The role of new antibiotics in intra-abdominal infections in the era of multi-resistant bacteria.

: Complicated intra-abdominal infections (cIAI) are a substantial cause of morbidity at intensive care units. cIAI are frequently caused by multidrug-resistant strains of Enterobacteriaceae and Pseudomonas aeruginosa. In 592 cIAI patients from the First Department of Surgery, General University Hospital in Prague, we found an alarming increase in resistance of Escherichia coli to amoxicillin/clavulanic acid, piperacillin/tazobactam and third-generation cephalosporins in 2014-2017 (from 28.7% in 2014 to 37.5% in 2017, from 25% to 32% and from 2.3% to 5.6%, respectively). Ceftolozane/tazobactam and ceftazidime/avibactam are novel cephalosporins available for the treatment of cIAI. Ceftolozane/tazobactam is highly active against multidrug-resistant strains of P. aeruginosa, including carbapenem-resistant isolates. The new non-b-lactam b-lactamase inhibitor avibactam plus ceftazidime is active against carbapenemases-producing strains of Enterobacteriaceae. Both antibiotics are included in the new WSES guidelines for the management of cIAI.