Pathogenicity studies of environmental Legionella pneumophila Isolates in Ningbo
Legionella pneumophila is an opportunistic pathogen ubiquitously present in aquatic environments. Environmental isolates exhibit considerable variability in pathogenic potential, with highly virulent strains posing a significant public health risk due to their capacity to cause severe pneumonia. Conventional monitoring approaches are limited to detecting the presence and concentration of L. pneumophila in environmental samples and cannot assess strain-level pathogenicity, often leading to overly conservative disinfection practices and unnecessary economic costs. In this study, we isolated 58 environmental L. pneumophila strains from urban water systems across different years, among which 33 were assigned to sequence type 1 (ST1) and 9 to ST583. We combined whole-genome sequencing with ML to predict the pathogenicity of L. pneumophila isolates from urban water environments, integrating 58 locally isolated strains with 1,002 high-quality genomes from public databases.This study will offers a scientific basis for risk stratified disinfection, potentially reducing unnecessary overtreatment and focusing public health resources on the most dangerous environmental reservoirs.