<![CDATA[Introduction: Pseudomonas aeruginosa is a resilient nosocomial pathogen with intrinsic and acquired resistance to multiple antibiotics. A small percentage (2–3%) of carbapenem-resistant isolates carry mobile genetic elements encoding carbapenemases, making detection essential for therapy, infection control, and epidemiological surveillance. This study aimed to compare three phenotypic methods for detecting carbapenemase production in meropenem-resistant P. aeruginosa isolates: the Modified Hodge Test (MHT), Modified Carbapenem Inactivation Method (mCIM), and the VITEK-2 automated system. Methods: The mCIM followed standard protocols. Escherichia coli ATCC 25922 was cultured on Mueller-Hinton agar (MHA) according to CLSI 2024 guidelines. MHT steps followed the Clinical Microbiology Procedures Handbook (2016). Results from both tests were compared to those from the VITEK-2 system. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were assessed. Diagnostic accuracy was further analysed using ROC curves and AUC. Results: Of 21 meropenem-resistant P. aeruginosa isolates, 11 (52.4%) were identified as carbapenemase producers by VITEK-2 compact. MHT failed to detect any of these, showing a sensitivity of 0% and specificity of 100%. mCIM detected 10 of 11 carbapenemase producers (90.9% sensitivity) but had 50% specificity. The positive predictive value and negative predictive value were 0% and 47.6% for MHT, respectively, and 66.67% and 83.33% for mCIM, respectively. AUC values were 0.5 for MHT and 0.71 for mCIM, indicating mCIM performed more closely to VITEK-2 for carbapenemase detection. Conclusion: 52,4% of the meropenem-resistant P. aeruginosa isolates were carbapenemase producers based on VITEK-2 compact. Among phenotypic methods, mCIM demonstrated greater precision than MHT, compared with Vitek-2 compact as the standard, making it a useful screening tool. The selection of the carbapenemase detection method usage depends on each laboratory’s capabilities.]]>
