Rectal Surveillance for Carbapenem-Resistant Klebsiella pneumoniae: Prevalence and Clinical Relevance in a Multidisciplinary Tertiary-Care Hospital

Background/Objectives: Carbapenem-resistant Klebsiella pneumoniae (CRKP) is a high-priority healthcare-associated pathogen. This study aimed to estimate rectal CRKP carriage and characterize same-patient clinical-site CRKP detection. Methods: We conducted a single-center retrospective microbiological surveillance study in a Romanian tertiary-care hospital between 1 January 2025 and 1 April 2026. Patient-level prevalence used all 3123 screened patients, with each patient counted once. CRKP recovery from rectal screening specimens was classified as gastrointestinal carriage; non-rectal recovery was reported as clinical-site detection and not as confirmed infection because clinical adjudication was not systematic. Results: Among 3123 screened patients, 712 (22.8%) had a positive rectal screen, 294 (9.4%) had resistant rectal K. pneumoniae carriage, and 168 (5.4%) had rectal CRKP carriage. Of these 168 carriers, 83 (49.4%) also had a retained non-rectal CRKP isolate; rectal recovery occurred first in 45, non-rectal recovery first in 36, and collection timestamps were identical in 2. Healthcare exposures, prior carbapenem-resistant Enterobacterales carriage, and admission-relative timing were analyzed descriptively using the full 168-patient denominator, with unavailable values retained as unknown. Invasive-device, intensive-care, recent hospitalization or readmission, and recent antimicrobial exposures were frequently documented. Admission-relative timing identified early detections, probable within-admission screen conversions, hospital-onset detections without a preceding negative screen, and indeterminate cases. Conclusions: Rectal CRKP carriage was frequent and commonly associated with same-patient CRKP detection at non-rectal clinical sites, indicating a substantial hospital-associated burden. In critically ill patients with sepsis or septic shock, known CRKP carriage should inform the choice of empirical CRKP-active therapy, with prompt de-escalation once microbiological findings and clinical response allow.