Comparison of in vitro activity of cefepime-enmetazobactam and other carbapenem-sparing agents for gram negative uropathogens

Authors: Kalaivani Ramakrishnan, Arunava Kali, Sarah Korah, Thouheedha Banu S, Srirangaraj Sreenivasan

DOI: 10.18231/j.ijmmtd.12708.1760517812

Keywords: Cefepime-enmetazobactam, Carbapenem-sparing antibiotic, Extended-Spectrum β-Lactamase, Multidrug-resistance

Abstract: Background: Urinary tract infections (UTIs) caused by Gram-negative bacteria are an emerging therapeutic concern due to resistance to third-generation cephalosporins associated with Extended-spectrum beta-lactamases (ESBLs). This study aimed to evaluate the in vitro activity of cefepime-enmetazobactam compared to other carbapenem-sparing agents against Gram-negative uropathogens. Materials and Methods: A total of 139 non-duplicate Gram-negative bacterial isolates were recovered from urine samples of patients with UTIs between February and May 2025. Antimicrobial susceptibility testing was performed for cefepime-enmetazobactam, cefepime, cefoperazone-sulbactam, piperacillin-tazobactam, meropenem and fosfomycin. ESBL production and carbapenem resistance were determined as per CLSI guidelines. Results: Among the 139 patients, females constituted 78.4% (n=109), and the most affected age group was 21–40 years (45.3%). Escherichia coli was the predominant isolate (67.6%), followed by Klebsiella pneumoniae (17.3%) and Pseudomonas aeruginosa (5.8%). ESBL production was detected in 29.5% (n=41), while carbapenem resistance was observed in 12.2% (n=17). Among all isolates, resistance to cefepime was 46% (n=64), followed by piperacillin-tazobactam (16.5%), cefoperazone-sulbactam (12.2%), and cefepime-enmetazobactam (13.7%). Cefepime-enmetazobactam demonstrated strong activity against ESBL producers (97.5%, n=40), however, had poor activity against carbapenem-resistant organisms (CRO). Among the 64 cefepime-resistant isolates, 45 (70.3%) were susceptible to cefepime-enmetazobactam, reflecting a significant restoration of susceptibility. Conclusion: Cefepime-enmetazobactam displayed superior in vitro effect compared to other carbapenem-sparing agents, particularly against cefepime-resistant and ESBL-producing uropathogens. These findings highlight its potential as an effective substitute for carbapenems in the treatment of UTIs caused by ESBL producing Gram-negative bacteria.