[Infectious diseases caused by carbapenemase-producing Enterobacteriaceae--a particular challenge for antibacterial...

Enterobacteriaceae species such as Escherichia coli and Klebsiella pneumoniae are among the most common human pathogens. They are responsible for a wide range of community-acquired and nosocomial diseases. Many of the illnesses caused by these bacteria could be treated with beta-lactams for several decades. The increasing use of carbapenems for the treatment of diseases caused by Enterobacteriaceae expressing extended spectrum beta-lactamases, however, lead to the selection and spread of carbapenemase-producing pathogens. Such bacteria are not only resistant to virtually all beta-lactams, but also to numerous other antibiotics such as quinolones, co-trimoxazole, nitrofurantoin, tetracyclines and most aminoglycosides. During the last years, carbapenemase-producing Enterobacteriaceae have spread into almost all regions of the world. Klebsiella pneumoniae carbapenemases (KPC, belonging to Ambler class A), OXA-48 enzymes and their derivatives (belonging to Ambler class D) as well as some metallo-beta-lactamases (Ambler class B) such as NDM, VIM and IMP are the most important carbapenemases produced by Enterobacteriaceae strains. In Germany, the metallo-carbapenemase GIM-1, which has never been proven in bacteria outside Germany, is also of clinical significance. There is no established antibacterial therapy for these difficult-to-treat diseases. For the treatment of severe diseases caused by carbapenemase-producing bacteria, fosfomycin, gentamicin and tigecycline, polymyxins such as polymyxin B or colistin as well as carbapenems, are frequently applied. Combination antibiotic treatment may be more effective than monotherapy for severe ill patients with serious diseases. The most promising new treatment options arise with the development of avibactam. This non-beta-lactam beta-lactamase inhibitor shows good activity against (nearly) all class A and class C beta-lactamases (including strains expressing class A carbapenemases and/or derepressed AmpC enzymes) as well as OXA-48 carbapenemases. It may be used successfully in combination with ceftazidime, ceftaroline or aztreonam.