Research Information System
Current Microbiology, vol.83, no.4, 2026 (SCI-Expanded, Scopus)
The global incidence of carbapenem resistance is increasing due to the presence of beta-lactamases such as carbapenemases. This study evaluated the in vitro antimicrobial activities and metabolic activities of biofilm cells of two carbapenem beta-lactamase inhibitor combinations, imipenem-cilastatin+relebactam and meropenem+vaborbactam, against imipenem and/or meropenem resistant, metallo-beta-lactamase negative clinical isolates of Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae, Escherichia coli, and Enterobacter spp. Both combinations demonstrated antibacterial activity, particularly against P. aeruginosa and E. coli. MBCs were found higher than MICs against all microorganisms. Imipenem-cilastatin+relebactam was the most effective agent against K. pneumoniae and Enterobacter spp. biofilms, while meropenem-vaborbactam showed greater activity against P. aeruginosa, A. baumannii, and E. coli biofilms. This study presents new results by characterizing the antibiofilm activity of these combinations for the first time in clinical isolates from Türkiye. Synergy with colistin was observed in selected isolates, and no antagonist effect was detected in any of the strains studied. Therefore, the study results suggest that imipenem-cilastatin+relebactam and meropenem+vaborbactam combinations, alone or in combination with colistin, could play an important role in the treatment of carbapenem-resistant Gram-negative bacteria, including biofilm-associated diseases.