Abstract
Antibiotics are irreplaceable natural heritage. When antibiotics were introduced in the last century, humankind thought that the war against bacteria and infectious diseases is won.
However, bacteria can develop resistance to any of the drugs that were discovered. The most important mechanisms of resistance are limiting uptake of the antibiotic, modification of target place, active efflux and drug inactivation.
All these mechanisms can be intrinsic, independent of previous antibiotic exposure, or acquired. Acquired resistance may be transient or permanent.
The most widely used group of antibiotics is beta-lactams. One of the most important mechanism of resistance to beta-lactams is drug inactivation by beta-lactamases.
Beta-lactamases hydrolyze a specific site in the beta-lactam ring structure, causing the ring to open. Inhibitors of beta-lactamases are capable of protecting the molecule of the antibiotic by binding to these enzymes.