[Mechanisms of antibiotic resistance].

Antibiotics interfere with structural and regulatory elements of bacterial cells leading to growth arrest or cell death. Bacteria have evolved a variety of strategies to overcome the effects of antibiotics. Examples are enzymatic destruction, alteration of the target, efflux and permeability changes. Resistance towards the same substance can be mediated by several mechanisms. Efflux pumps can probably act as mediators of higher resistance development. Alteration of common targets can lead to cross-resistance against several classes of antibiotics. Genetic events, such as point mutations, transfer of plasmids and gen regulation, can mediate a rapid emergence of resistance. Therefore, substances like rifampicin should be only used in combination with other drugs. Accumulation of resistance genes under common regulatory control in integrons induces co-resistance against substances of different specificity. Detailed knowledge of resistance mechanisms, their evolution and dynamics is important for a rational use of antibiotics and other strategies against antibiotic resistance.