IMPAM   23988
INSTITUTO DE INVESTIGACIONES EN MICROBIOLOGIA Y PARASITOLOGIA MEDICA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
From typing to genomic epidemiology in Leptospira
Autor/es:
RUYBAL PAULA; VARNI VANINA; CAIMI KARINA
Lugar:
Amsterdam
Reunión:
Congreso; - II European Leptospirosis Society meeting on Leptospirosis and other rodent borne haemorrhagic fevers.; 2015
Institución organizadora:
European Leptospirosis Society
Resumen:
Leptospirosis is one of the most common and widespread zoonotic disease worldwide with nearly 900,000 people infected annually. The disease is caused by more than 250 different serovars (sv) of the genus Leptospira.  Earlier phylogenetic analyses have classified the genus into 3 distinct lineages that include pathogenic, intermediate and saprophytic species. The introduction of Multilocus Sequence typing (MLST) for strain identification provided the first sequence-based approach to strain resolution, and established the promise of unraveling the phylogeny of Leptospira, although in studies of limited strain panels or strains with restricted geographic prevalence. Regarding this, a pan-Leptospira genome project has provided data of very fine-scale resolution enabling the the study of the evolutionary history of this genus. For these reasons, the main objective of this study was to apply a 7 loci MLST scheme previously reassessed by our group to an extended group of strains of worldwide distribution which genome sequences are now available. A total of 403 strains were analyzed in this work. The collection includes strains from the Leptospira genome project and strains used in our previous work. All the sequences were analyzed by MLST 1.7 web application selecting Leptospira spp. #2 configuration which correspond to Leptospira R7L MLST scheme database. Allelic profiles and sequence types (STs) of genome sequences were assigned by MLSTest software. GoeBURST algorithm was applied to determine the relationships between STs. Intermediate species (L. licerasiae and L. fanei) that showed a complete hit in the genome sequences for all loci, were included in the subsequent analysis. The application of R7L scheme to the whole collection produced 199 different STs. GoeBURST analysis showed that the six pathogenic species are confined within 14 different clonal complexes (CC) and that there is no coexistence of different species within the same CC. We have also observed that the correlation among this larger set of isolates fits our previous observation, where founder genotypes contained isolates belonging to a single (or at most two) serogroup but not inversely.This work constitutes a starting point in the attempt to generate a deeper phylogenetic and epidemiological scenario of Leptospira genus.