In order to survive, bacteria develop sophisticated defence mechanisms to overcome the damaging effects of antibiotics on their metabolism.
Some bacteria have an innate natural resistance against particular antibiotics.
Other bacteria acquire resistance after repeated exposure to an antibiotic. The widespread resistance of certain bacterial strains to an antibiotic' action is one of the primary concerns regarding these substances. More commonly, genetic material is transferred directly or by a bacterial virus, a plasmid, from another bacterium or even another bacterial species. The development of resistance is being accelerated by these genetic transfers, especially in hospitals. These genetic modifications may alter the target site to prevent binding of the antibiotic to the inner membrane of the cell wall.