Antimicrobial Resistance and Stewardship in Surgical Departments: A Three-Year Single-Center Study

Background and Objectives: Antimicrobial resistance represents an important patient-safety concern in surgical departments, where empirical therapy, invasive procedures, intensive-care exposure, and healthcare-associated infections may contribute to adverse outcomes. This study aimed to describe temporal changes in institutional surveillance indicators related to microbiological testing coverage, selected antimicrobial-resistance phenotypes among clinical isolates, selected-antibiotic use profiles, and infection-related patient-safety outcomes in surgical departments and the intensive care unit of a Romanian tertiary clinical emergency hospital. Materials and Methods: A retrospective, longitudinal, single-center observational study was conducted from January 2023 to December 2025. Data were extracted from four institutional sources: microbiology laboratory records, pharmacy antimicrobial-use data, the infection prevention and control registry, and the clinical-administrative hospital information system. Microbiological testing coverage, the selected resistance phenotypes and healthcare-associated infection indicators were analyzed at semester level, with selected-antibiotic DDD profiles being analyzed at department level. Statistical analyses included descriptive statistics, Cochran–Armitage trend testing, Fisher’s exact test, and exploratory Spearman correlation. Results: The hospital-wide microbiological testing intensity index based on 1892 antibiogram events among 8141 antibiotic-treated patient records increased significantly from 18.05% (Semester I 2023) to 28.20% (Semester II 2025). When expressed as proportions of clinical isolates, E. coli MDR decreased from 10/136 isolates (7.4%) in Semester II 2023 to 0/122 isolates (0.0%) in Semester II 2025, and S. aureus MRSA+MLSB decreased from 11/36 isolates (30.6%) to 0/22 isolates (0.0%) over the same interval. Undetected several semesters, P. aeruginosa XDR/PDR accounted for 4/25 clinical isolates (16.0%) in the final semester. Selected-antibiotic DDD profiles differed across departments, with General Surgery and ICU accounting for the largest selected-antibiotic totals. Preoperative bacteriological screening increased from 48 tests in Semester I 2024 to 329 tests in Semester II 2025, MRSA-positive screening results decreasing from 10/48 (20.8%) to 2/329 (0.6%) over this interval, this finding being interpreted descriptively because the screened population and screening protocol could not be fully standardized retrospectively. Among 46 validated cases of healthcare or Clostridioides difficile infections, the overall mean length of stay was 15.35 days, peaking at 20.80 days in surgical departments. Conclusions: Routinely collected hospital data can generate useful institutional surveillance signals related to antimicrobial resistance, antimicrobial use, and infection-related patient safety. Increased microbiological testing coverage and lower proportions of selected MDR/MRSA phenotypes were observed during the study period, while late detection of XDR/PDR P. aeruginosa highlighted the need for sustained microbiological surveillance and department-specific stewardship review.