See and Sequence: Integrating Whole-Genome Sequencing Within the National Antimicrobial Resistance Surveillance Program in the Philippines

Drug-resistant bacterial infections constitute a growing threat to public health globally. National networks of laboratory-based surveillance of antimicrobial resistance (AMR) monitor the emergence and spread of resistance and are central to the dissemination of these data to AMR stakeholders. Whole-genome sequencing (WGS) can support these efforts by pinpointing resistance mechanisms and uncovering transmission patterns. We implemented WGS within the established Antimicrobial Resistance Surveillance Program (ARSP) of the Philippines. We aimed to employ WGS to characterize bacterial populations and dissect resistance phenotypes of key bug-drug combinations, thus establishing a genetic background to contextualize local prospective surveillance. We sequenced the genomes from eight bacterial pathogens collected between 2013 and 2014 by the ARSP, and conducted phylogenetic analyses, in silico genotyping, genomic predictions of AMR, and characterization of key plasmids carrying carbapenemase genes. Here, we focus on carbapenemase-producing organisms. ARSP phenotypic data indicated increasing carbapenem resistance for Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae and Escherichia coli, with marked expansion of specific resistance phenotypes. By linking resistance phenotypes to genomic data, we revealed the diversity of genetic lineages (strains), AMR mechanisms, and AMR vehicles underlying this expansion. We discovered a previously unidentified plasmid-driven hospital outbreak of carbapenem-resistant K. pneumoniae, uncovered the interplay of carbapenem resistance genes and plasmids in the geographic circulation of international epidemic K. pneumoniae ST147, and found that carbapenem-resistant E. coli ST410 were represented by diverse lineages of global circulation that both conserved international plasmids and acquired plasmids of local circulation. WGS provided an enhanced understanding of the interplay between strains, genes and vehicles driving the dissemination of carbapenem resistance in the Philippines. We generated a blueprint for the integration of WGS and genomic epidemiology into an established national system of laboratory-based surveillance of AMR through international collaboration. Continued prospective sequencing, capacity building and collaboration will strengthen genomic surveillance of AMR in the Philippines and the translation of genomic data into public-health action.