Journal Article Ahead of print
PubMed: 42690043 DOI: 10.1093/femsle/fnag100
Comparative genomic analysis reveals distinct population structure in Legionella anisa.
FEMS Microbiol Lett
Authors: Maria Najeeb, Sara Matthews, Michele Prévost, Sebastien P Faucher
Affiliations
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada.
- Department of Civil, Geological, and Mining Engineering, Polytechnique de Montreal, Montreal, Quebec, Canada.
- Industrial Chair on Drinking Water, Department of Civil, Geological, and Mining Engineering, Polytechnique de Montreal, Montreal, Quebec, Canada.
- Centre de Recherche en Infectiologie Porcine et Avicole (CRIPA), Université de Montréal, Faculté de Médecine Vétérinaire, Saint-Hyacinthe, Québec, Canada.
- Centreau - Centre québécois de recherche sur la gestion de l'eau, Université Laval, Québec, Québec, Canada.
Abstract
Legionella anisa has been frequently isolated from engineered water systems; however, its population structure remains understudied compared to Legionella pneumophila. Here, we generated complete genome sequences for four L. anisa isolates recovered from a healthcare facility in Rimouski, Canada. Further the population structure of this species was investigated by performing comparative genomic analyses of the genomes generated in this study together with publicly available L. anisa genomes. Genome-wide phylogenetic analysis revealed the presence of three distinct clades separated by substantial genetic divergence (∼500 SNP), with the Rimouski isolates forming a tightly clustered group, suggesting a clonal lineage. Comparative pangenome analysis indicated moderate core genome conservation accompanied by a highly variable accessory genome (∼50%). The isolates characterized in this study harbored multiple plasmids encoding genes associated with conjugation, heavy metal resistance, and other stress-related functions, suggesting potential roles in environmental persistence. Previous studies have shown that L. anisa can proliferate within protozoan host cells, although outcomes vary depending on the host species. Our isolates showed efficient proliferation within Acanthamoeba castellanii, but not within Vermamoeba vermiformis, under the conditions tested. Together, these findings underscore the genomic diversity of this understudied Legionella species and provide a framework for future investigations regarding environmental persistence and potential pathogenicity.
MeSH
Legionella, Genome, Microbiology