National Landscape of Antimicrobial Resistance in the Philippines: A Systematic Review of Surveillance and Clinical Data

Abstract

Background: Antimicrobial resistance (AMR) is an escalating global public health threat that reduces the effectiveness of antimicrobial therapies and contributes to increased morbidity, mortality, and healthcare costs. In the Philippines, rising antibiotic consumption, self-medication, and inconsistent antimicrobial stewardship practices have accelerated the emergence of resistant pathogens. However, existing evidence remains fragmented across surveillance reports and clinical studies, limiting a comprehensive understanding of national resistance patterns. Methods: This study employed a systematic review design in accordance with PRISMA 2020 guidelines and was registered in the PROSPERO database (CRD420261360657). A comprehensive literature search was conducted using PubMed/MEDLINE, Scopus, and Web of Science, supplemented by national surveillance reports. Studies published from January 2008 to April 2026 reporting antimicrobial resistance data from human clinical isolates in the Philippines were included. Eligible studies were screened based on predefined criteria, and data were extracted and synthesized using a narrative descriptive approach. Results: A total of 14 studies met the inclusion criteria. Findings consistently identified Gram-negative pathogens, particularly Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa, as the primary contributors to antimicrobial resistance. High resistance rates to critical antibiotics, including carbapenems and third-generation cephalosporins, were observed, with Acinetobacter baumannii demonstrating resistance levels of up to 56%. Increasing resistance trends were noted following the COVID-19 pandemic, alongside strong associations between antimicrobial consumption and resistance patterns. Molecular evidence revealed the role of clonal dissemination and horizontal gene transfer, with key resistance genes such as blaNDM (gene encoding New Delhi metallo-β-lactamase, an enzyme that confers resistance to carbapenem antibiotics) and blaOXA (gene encoding OXA-type β-lactamase enzymes, which confer resistance to β-lactam antibiotics, including carbapenems in some variants) identified. AMR was associated with substantial clinical burden, including mortality rates of up to 60% in severe infections. Conclusion: Antimicrobial resistance in the Philippines is a growing and significant public health concern predominantly driven by multidrug-resistant Gram-negative pathogens. Strengthening antimicrobial stewardship, enhancing surveillance systems, and reinforcing infection prevention and control measures are essential to mitigate the increasing burden of AMR.