Characterization and Antimicrobial Susceptibility Patterns of Enterococcus Species Isolated from Nosocomial Infections in a Saudi Tertiary Care Hospital over a Ten-Year Period (2012–2021)

Abstract

Introduction: The Enterococcus genus is a common cause of nosocomial infections, with vancomycin-resistant enterococci (VRE) posing a significant treatment challenge. Method: This retrospective study, spanning ten years (2012 to 2021), analyzes antimicrobial susceptibility patterns of Enterococcus species from clinical samples in a Saudi Arabian tertiary care hospital. Result: A total of 1034 Enterococcus isolates were collected, 729 from general wards and 305 from intensive care unit (ICU) patients. VRE accounted for 15.9% of isolates. E. faecalis was the most common species (54.3% of isolates and 2.7% of VRE), followed by E. faecium (33.6% of isolates and 41.2% of VRE). E. faecium exhibited the highest resistance to ciprofloxacin (84.1%), ampicillin (81.6%), and rifampicin (80%), with daptomycin (0.6%) and linezolid (3.1%) showing the lowest resistance. In E. faecalis, ciprofloxacin resistance was highest (59.7%), followed by rifampicin (20.1%) and ampicillin (11.8%). Daptomycin (0%), linezolid (1.5%), and vancomycin (2.7%) had the lowest resistance. VRE cases had higher mortality rates compared to vancomycin-sensitive enterococci (VSE). Conclusion: Eight different strains of Enterocci were identified. E. faecalis was the most commonly identified strain, while E. faecium had the highest percentage of VRE. VRE cases had a significantly higher mortality rate than VSE cases.