Whole-genome sequencing of Leptospira interrogans from southern Brazil: genetic features of a highly virulent strain

Sérgio Jorge, Frederico Schmitt Kremer, Natasha Rodrigues de Oliveira, Gabrielle de Oliveira Sanches Valerio Navarro, Amanda Munari Guimarães, Christian Domingues Sanchez, Rafael Danelon dos Santos Woloski, Karine Forster Ridieri, Vinícius Farias Campos, Luciano da Silva Pinto, Odir Antônio Dellagostin

BACKGROUND Leptospirosis is the most widespread zoonotic disease. It is caused by infection with pathogenic Leptospira species, of which over 300 serovars have been described. The accurate identification of the causative Leptospira spp. is required to ascertain the pathogenic status of the local isolates. OBJECTIVES This study aimed to obtain the complete genome sequence of a virulent Leptospira interrogans strain isolated from southern Brazil and to describe its genetic features. METHODS The whole genome was sequenced by next-generation sequencing (Ion Torrent). The genome was assembled, scaffolded, annotated, and manually reviewed. Mutations were identified based on a variant calling analysis using the genome of L. interrogans strain Fiocruz L1-130 as a reference. FINDINGS The entire genome had an average GC content of 35%. The variant calling analysis identified 119 single nucleotide polymorphisms (SNPs), from which 30 led to a missense mutation. The structural analyses identified potential evidence of genomic inversions, translocations, and deletions in both the chromosomes. MAIN CONCLUSIONS The genome properties provide comprehensive information about the local isolates of Leptospira spp., and thereby, could facilitate the identification of new targets for the development of diagnostic kits and vaccines.