Bacteriological Profile of Bacteremia and Antibiotic Resistance Patterns of the Isolated Pathogens

Background: Bacteremia is a diagnostic and therapeutic emergency. Understanding the predominant bacterial species responsible and their antibiotic susceptibility profiles is essential for guiding empirical antibiotic therapy. Methods: This study included both retrospective and prospective components conducted at the Benbadis University Hospital Center in Constantine from 2023 to 2024. It involved all hospitalized patients with at least one positive blood culture. Bacterial identification was performed using conventional methods and the Vitek 2 system. Antibiotic susceptibility testing was conducted via antibiogram following CLSI guidelines. Results: A total of 1,419 bacterial strains were isolated from 759 male and 660 female patients (sex ratio = 1.55), with adults representing the majority (71.6%). The most affected hospital departments were the neonatal unit (17.12%) and intensive care unit (16.27%). Coagulase-negative staphylococci accounted for the highest proportion (44.11%) of isolates. Among the most commonly identified pathogens were Klebsiella pneumoniae (10.77%), Staphylococcus aureus (8.74%), and Acinetobacter baumannii (5.78%). Klebsiella pneumoniae showed high resistance to third-generation cephalosporins (65.13%), gentamicin (60.52%), ciprofloxacin (77.94%), cotrimoxazole (70.39%), and imipenem (26.97%). A. baumannii exhibited alarmingly high resistance rates: 82.92% to carbapenems, 93.90% to third-generation cephalosporins, 90.24% to ciprofloxacin, and 90.91% to cotrimoxazole, though colistin remained effective. S. aureus showed 65.32% resistance to oxacillin, with no glycopeptide-resistant strains detected. Conclusion: Continuous epidemiological surveillance of bacteremia is critical at the hospital level to inform and optimize empirical antibiotic therapy for this severe condition.