Mechanisms of bacterial resistance
| Type of resistance | Cause | Resulting phenotype |
|---|---|---|
| Acquired [29] | Mutations, horizontal gene transfer | Acquired antibiotic resistance in MDR and XDR strains (β-lactamase production, colistin resistance, polymyxin resistance…) |
| Adaptive [27, 28] | Temporary change in phenotype due to environmental causes, quickly reversible | Efflux pump upregulation |
| Intrinsic [30] | Resistance not caused by acquired or adaptive abilities | Outer membrane, efflux pump, biofilm |