β-Lactamase
![](/Images/godic/202501/23/PDB_1bsg_EBI4519.jpg")
![Core structure of penicillins (top) and cephalosporins (bottom). β-lactam ring in red.](/Images/godic/202501/23/Beta-lactam_antibiotics_example_1.svg4519.png")
![Escherichia coli bacteria on the right are sensitive to two beta-lactam antibiotics, and do not grow in the semi-circular regions surrounding the antibiotics. E. coli bacteria on the left are resistant to beta-lactam antibiotics, and grow next to one antibiotic (bottom) and are less inhibited by another antibiotic (top).](/Images/godic/202501/23/ESBL_Stokes4519.jpg")
Beta-lactamases are enzymes (EC3.5.2.6) produced by bacteria(Also known as Penicillinase ) that provide 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.