Beta-lactam
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A beta-lactam ring (β-lactam) or penam is a lactam with a heteroatomic ring structure, consisting of three carbon atoms and one nitrogen atom. The beta-lactam ring is part of several antibiotics, such as penicillin and cephalosporins, which are therefore also called beta-lactam antibiotics. These antibiotics work by inhibiting the bacterial cell wall synthesis. This has a lethal effect on bacteria, especially on Gram-positive ones. Bacteria can become resistant against beta-lactam antibiotics by expressing beta-lactamase.
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[edit] Beta Lactam Resistance
Because of the popularity of beta lactam drugs, certain bacteria have been able to develop counter-measures to traditional drug therapies. An enzyme called beta-lactamase is present in many different types of bacteria, which serves to 'break' the beta lactam ring, which effectively nullifies the antiobiotic's effectiveness.
[edit] Drug Response to Beta Lactam Resistance
As a response to bacterial resistance to beta lactam drugs, there are drugs, such as Augmentin, which are designed to disable the beta-lactamase enzyme. Augmentin is made of amoxicillin and clavulanic acid, both of which are beta lactam antibiotics. The clavulanic acid is designed to overwhelm all beta-lactamase enzymes, bind irreversibly to them, and effectively serve as an antagonist so that the amoxicillin is not affected by the beta-lactamase enzymes.
[edit] Bacteria Response to Beta Lactam Resistance Drugs
As a response to decreased efficacy of beta-lactamase, some bacteria have changed the proteins that beta-lactam antibiotics bind (the PBPs). Since the PBPs no longer recognize the beta-lactams, the antibiotics are essentially useless. This is the mechanism behind the Methicillin-resistant Staphylococcus aureus (MRSA).jvjbnbmbb
