beta-lactamase

β-lac·ta·mase

(lak'tă-mās),

An enzyme produced by many species of bacteria that disrupts the four-membered β-lactam ring of penicillin and cephalosporin groups of antibiotics, destroying their antimicrobial activity. The ability of an organism to produce a β-lactamase may be chromosomal and constitutive or a plasmid-associated acquired property.

Synonym(s): cephalosporinase, lactamase, penicillinase (1)

β-lactamase

/β-lac·ta·mase/ (lak´tah-mās) any of a group of enzymes, produced by almost all gram-negative bacteria, that hydrolyze the β-lactam ring of penicillins and cephalosporins, destroying their antibiotic activity. Individual enzymes may be called penicillinases or cephalosporinases based on their specificities.

beta-lactamase

(bā′tə-lăk′tə-mās′, -māz′, bē′-)

n.

Any of various enzymes that hydrolyze and inactivate beta-lactam antibiotics such as penicillin, found in many antibiotic-resistant bacteria.

beta-lactamase

[-lak′təmāz]

Etymology: lactam, a cyclic amide, ase, enzyme

a bacterial enzyme that catalyzes the hydrolysis of the beta-lactam ring of some penicillins and cephalosporins, producing penicilloic acid and rendering the antibiotic ineffective. Also called cephalosporinase, penicillinase.

be·ta-lac·ta·mase

(bā'tă lak'tā-mās)

An enzyme produced by many species of bacteria that disrupts the four-membered β-lactam ring of penicillin and cephalosporin groups of antibiotics, destroying their antimicrobial activity.
Synonym(s): penicillinase.

β-lactamase

either of two enzymes: β-lactamase I is penicillinase; β-lactamase II is cephalosporinase.