Beta-lactamases are enzymes  produced by bacteria(e.coli,KP) that provide resistance to ß-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 ß-lactam. Through hydrolysis, the lactamase enzyme breaks the ß-lactam ring open, deactivating the molecule's antibacterial properties.