Rectal versus groin screening for multidrug-resistant organisms: pathogen-specific diagnostic yield in a tertiary-care hospital

Abstract Objective: To evaluate the pathogen-specific diagnostic yield of rectal and groin screening sites in a hospital-based multidrug-resistant organism (MDRO) surveillance program. Design: Prospective observational surveillance study. Setting: Tertiary academic hospital in Northern Greece. Patients: Hospitalized patients undergoing active MDRO screening based on predefined infection prevention and control criteria. Methods: A pathogen-focused analysis was conducted using data from a prospective MDRO surveillance program between October 2024 and January 2025. Screening swabs were obtained from the rectum and groin. Target organisms included multidrug-resistant (MDR) Klebsiella pneumoniae, Pseudomonas aeruginosa , vancomycin-resistant enterococci (VRE), Candida auris , and Acinetobacter spp. Pathogen-specific detection yields were calculated for each anatomical site. Results: Among 1,206 screening swabs, 308 (25.5%) were positive for at least one MDRO. Rectal swabs detected 95.8% of Klebsiella pneumoniae (K. pneumoniae) (92/96), 100% of VRE (59/59), and 66.7% of Pseudomonas aeruginosa (46/69). In contrast, 88.9% of Candida auris cases (24/27) were identified exclusively from groin swabs. Reliance on rectal screening alone would have missed nearly 90% of Candida auris carriers, whereas groin-only screening would have failed to detect most K. pneumoniae and all VRE carriers. Conclusions: Anatomical site selection critically influences MDRO surveillance sensitivity. Rectal screening is optimal for MDROs colonizing the gastrointestinal tract, whereas groin sampling is essential for detecting Candida auris . Pathogen-targeted, site-specific surveillance strategies may substantially improve detection efficiency and optimize infection prevention efforts in high-prevalence hospital settings.