近年來革蘭氏陰性菌分泌超廣效乙內醯胺（Extended-spectrum-β-lactamase-producing; ESBL-producing）的盛行率均明顯地上升，已成為醫療上關切的課題。ESBLs 可水解破壞 具 oxyimino-β-lactam 結構的 cephalosporins （如 ceftazidime, cefotaxime ）、penicillins 、 monobactam 及 non-β-lactam 類等抗生素，並透過質體媒介在不同的菌株及菌種間傳遞，大 部份可在 Klebsiella pneumonia 菌株發現，但 Escherichia coli、Proteus mirabilis 及其他腸桿 菌發現的比例亦愈來愈高。
本文主要簡略介紹有關分泌超廣效乙內醯胺（ESBL）的分類、偵測方法、流行病學、 危險因子、臨床上 ESBL-producing 菌株引起感染的關聯性及適當的治療用藥等。
第三代 cephalosporins、第四代 cephalosporins、aminoglycosides、β-lactam/β-lactamase 抑制劑複合製劑及 fluoroquinolones 等抗生素並不適合ESBL-producing 細菌所引起的嚴重感 染症治療。Carbapenems（如 imipenem）仍是目前最具療效的用藥選擇，但過度使用亦成 為另一個值得關切的課題。臨床醫療人員更應審慎地使用抗生素，以控制抗藥性更進一步 的發展。
Extended-spectrum β-lactamase(ESBL)-producing gram-negative bacteria are a growing concern in human medicine and the prevalence rate is clearly increasing in recent years. ESBLs are plasmid-mediated enzymes that hydrolyze oxyimino-β-lactam agents such as cephalosporins(e.g. ceftazidime, cefotaxime), penicillins, monobactam and non-β-lactam antibiotics. These enzymes are transferable from strains and between bacterial species. They have been most commonly found in Klebsiella pneumonia, but are increasingly found in Escherichia coli, Proteus mirabilis and other members of the Enterobacteriaceae.
The screening and confirmatory tests of ESBL-producing strains are according to the methodology of Clinical and Laboratory Standards Institute（CLSI）guideline. Risk factors associated with ESBL
production include hospital stay, disease severity, the length of stay in ICU, intubation and mechanical ventilation, catheterization (e.g. central venous catheters, artery or urinary catheters) and prior extended-spectrum cephalosporins uses.
Many studies showed that third-generation and fourth-generation cephalosporins, aminoglycosides, β-lactam/β-lactamase inhibitor combination and fluoroquinolones should not be used to treat serious infections with ESBL-producing organisms, even in the presence of apparent susceptibility. Carbapenems (such as imipenem) are the treatment of choice for serious infections caused by ESBL-producing organisms but their overuse is a cause of concern. Due to the lack of novel agents to treat resistant infections, clinicians must use antibiotics judiciously and appropriately to control further development of resistance.
