De-escalation of antibiotic therapy represents a fundamental pillar of antimicrobial stewardship efforts designed to limit the emergence and spread of drug resistance. The present research was carried out to determine how positive culture and sensitivity findings for Escherichia coli or Methicillin-sensitive Staphylococcus aureus (MSSA) influence the de-escalation of prescribed antibiotics. A total of 256 patients with confirmed infections were included in this prospective observational investigation. Clinical specimens were largely obtained from purulent material at infection sites for microbial identification and subsequent susceptibility profiling. Patient-level data were retrieved from medical charts and included demographic characteristics, specimen origin, the pathogen identified, and whether the antimicrobial regimen was initiated empirically or tailored definitively according to culture results. Data processing was performed with SPSS. Of the 256 recovered microorganisms, 138 (53.9%) were MSSA and 118 (46.1%) were E. coli. MSSA isolates displayed complete (100%) susceptibility to cefoxitin, oxacillin, vancomycin, fosfomycin, and colistin, and greater than 90% susceptibility to linezolid (95.3%), tigecycline (93.1%), chloramphenicol (92.2%), and amikacin (90.2%). E. coli strains were fully susceptible only to fosfomycin, with susceptibility levels exceeding 90% for colistin (96.7%), polymyxin-B (95.1%), and tigecycline (92.9%). Empiric therapy was characterized by frequent administration of cefoperazone+sulbactam (151), amikacin (149), ceftriaxone (33), metronidazole (30), and piperacillin+tazobactam (22). Once susceptibility data became available, the antibiotics most commonly selected for E. coli included intravenous meropenem (34), amikacin (34), ciprofloxacin (29), and cefoperazone+sulbactam (25). For MSSA infections, linezolid (48), clindamycin (30), intravenous cefoperazone+sulbactam (16), and amikacin (15) were frequently prescribed. Overall, antibiotic consumption fell by 23% among E. coli cases and by 43% in the MSSA group. Access to culture-sensitivity data enabled antimicrobial de-escalation, particularly reducing reliance on broad-spectrum agents. Hence, individual hospitals should formulate local guidance rooted in facility-specific antimicrobial susceptibility trends while curtailing unwarranted empiric use of broad-spectrum antibiotics.
