Carbapenems are considered the antibiotics of choice for the treatment of infections due to expanded-spectrum beta-lactamase producing Enterobacteriaceae (ESBL-PE). Their use is readily increasing because of the pandemic of ESBL-PE. However, the future of these drugs is challenged by the worldwide emergency of new resistance mechanisms in the same pathogens, particularly the carbapenemases. This resistance makes these drugs inactive and gives no therapeutic options for patients. Resistance to carbapenems is strongly associated with the use of these drugs, because of their large spectrum and strong impact on the host flora. Consequently, the correct use of these drugs is an important public health objective. In France, the CA-SFM (Committee on Antimicrobial of the French Society for Microbiology) has suggested alternative strategies with narrow spectrum beta-lactam for the treatment of ESBL-PE infections, including 3rd or 4th cephalosporins, cefoxitin and penicillins with beta-lactamase inhibitors. A recent analysis including 6 prospective cohort studies of bloodstream infections due to ESBL-producing Escherichia coli did not find an excess of mortality or a longer length of hospital stay for patients receiving penicillin with beta-lactamase inhibitors, as compared to patients treated with carbapenems, after adjusting by confounding factors. As patients receiving carbapenems seem to be more severely affected, the efficacy and safety of the alternative strategy remain unproved. A randomized study is therefore needed to evaluate a deescalating therapeutic strategy (switch the carbapenem to another beta-lactam for which the isolated pathogen is susceptible) in patients with well-defined ESBL-PE infections (usual sites of infections and non severe infections). The objectives of the present study are to demonstrate that the alternative strategy of deescalating therapy is not inferior to a strategy maintaining the carbapenem in terms of clinical cure, survival, lack of relapse and microbiological cure.
The study aims to evaluate a deescalating therapeutic strategy (switch the carbapenem to another beta-lactam for which the isolated pathogen is susceptible) in patients with well-defined ESBL-PE infections (usual sites of infections and non severe infections).