TABLE 2.
Susceptibility to antimicrobial agents and putative resistance genes in bifidobacteriaa
| Clade and patient no. | Species | PEN |
MTZ |
CLI |
PIP-TAZ |
VAN |
CTX |
CIP |
MRP |
TET |
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| MIC (mg/liter) | Res. genes | MIC (mg/liter) | Res. genes | MIC (mg/liter) | Res. genes | MIC (mg/liter) | Res. genes | MIC (mg/liter) | Res. genes | MIC (mg/liter) | Res. genes | MIC (mg/liter) | Res. genes | MIC (mg/liter) | Res. genes | MIC (mg/liter) | Res. genes | ||
| Clade I | |||||||||||||||||||
| 10 | B. breve | 0.25 | >256 | 0.064 | 0.25 | 0.50 | 1 | 1 | mfd, gyrA | 1 | 1 | ||||||||
| 7 | B. breve | 0.25 | >256 | 0.016 | 0.064 | 0.25 | 8 | >32 | mfd, gyrA | 1 | 32 | tet(T) | |||||||
| Clade II | |||||||||||||||||||
| 14 | B. longum subsp. infantis | 0.125 | 32 | 0.25 | 0.064 | 0.25 | 0.25 | 4 | mfd, gyrA | 0.016 | 4 | ||||||||
| 15 | B. longum subsp. infantis | 0.125 | 32 | 0.25 | 0.064 | 0.25 | 0.25 | 4 | mfd, gyrA | 0.016 | 4 | ||||||||
| 13 | B. longum subsp. infantis | 0.125 | 16 | 0.25 | 0.064 | 0.25 | 0.25 | 4 | mfd, gyrA | 0.016 | 4 | ||||||||
| 4 | B. longum subsp. infantis | 0.25 | >256 | 0.064 | lmrD | 0.125 | 0.25 | 0.50 | >32 | mfd, gyrA | 0.064 | 1 | |||||||
| Clade III | |||||||||||||||||||
| 12 | B. longum subsp. longum | 0.50 | >256 | 0.125 | 1 | 0.50 | 0.50 | 0.5 | mfd, gyrA | 1 | 32 | ||||||||
| 9 | B. longum subsp. longum | 0.50 | >256 | 0.064 | 0.5 | 0.50 | 1 | >32 | mfd, gyrA | 0.25 | 0.50 | ||||||||
| 3 | B. longum subsp. longum | 0.50 | AIE | 8 | 0.064 | 0.50 | 0.25 | 1 | AIE | >32 | mfd, gyrA | 0.50 | 1.0 | AIE | |||||
| 5 | B. longum subsp. longum | 0.25 | 8 | 0.032 | 0.25 | 0.50 | 0.50 | >32 | mfd, gyrA | 0.064 | 0.50 | ||||||||
| 6 | B. longum subsp. longum | 0.25 | 8 | 0.064 | 1 | 0.25 | 1 | >32 | mfd, gyrA | 0.125 | 0.50 | ||||||||
| 2 | B. longum subsp. longum | 0.50 | >256 | >256 | 0.5 | 0.25 | 1 | >32 | mfd, gyrA | 0.25 | 1.0 | ||||||||
| 1 | B. longum subsp. longum | 0.50 | 8 | 0.064 | 0.25 | 0.25 | 1 | >32 | mfd, gyrA | 0.125 | 0.50 | ||||||||
| Clade IV | |||||||||||||||||||
| 11 | B. animalis | 0.25 | 8 | 0.032 | 0.25 | 0.50 | 0.50 | 0.5 | mfd, gyrA-gyrB | 0.064 | 16 | tet(T) | |||||||
| 8 | B. animalis | 0.50 | 128 | 0.032 | 0.50 | 1 | 2 | >32 | mfd, gyr-gyrB | 0.125 | 16 | tet(T) | |||||||
PEN, penicillin; MTZ, metronidazole; CLI, clindamycin; PIP-TAZ, piperacillin-tazobactam; VAN, vancomycin; CTX, cefotaxime; CIP, ciprofloxacin; MRP, meropenem; TET, tetracycline; Res. genes, groups of genes presumed to predict resistance (Comprehensive Antibiotic Resistance Database [CARD]); AIE, antibiotic inactivation enzymes (encompasses several enzymes that catalyze the inactivation of an antibiotic); lmrD, lincomycin resistance gene; mfd, mutation frequency decline gene involved in strand-specific DNA repair (overexpression may lead to ciprofloxacin resistance); gyrA, Mycobacterium tuberculosis gyrA mutant; gyrB, Mycobacterium tuberculosis gyrB mutant; tet(T), tetracycline resistance gene.