Carbapenemase Detection Methods in Clinical Microbiology: Conventional and Automated Approaches

Due largely to carbapenemase-producing bacteria such as Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter baumannii, antimicrobial resistance (AMR) has emerged as a major global health concern. Carbapenems were traditionally thought of as last-line treatments for multidrug-resistant (MDR) Gram-negative infections; however, these pathogens have reduced their efficacy. These pathogens are commonly associated with healthcare-associated infections, which increase morbidity, mortality, and lengthen hospital stays. Therefore, identifying carbapenemase activity is necessary for directing the right course of treatment, implementing infection control strategies, and assisting with antimicrobial stewardship initiatives. Traditional phenotypic techniques are still widely employed; however, methods such as disk diffusion, minimum inhibitory concentration (MIC) testing, and the modified Hodge test (MHT) are constrained by their slow turnaround times and challenges in identifying particular resistance mechanisms. Although enhanced sensitivity and specificity are provided by sophisticated biochemical assays such as Carba NP, Blue-Carba, and ethylenediaminetetraacetic acid (EDTA)-based techniques, problems with false positives and emerging variants still exist. Although cost and infrastructure requirements frequently limit their adoption, automated systems such as VITEK 2, BD Phoenix, MicroScan WalkAway, and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) improve diagnostic accuracy through quick, consistent, and repeatable results. Future developments, including AI-driven diagnostics, rapid point-of-care tools, genomic surveillance, and portable devices, highlight the urgent need for accessible solutions to improve patient outcomes, boost diagnostic capacity, and stop the spread of carbapenem resistance worldwide.