A Review of Extended Spectrum β-Lactamases: Definition and Types

Extended-spectrum β-lactamases (esbls) are defined as those bacterial enzymes which are capable to hydrolyze most beta-lactam antibiotics, including penicillins, cephalosporins, and the monobactam aztreonam and especially expanded spectrum cephalosporins such as ceftriaxone, cefotaxime, ceftazidime. worldwide, esbls are considered to be a serious threat, especially in hospitalized and immunocompromised patients. there is a growing prevalence and dissemination of esbls in bacterial isolates all over the world. individuals at high risk are those exposed to bacterial species harboring esbls as they result in treatment failure in many cases. thus, there is an urgent need to detect esbls producers with the formulation of strategic initiatives that participate in controlling their prevalence and dissemination. the current review aims to illustrate the importance of esbls and give a simple definition of their major types emphasizing on their substrate profiles and characteristics.