[Bacterial resistance against beta-lactam antibiotics].

Beta-lactam antibiotics include the penicillins, cephalosporins, oxacephems (moxalactam), carbapenems (imipenem) and monobactams (azthreonam)--all with a common beta-lactam ring. Beta-lactam antibiotics block the synthesis and growth of the bacterial cell wall by binding to penicillin-binding proteins on the cytoplasma membrane. The bacteria may escape the effect of beta-lactam antibiotics by reducing the permeability of the cell wall (gramnegative bacteria), by producing beta-lactamases, by reducing the affinity for beta-lactams in their penicillin-binding proteins, or by developing tolerance to beta-lactam antibiotics. A combination of these resistance mechanisms may be found in the most resistant bacteria, such as Pseudomonas, Serratia and Enterobacter; bacteria often involved in nosocomial infections. Increased antibiotic pressure may select for beta-lactam resistance among other bacteria as well, such as staphylococci, streptococci, Haemophilus influenzae, meningococci and gonococci. Prudent use of antibiotics is mandatory essential to ensure a bactericidal effect of this most important and valuable group of antibiotics in the future.