In-vitro Comparison of the Minimum Inhibitory Concentrations of Different Antimicrobials against Enterococcal Isolates in Cairo University Hospitals using the Vitek-2 Compact System

Background: Enterococci were the first among the ESKAPE pathogens (Enterococcus spp., Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter spp.) to be recognized by the WHO as emerging causes of nosocomial and antibiotic-resistant infections, posing a growing public health threat in recent decades. Objective: was to determine the minimum inhibitory concentrations of different antimicrobials against enterococcal isolates in Cairo University Hospitals using the VITEK ® 2 compact system. Methodology: A total of 50 Enterococcus isolates were selected for testing. All isolates were obtained from specimens submitted between 2019 and 2021 to Cairo University Hospital’s main Microbiology laboratory. Isolates were isolated from different sources, including blood, urine, wounds, pus, and pleural fluid. Species identification and minimum Inhibitory Concentration (MIC) for different antibiotics were done using the VITEK® 2 compact system. Results: Enterococcus faecalis was the most prevalent enterococcal species isolated (54%), followed by E. faecium (38%), E. gallinarum (4%), and E. avium (4%). Out of 19 patients who utilized medical devices, 11 (57.9%) had Enterococcus faecium infections (p-value= 0.036). Tigecycline antibiotic showed the best susceptibility (100%) against Enterococcus species, followed by vancomycin (80.8%), and linezolid (78.9%). High resistance rates were detected against streptomycin (68.1%), ciprofloxacin (57.4%), levofloxacin (55.4%), and gentamycin high dose (51%).