Carbapenem-Resistant and Extensively Drug-Resistant Gram-Negative Healthcare-Associated Infections in a Romanian Tertiary Infectious Diseases Hospital: Phenotypic Landscape, Stewardship Gaps and Outcomes (2024–2025)

Abstract

Background/Objectives: Romania reports among the highest rates of carbapenem-resistant Gram-negative bacteria in the European Union, but patient-level data on healthcare-associated infections (HAIs) are scarce. We characterised carbapenem resistance, in-hospital outcomes, and carbapenem prescribing in a 24-month HAI cohort. Methods: This was a retrospective study of 315 patients with microbiologically confirmed HAI (2024–2025) at a tertiary infectious diseases hospital, contributing 243 Gram-negative isolates. Carbapenem resistance was determined by the hospital laboratory; extensively drug-resistant (XDR) status, defined as susceptibility to no more than two of the antimicrobial classes tested, was assigned under the hospital surveillance protocol. Risk-factor analysis was exploratory. Results: Of 243 Gram-negative isolates, 162 (66.7%) were carbapenem-resistant and 150 of these (92.6%) were designated XDR. Resistance reached 90.6% in Klebsiella pneumoniae and 83.0% in Acinetobacter baumannii, against 33.3% in Pseudomonas aeruginosa and 0% in Escherichia coli, and occurred at every infection site. No routinely recorded characteristic distinguished resistant from susceptible infection after adjustment (area under the curve 0.62). In-hospital death was associated with intensive care transfer (adjusted odds ratio 6.92, 95% confidence interval 3.33–14.38) but not with carbapenem resistance (1.14, 0.52–2.50). Of 92 carbapenem recipients, 54 (58.7%) had a carbapenem-resistant isolate, against which carbapenems are inactive, and 12 (13.0%) had a Gram-negative isolate that was neither carbapenem-resistant nor extended-spectrum β-lactamase-producing. Conclusions: At this centre, carbapenem resistance in Gram-negative HAI is endemic, could not be predicted from the routinely recorded characteristics examined, and exceeds European surveillance figures only among the Enterobacterales. No independent association with mortality was detected, although the susceptible comparison group was small. The XDR proportion was assigned under the hospital surveillance protocol and is not directly comparable with category-based estimates. Because antibiotic exposure was recorded without timing relative to culture sampling, these data support prospective audit of carbapenem prescribing rather than demonstrating missed de-escalation.