Bacterial resistance is a global problem with serious consequences: increased mortality, prolonged hospitalizations, higher surgical site infection rates, and elevated costs. Resistance monitoring allows epidemiological assessment, targeted antimicrobial therapy, and detection of new strains. Rapid immunoassay-based multiplex tests are available for phenotypic detection and differentiation of five carbapenemase families (KPC, OXA-48-like, VIM, IMP, and NDM) directly from bacterial colonies. The NG-Test Carba 5® is a rapid (≤ 15 min) in vitro multiplex immunoassay for the phenotypic detection and differentiation of these common carbapenemase families produced by Enterobacterales and Pseudomonas . Tests were performed between August 2024 and March 2025. Sixty carbapenem-resistant strains (49 Enterobacterales and 11 Pseudomonas aeruginosa ) identified by Vitek MS Prime® (BioMérieux) were tested using NG-Test Carba 5® to identify the resistance mechanism. Among Enterobacterales, 42 (70%) were KPC-producing, including 40 (95.24%) Klebsiella pneumoniae : 14 (35%) were sensitive to polymyxins, 27 (67%) to amikacin, 10 (25%) to gentamicin, and 21 (52.2%) to ceftazidime-avibactam. Two (4.76%) Escherichia coli isolates were both sensitive to polymyxin and gentamicin, one sensitive to amikacin, and the single isolate tested for ceftazidime-avibactam was sensitive. Beta-lactamases of the KPC, IMP, VIM, NDM, and OXA-48 types are the main enzymes produced by Enterobacterales that confer carbapenem resistance. A 2022 study showed that 77% of K. pneumoniae isolates were carbapenem-resistant due to KPC production, with polymyxin resistance at 29.5% and amikacin resistance at 19.6%. Strains resistant to these antimicrobials often have mutations in enzyme-coding alleles, mainly due to clinical antimicrobial use. This technology enables monitoring of resistance enzyme emergence and correlation between enzyme production and cross-resistance among antimicrobial classes.
Inacio et al. (2026) studied this question.