TEM-type beta-lactamase (TEM)

**TEM-type beta-lactamase** is a class A serine hydrolase enzyme that confers resistance to beta-lactam antibiotics by catalyzing the hydrolysis of the beta-lactam ring, thereby inactivating the drug[1][2][4]. Originally described in *Escherichia coli* (E. coli) in 1963, TEM-1 is the most common variant and has become widely prevalent among Enterobacteriaceae and other Gram-negative bacteria, mediating high-level resistance to penicillins and early-generation cephalosporins[1][4]. Amino acid substitutions around the active site can generate extended-spectrum beta-lactamases (ESBLs), which allow hydrolysis of newer cephalosporins and broaden the spectrum of resistance[1][4]. The structure and mechanism of TEM enzymes make them important targets for beta-lactamase inhibitor drugs, but the rapid evolution of TEM variants continues to pose a significant clinical challenge due to emerging resistance[1][2][4].

Other names

TEM-1 beta-lactamaseclass A beta-lactamaseextended-spectrum beta-lactamase (certain variants)ESBL (for extended-spectrum variants)TEM-10TEM-12TEM-26TEM-52TEM-64TEM-72 (individual variants)

Hydrolysis of the beta-lactam ring of antibiotics, inactivating them. Extended-spectrum TEM variants can hydrolyze a broader range of beta-lactams, including some cephalosporins. Susceptibility to inhibition by beta-lactamase inhibitors (especially in some variants).