Comprehensive genotyping and taxonomic analysis uncovers extensive distribution of intermediate Leptospira species in...

Leptospirosis, a globally prevalent zoonosis caused by pathogenic and intermediate Leptospira species, poses significant threats to public health and livestock industries. Despite its substantial impact, knowledge gaps persist regarding the prevalence and genetic diversity of Leptospira strains in many regions, including South America. This study aimed to characterize a diverse collection of Leptospira strains isolated from various sources in Colombia to enhance our understanding of the genetic diversity within this genus. Using a tiered approach combining conventional and genomic methods, we genotyped 55 isolates from various sources using 16S rRNA and rpoB gene sequencing, DNA ribotyping, and Multiple-Locus Variable-Number Tandem Repeat Analysis (MLVA). Most isolates were classified into phylogenetic groups containing pathogenic and intermediate strains of L. interrogans and L. wolffii, respectively, which was corroborated by ribotyping and MLVA. Whole-genome sequencing of selected strains revealed distinct genomic characteristics compared to related strains. Pan-genome analysis identified strain-specific genes, primarily hypothetical, while virulence factor analysis distinguished species-specific patterns. Furthermore, CRISPR-Cas system analysis uncovered genetic variations among the isolates. This study provides a framework for understanding Leptospira genetic diversity in Colombia and its potential implications on human and animal health. Our findings highlight the need for improved diagnostic methods and surveillance strategies that encompass both pathogenic and intermediate Leptospira species, which could significantly impact public health policies and veterinary practices in the region.