The Use of the WHO AWaRe Tool to Optimize Antibiotic Selection after Surgery

Background: Antibiotic resistance is a global health problem that needs urgent attention. WHO introduced AWaRe (Access, Watch, Reserve) classification of antibiotics to help in optimizing antibiotic use. Objective: This study aimed to evaluate the efficacy of the WHO AWaRe classification in guiding antibiotic selection and optimizing treatment outcomes for pathogens isolated from post-surgical patients at Mansoura University Hospitals. Methodology: A retrospective analysis was conducted on microbiological cultures obtained from post-surgical patients between January 2022 and December 2023. Samples included blood, urine, sputum, wound swabs, surgical drains, and aspirates. Automated identification of isolates was performed using the Vitek 2 system, while antibiotic susceptibility was assessed using the Kirby-Bauer disk diffusion method and Vitek 2. Antibiotics were categorized according to the WHO AWaRe classification. Results: Out of 1159 cultures, 401 (34.6%) were positive, with Gram-negative bacteria accounting for 73.6% of isolated organisms and Gram-positive bacteria for 26.4%. Escherichia coli (34%) and Klebsiella spp. (20%) were the predominant Gram-negative organisms, while Staphylococcus aureus and coagulase-negative staphylococci represented 19% of total isolates. Antibiotic susceptibility testing revealed variable resistance patterns, with carbapenems showing high efficacy against Enterobacter cloacae and E. coli but reduced activity against Acinetobacter baumannii. Aminoglycosides and Piperacillin/Tazobactam were effective against most isolates, while resistance to β-lactams and fluoroquinolones was prominent. Conclusions: The WHO AWaRe classification is a valuable framework for optimizing antibiotic selection in post-surgical infections. The study highlights the predominance of Gram-negative bacteria and their resistance patterns, emphasizing the need for targeted antibiotic stewardship to preserve the efficacy of critical antibiotics.