A Modern Framework for Identifying Novel Environmental Legionella Species
Artikel i vetenskaplig tidskrift, 2026
Accurate species-level identification of Legionella during routine environmental surveillance remains challenging, as standard proteomic screening methods like MALDI-TOF MS often lack the resolution to distinguish closely related taxa. This study introduces a novel, cost-effective, and stepwise taxonomic framework that bridges routine environmental monitoring with multi-layered, genome-resolved analysis. We expanded upon our previous screening of four novel candidate lineages by focusing on the three remaining, uncharacterized environmental isolates, while using the recently validly described Legionella sheltonii (strain PATHC038) as a reference framework control. By applying nucleotide- and protein-based overall genomic relatedness indices (ANI, dDDH, AAI, and POCP) alongside core-genome phylogenomics, our framework independently confirmed the genomic distinctiveness of the three isolates, which exhibited AAI values of 94.3–96.6% and POCP values of 86.5–91.0%, with POCP values lying close to the proposed species delineation threshold. By defining clear criteria for escalating isolates from culture to targeted sequencing, this workflow prevents diagnostic misidentification during epidemiological outbreak investigations and provides public health agencies with a scalable tool to monitor hidden Legionella diversity, ultimately enhancing proactive water safety and risk assessment.
percentage of conserved proteins (POCP)
novel Legionella species
phylogenomics
whole genome sequencing
average amino acid identity (AAI)
Författare
Karla Vasari
PathCon Laboratories
University of Rijeka
Maja Kovačević
Sveučilište u Zagrebu
PathCon Laboratories
Niko Kasalo
Ruder Boskovic Institute
Snjezana Kazazic
Ruder Boskovic Institute
Ivan Mijakovic
Danmarks Tekniske Universitet (DTU)
Chalmers, Life sciences, Systembiologi
Goran Klobucar
Sveučilište u Zagrebu
D. Franjevic
Sveučilište u Zagrebu
Josip Skejo
Sveučilište u Zagrebu
Tomislav Domazet-Lošo
Ruder Boskovic Institute
Catholic University of Croatia
Brian G. Shelton
PathCon Laboratories
Marina Santic
Ruder Boskovic Institute
University of Rijeka
Roberta Sauerborn Klobucar
PathCon Laboratories
Life
0024-3019 (ISSN) 2075-1729 (eISSN)
Vol. 16 7 1187Ämneskategorier (SSIF 2025)
Mikrobiologi inom det medicinska området
DOI
10.3390/life16071187
PubMed
42514254