产超广谱 β-内酰胺酶肠杆菌科细菌的感染与控制

超广谱β-内酰胺酶(ESBL)在肠杆菌科细菌中很常见,可水解超广谱头孢菌素,克拉维酸可抑制其水解作用。最主要的产ESBL的肠杆菌科细菌包括大肠杆菌、克雷伯菌属及变形杆菌属,在社区获得性感染中多见,也可见于医院获得性感染。近年来,产CTX-M型菌株明显增加,且逐渐超过SHV型及TEM型,成为目前最常见的β-内酰胺酶肠杆菌科细菌。出现产ESBL细菌感染的患者多合并相关的危险因素,如总住院时间长,ICU住院时间长,疾病严重,留置各种导管,接受肾脏替代治疗或机械通气等。防止患者之间传播对ESBL控制至关重要。正确的经验性抗生素对于治疗产ESBL细菌引起的感染非常重要。一旦ESBL阳性,即使体外药敏结果敏感,亦需慎用头孢菌素,此时应首选碳青霉烯类抗生素。

Extended-spectrum beta-lactamase-producing enterobacteriaceae:management and infection control

Enterobacteriaceae producing extended-spectrum beta-lactamases(ESBLs) are common,with effect of hydrolyzing extended-spectrum cephalosporins which can be inhibited by clavulanic acid.CTX-M has gradually replaced SHV and TEM variants,as the most common ESBL.ESBLs can be produced by Escherichia coli,Klebsiella species and Proteus species,while ESBL-producing Enterobacteriaceae may cause community-acquired infection and hospital-acquired infections.Risk factors of ESBL infection include prolonged hospital or ICU stay,severity of illness,presence of various catheters,renal replacement therapy and mechanical ventilation.Prevention of patient-to-patient transmission is the cornerstone of infection control of ESBL infection.Colonization of ESBL-producing enterobacteriaceae may be detected by surveillance culture of gastrointestinal tract.Appropriate empiric antibiotic therapy is crucial in the management of ESBL infections.Cephalosporins should be used cautiously to treat ESBL infections,even if in vitro susceptibility test suggests sensitive result Carbapenems remain the first choice to treat ESBL infections.