Alternatives to carbapenems in ESBL-producing Escherichia coli infections

Objectives

The authors had for objective to assess the activity of a wide panel of antibiotics on extended-spectrum-β-lactamase producing Escherichia coli isolates (ESBL-Ec), because of the sharp increase of their frequency, leading to an increased use of carbapenems.

Material and methods

We selected 100 ESBL-Ec in which ESBLs were identified by PCR and sequencing, between 2009 and 2010. We determined the MICs of amoxicillin-clavulanate, piperacillin-tazobactam, temocillin, mecillinam, cefoxitin, cefotaxime, ceftazidime, aztreonam, tigecycline, nitrofurantoin, and fosfomycin using reference methods. The susceptibility profiles were defined according to EUCAST 2012 recommendations.

Results

Fosfomycin, nitrofurantoin, and pivmecillinam were active against more than 90% of isolates and remain excellent choices for the oral treatment of urinary tract infections (UTIs). Temocillin and piperacillin-tazobactam are also good candidates for the treatment of pyelonephritis or bloodstream infections. Only 27, 23, and 8% of isolates were susceptible to ceftazidime, cefepime, and cefotaxime, respectively.

Conclusion

Our study results prove that in many cases, there are non-carbapenem alternatives for the treatment of ESBL-Ec infections.