± 0.19 * | 1.76 ± 0.21 * | 1.76 ± 0.09 * | 1.29 ± 0.23 * | 1.47 ± 0.09 * | 0.76 ± 0.08 * | 0.76 ± 0.31 * | 0.58 ± 0.33 | 4 b |
| Clindamycin | 0.73 ± 0.05 | 1.14 ± 0.26 * | 1.54 ± 0.20 * | 0.96 ± 0.08 | 2.29 ± 0.21 * | 1.33 ± 0.21 * | 1.12 ± 0.10 * | 1.51 ± 0.15 * | 1.95 ± 0.21 * | 0.97 ± 0.13 * | 0.67 ± 0.20 | 1 b |
| Erythromycin | 0.34 ± 0.11 * | 0.43 ± 0.09 * | 1.08 ± 0.11 | 1.79 ± 0.15 * | 1.89 ± 0.09 * | 1.81 ± 0.15 * | 0.35 ± 0.05 * | 1.23 ± 0.19 | 1.74 ± 0.19 * | 1.41 ± 0.10 | 1.00 ± 0.87 | 1 b |
| Gentamycin | 5.18 ± 0.12 * | 6.57 ± 1.15 * | 5.73 ± 0.31 * | 8.41 ± 0.71 * | 7.29 ± 0.31 * | 9.15 ± 0.47 * | 8.71 ± 1.11 * | 5.21 ± 0.79 * | 6.43 ± 0.31 * | 6.08 ± 1.71 * | 3.33 ± 1.15 * | 32 b |
| Metronidazole | 103.4 ± 22.7 * | 144.1 ± 21.9 * | 175.2 ± 30.4 * | 148.1 ± 3.08 * | 77.9 ± 10.23 * | 104.4 ± 18.3 * | 200.1 ± 21.8 * | 153.1 ± 21.39 * | 148.3 ± 20.15 * | 138.1 ± 19.2 * | >256 | n.r. b,c |
| Tetracyclinne | 4.13 ± 0.10 * | 5.29 ± 0.39 * | 9.55 ± 0.81 * | 5.36 ± 0.71 * | 6.23 ± 0.58 * | 4.48 ± 0.93 * | 5.12 ± 0.76 * | 6.53 ± 0.87 * | 10.89 ± 0.95 * | 14.08 ±1.39 | 13.3 ± 4.62 | 4 b |
| Tigecycline | 0.35 ± 0.05 | 0.47 ± 0.08 | 0.41 ± 0.15 | 0.49 ± 0.08 | 0.64 ± 0.07 * | 0.59 ± 0.11 * | 0.62 ± 0.13 * | 0.59 ± 0.11 * | 0.61 ± 0.08 * | 0.44 ± 0.05 | 0.33 ± 0.14 | n.r. b,c |
| Vancomycin | >256 | >256 | >256 | >256 | >256 | >256 | >256 | >256 | >256 | >256 | >256 | n.r. b,c |
* Denotes a statistically significant difference in MIC values between the corresponding and the reference strain (L. plantarum ATCC 14971). a Breakpoints are referred to L. casei/paracasei strains. EFSA breakpoints for other types of LABs are slightly different. b Strains with MIC higher than the breakpoints are considered as resistant according to EFSA. c not required.