Multidrug-Resistant Bacteria in Surgical Intensive Care Units: Antibiotic Susceptibility and β-Lactamase Characterization.

Multidrug-resistant (MDR) bacteria of the utmost importance are extended-spectrum β-lactamase (ESBL) and carbapenemase-producing Enterobacterales (CRE), carbapenem-resistant (CRAB), carbapenem-resistant (CRPA), methicillin-resistant (MRSA) and vancomycin-resistant spp. (VRE). In this study, an evaluation of MDR bacteria in surgical intensive care units in a tertiary referral hospital was conducted. The study aimed to characterize β-lactamases and other resistance traits of Gram-negative bacteria isolated in surgical intensive care units (ICUs). Disk diffusion and the broth dilution method were used for antibiotic susceptibility testing, whereas ESBL screening was performed through a double disk synergy test and an inhibitor-based test with clavulanic acid. A total of 119 MDR bacterial isolates were analysed. ESBL production was observed in half of the , 90% of the and all of the and isolates. OXA-48 carbapenemase, carried by the L plasmid, was detected in 34 and one and complex isolates, whereas NDM occurred sporadically and was identified in three isolates. OXA-48 positive isolates coharboured ESBLs belonging to the CTX-M family in all but one isolate. OXA-23 carbapenemase was confirmed in all isolates. The findings of this study provide valuable insight of resistance determinants of Enterobacterales and which will enhance surveillance and intervention strategies that are necessary to curb the ever-growing carbapenem resistance rates.