Activity of cefepime, carbapenems and new β-lactam/β-lactamase inhibitor combinations on complex and in Spain (SMART 2016-2022).

Objectives: To analyse the susceptibility profile to cefepime, carbapenems and new β-lactam/β-lactamase inhibitor combinations in complex and isolated from intra-abdominal, urinary, respiratory and bloodstream infections in the SMART (Study for Monitoring Antimicrobial Resistance Trends) surveillance study in Spain.

Methods: The susceptibilities of 759 isolates (473 complex and 286 ) collected in 11 Spanish hospitals from 2016 to 2022 were analysed following the EUCAST 2023 criteria. Molecular characterization looking for β-lactamase genes was performed through PCR and DNA sequencing analysis.

Results: complex showed resistance to third-generation cephalosporins in 25% of the cases, whereas was resistant in 35%. Regarding cefepime, resistance in was higher (10%) than in (2%). Carbapenems showed >85% activity in both microorganisms. Ceftazidime/avibactam, imipenem/relebactam and meropenem/vaborbactam had good activity against these microorganisms (>95%). In contrast, the activity of ceftolozane/tazobactam was lower (80%). A high proportion of the isolates resistant to new β-lactam/β-lactamase inhibitor combinations carried a carbapenemase, mainly OXA-48-like and VIM-1.

Conclusions: Ceftazidime/avibactam, imipenem/relebactam and meropenem/vaborbactam show high activity against both complex and isolates recovered in the SMART-Spain study. In contrast, differences have been found in the case of cefepime, showing more activity against than complex. These results are useful for antimicrobial stewardship programmes and for the implementation of local and national guidelines.