What is "beta-lactamase"

n. (context biochemistry English) An enzyme produced by certain bacteria, responsible for their resistance to beta-lactam antibiotics such as penicillin.

n. enzyme produced by certain bacteria that inactivates penicillin and results in resistance to that antibiotic [syn: penicillinase]

Beta-lactamases (β-lactamases) are enzymes produced by bacteria (also known as penicillinase) that provide multi- resistance to β-lactam antibiotics such as penicillins, cephamycins, and carbapenems ( ertapenem), although carbapenems are relatively resistant to beta-lactamase. Beta-lactamase provides antibiotic resistance by breaking the antibiotics' structure. These antibiotics all have a common element in their molecular structure: a four-atom ring known as a β-lactam. Through hydrolysis, the lactamase enzyme breaks the β-lactam ring open, deactivating the molecule's antibacterial properties.

Beta-lactam antibiotics are typically used to treat a broad spectrum of Gram-positive and Gram-negative bacteria.

Beta-lactamases produced by Gram-negative organisms are usually secreted, especially when antibiotics are present in the environment.