Stability in the presence of widespread β-lactamases. A prerequisite of the antibacterial activity of β-lactam drugs. Discussion

Bacterial resistance to the β-lactam drugs is extremely widespread, as a result of extensive drug use. Loss of susceptibility is primarily attributable to hydrolysis by inactivating enzymes, namely the β-lactamases. While the number of characterised β-lactamases may exceed 100, only a few are a problem in the treatment of community-acquired infections (TEM-1, TEM-2, SHV-1, BRO-1). Chromosomally mediated and extended-spectrum β-lactmases are usually dominant in nosocomial pathogens where oral antibiotic therapy is seldom used