An Antimicrobial susceptibility study to compare the in vitro activity of antimicrobial agents in the Philippines against Enterobacterales and Pseudomonas aeruginosa from different infection sites: results from ATLAS surveillance program (2018–2021)

BACKGROUND: This antimicrobial surveillance study reports the in vitro antimicrobial activity and susceptibility data of various antimicrobials against Enterobacterales and Pseudomonas aeruginosa isolates in the Philippines. METHODS: Isolates were collected from three clinical sites in the Philippines between 2018 and 2021, as part of the Antimicrobial Testing Leadership and Surveillance (ATLAS) program. A central laboratory (International Health Management Associates, Inc.) performed antimicrobial susceptibility testing using broth microdilution methodology according to Clinical Laboratory Standards Institute (CLSI) guidelines. Minimum inhibitory concentrations (MICs) were interpreted using the CLSI (2023) breakpoints. RESULTS: A total of 1503 isolates were collected in the ATLAS program from 2018 to 2021. The top three pathogens throughout the study period were Pseudomonas aeruginosa (30.8%), Klebsiella pneumoniae (24.1%), and Escherichia coli (20.8%). Based on the CLSI (2023) breakpoints, isolates of Enterobacterales were highly susceptible to amikacin (98.6%), tigecycline (96.9%) and ceftazidime-avibactam (95.9%), while P. aeruginosa isolates were most susceptible to amikacin (96.5%), ceftazidime-avibactam (94.0%) and ceftolozane-tazobactam (92.7%). CONCLUSION: The present ATLAS study provides essential insights on the prevalence and susceptibility patterns of Enterobacterales and P. aeruginosa isolates in the Philippines. Ceftazidime-avibactam is a valuable and effective treatment option due to its potent activity against Enterobacterales and P. aeruginosa. Continuous surveillance is important in improving antimicrobial stewardship and antibiotic prescriptions in the country.