Background/Objectives: Antimicrobial resistance (AMR) remains a major global threat, with the COVID-19 pandemic influencing its dynamics, although its overall impact remains uncertain. This study analyzed seven-year AMR trends, including the pandemic period, in a tertiary care hospital in Greece that served as a COVID-19 referral center. Methods: Multiresistant bacteria isolated from all biological specimens of hospitalized patients between January 2018 and December 2024 were recorded and classified as multidrug- (MDR), extensively drug- (XDR), or pandrug-resistant (PDR). Overall AMR was defined as the sum of these categories. Annual incidences of overall AMR, its categories, and predominant Gram-negative (A. baumannii, K. pneumoniae, P. aeruginosa) and Gram-positive [methicillin-resistant S. aureus (MRSA), vancomycin-resistant Enterococcus (VRE)] pathogens were analyzed for the entire hospital and by sector (medical, intensive care unit [ICU], surgical). Bloodstream infection (BSI) AMR was also evaluated. Trend analysis was performed using Joinpoint regression. Results: Overall AMR exhibited a transient peak around 2021 across the hospital, except in the surgical sector. A significant rise in average annual percentage change (AAPC) occurred only in the medical sector (p < 0.001). PDR incidence increased hospital-wide (p < 0.001). K. pneumoniae, P. aeruginosa, MRSA, and VRE rose significantly in the medical sector, whereas ICU incidences remained largely stable despite the 2021 peak. A. baumannii showed no significant change. BSI-related AMR increased in the medical sector (p < 0.001) but not in the ICU (p = 0.2). Conclusions: Although overall AMR did not rise uniformly, PDR organisms increased hospital-wide. These findings support updating empiric therapy guidelines, reinforcing infection prevention measures, and translating surveillance data into targeted stewardship actions to enhance patient care.

Background/Objectives: The aim of the present study is to report an outbreak of bloodstream infections caused by Serratia marcescens in patients undergoing postoperational procedures in the Cardiothoracic Department and to describe the epidemiological investigations and control measures undertaken. A cluster of bacteremia due to Serratia marcescens was identified in blood cultures from postoperative patients in the Cardiothoracic Surgery Department in November 2023. Methods: Active surveillance by the hospital’s prevention and control team was initiated. Interviews with nurses and sanitary personnel and reviews of the most common procedures, such as hand washing, bladder catheterization, and intravenous catheter care, were performed. Culturing samples from hospital personnel, postoperative patients, and the environment, including pressure transducers, tap water, soap, therapeutic solutions, antiseptics, respirators, and various intravenous preparations, were drawn up. Overall, 225 samples were collected, including 149 blood cultures, and these were all sent to the Hospital’s Microbiology Laboratory. Results: Twenty-three out of forty-seven postoperative patients had positive blood cultures for Serratia marcescens. All the postoperative patients involved in the outbreak received cefepime according to antimicrobial susceptibility testing. Three pre-prepared flushing syringes were found to be positive for Serratia marcescens as well. The Cardiothoracic Department was kept under surveillance with hand hygiene measures, infusion preparation, medical device use, and cleaning procedures reviewed by the infection’s prevention and control team. Conclusions: Undoubtedly, nosocomial outbreaks represent an important health issue regarding morbidity, mortality, and costs. Timely interventions by the hospital’s infection prevention and control team may be life-saving under these circumstances.

In our hospital, adherence to the guidelines for peri-operative antimicrobial prophylaxis (PAP) is suboptimal, with overly long courses being common. This practice does not offer any incremental benefit, and it only adds to the burden of antimicrobial consumption, promotes the emergence of antimicrobial resistance, and it is associated with adverse events. Our objective was to study the effect of an electronic reminder on the adherence to each element of PAP after cardiac surgery. We conducted a single center, before and after intervention, prospective cohort study from 1 June 2014 to 30 September 2017. The intervention consisted of a reminder of the hospital guidelines when ordering PAP through the hospital information system. The primary outcome was adherence to the suggested duration of PAP, while secondary outcomes included adherence to the other elements of PAP and incidence of surgical site infections (SSI). We have studied 1080 operations (400 pre-intervention and 680 post-intervention). Adherence to the appropriate duration of PAP increased significantly after the intervention [PRE 4.0% (16/399) vs. POST 15.4% (105/680), chi-square p < 0.001]; however, it remained inappropriately low. Factors associated with inappropriate duration of PAP were pre-operative hospitalization for 4 h, while there were significant differences between the chief surgeons. Unexpectedly, the rate of SSIs increased significantly during the study (PRE 2.8% (11/400) vs. POST 5.9% (40/680), chi-square p < 0.019). The implemented intervention achieved a relative increase in adherence to the guideline-recommended PAP duration; however, adherence was still unacceptably low and further efforts to improve adherence are needed.