Antimicrobial susceptibility of Legionella gormanii: species-specific ECOFFs, distinct MICs for rifampin versus Legionella pneumophila

This study establishes the first large-scale susceptibility dataset and species-specific ECOFFs for L. gormanii. The findings highlight key inter-species differences in susceptibility, particularly for rifampin, underscoring that treatment paradigms cannot be safely extrapolated from L. pneumophila. These ECOFFs provide a critical tool for surveillance of non-wild-type resistance. However, these data, derived from environmental isolates, are intended for epidemiological and hypothesis-generating purposes and must be supplemented with clinical and pharmacokinetic/pharmacodynamic (PK/PD) studies before informing changes to clinical practice.