Long-term antimicrobial trends in people living with chronic lung disease: An AMR-Lung ERS clinical research collaborative proof-of-concept study

<bold>Background:</bold> In this study, AMR-LUNG (an ERS clinical research collaborative) explored the ability of routinely collected antibiotic susceptibility testing (AST) to map AMR dynamics in people living with chronic lung disease. <bold>Methods:</bold> Retrospective analysis of AST results in sputum samples in two large respiratory services in the UK (Adult CF centre and a community respiratory service). Data were available for 2017-2023. <bold>Results:</bold> Data were available for 17,821 sputum samples positive for <italic>P. aeruginosa</italic>, <italic>H. influenzae</italic> or <italic>M. catarrhalis</italic>. Overall antibiotic resistance dynamics were divergent between pathogens, Fig 1. For example, <italic>M. catarrhalis</italic> resistance was stable (Fig 1B), whereas <italic>H. influenzae</italic> resistance to amoxicillin-clavulanic acid increased between 2017 and 2023 (Fig 1D). For <italic>P. aeruginosa</italic>, resistance was generally increasing in people living with CF (Fig 1A) but was stable those with bronchiectasis or COPD (Fig 1C) (MAR index 0.33 to 0.43 and 0.09 to 0.08 respectively for 2018-22) <bold>Conclusion:</bold> We identified distinct AMR trajectories associated with different pathogens in people living with CF, bronchiectasis and COPD. These data provide proof-of-concept for readily available microbiology data-sources to provide informative longitudinal resistance trends in key respiratory pathogens. This approach could provide the basis for international mapping of respiratory-relevant AMR. <fig><object-id>erj;64/suppl_68/PA4193/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>