Extended-spectrum beta-lactamase

An enzyme that hydrolyzes many penicillins and extended-spectrum cephalosporins, making bacteria resistant to these antibiotics. ESBLs are commonly found in Enterobacterales.

Beta-lactamase: An enzyme that inactivates beta-lactam antibiotics by hydrolyzing their beta-lactam ring. ESBLs are a subset of beta-lactamases distinguished by their expanded activity against cephalosporins.
Extended-spectrum cephalosporin: A cephalosporin antibiotic with activity against a broader range of bacteria than earlier generations. These drugs, especially third-generation agents, are characteristic ESBL substrates.
Antimicrobial susceptibility testing: Laboratory methods that determine whether microorganisms are inhibited by specified antimicrobial drugs. Testing helps identify resistance patterns that routine screening may otherwise miss.
Plasmid: A DNA molecule that replicates independently of a chromosome and can carry transferable genes. ESBL genes often travel on plasmids that also carry resistance to other antibiotics.
AmpC beta-lactamase: A class C beta-lactamase that can hydrolyze many cephalosporins and is not inhibited by clavulanic acid. AmpC can resemble ESBL resistance patterns but differs in enzyme class and inhibitor response.
Beta-lactam ring: A four-membered cyclic amide structure essential to the antibacterial activity of beta-lactam antibiotics. ESBLs hydrolyze this structure, disabling the antibiotics they target.
Penicillin: A beta-lactam antibiotic that inhibits bacterial cell-wall synthesis. Many ESBLs also hydrolyze penicillins, the antibiotic family named in their spectrum.
Carbapenem: A broad-spectrum beta-lactam antibiotic generally stable against ESBL hydrolysis. Carbapenems have often been used for serious infections caused by ESBL-producing bacteria.
Horizontal gene transfer: The movement of genetic material between organisms other than through parent-to-offspring inheritance. Transfer of ESBL-bearing plasmids spreads resistance between bacterial strains and species.
Carbapenemase: A beta-lactamase capable of hydrolyzing carbapenem antibiotics, among other beta-lactams. Unlike typical ESBLs, carbapenemases can directly compromise carbapenem activity.

Linked from 10 pages