Activity of Imipenem-Relebactam and Meropenem-Vaborbactam against Carbapenem-Resistant, SME-Producing Serratia...

Area of Science:

• Microbiology
• Infectious Diseases
• Antimicrobial Resistance

Background:

• Serratia marcescens enzyme (SME) is a chromosomally encoded carbapenemase.
• Carbapenemase-producing Enterobacterales (CPE) pose a significant global health threat.
• There is a critical need for effective treatments against SME-producing bacteria.

Purpose of the Study:

• To evaluate the in vitro activity of various β-lactam/β-lactamase inhibitors and comparators against SME-producing Serratia marcescens.
• To determine the bactericidal activity of promising agents using time-kill analyses.

Main Methods:

• Broth microdilution was used to test antimicrobial susceptibility against 8 SME-producing isolates.
• Time-kill assays were performed on 4 selected isolates to assess bactericidal activity.

Main Results:

• All 8 isolates were resistant to imipenem, imipenem-relebactam, and meropenem.
• All isolates remained susceptible to ceftazidime, ceftazidime-avibactam, and meropenem-vaborbactam.
• Meropenem-vaborbactam demonstrated bactericidal activity against 4 out of 4 isolates tested.

Conclusions:

• Meropenem-vaborbactam exhibits promising in vitro activity against SME-producing Serratia marcescens.
• Meropenem-vaborbactam may represent a viable therapeutic option for severe SME-producing infections.
• Further clinical investigation is warranted to confirm the efficacy of meropenem-vaborbactam.