Banca de DEFESA: RUTH FLÁVIA BARROS SETÚBAL

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : RUTH FLÁVIA BARROS SETÚBAL
DATE: 29/09/2023
TIME: 10:00
LOCAL: Google Meet, https://meet.google.com/goj-foht-oux
TITLE:

Phylogenetic analysis of rfb locus genes of the Leptospira genus of the Sejroe, Mini and Hebdomadis serogroups

KEY WORDS:

Leptospirosis; rfb locus; Lipopolysaccharides; serological classification;

PAGES: 21
BIG AREA: Ciências Biológicas
AREA: Parasitologia
SUMMARY:

Leptospirosis is a zoonosis with a major impact on public health, as it is considered a notifiable disease and occurs mainly in tropical regions with poor sanitation and vulnerable socio-economic conditions. It is caused by bacteria of the genus Leptospira and phylum Spirochaetes and contamination occurs through direct or indirect contact with the contaminating agent. In addition to taxonomic classification, which is carried out through sequencing and the analysis of some marker genes, such as 16S rRNA and secY, they are usually classified based on their antigenic characteristics into serogroups and serovars. This type of classification is widely used in epidemiological studies and vaccine development. Despite its importance, few studies have been carried out to understand the evolutionary dynamics of the emergence or change of serology in this genus. In view of this, in this study we applied molecular phylogeny methods in order to understand the evolutionary processes involving the genus' serology. To this end, gene sequences that are part of the rfb locus from samples of the Sejroe, Mini and Hebdomadis serogroups (34 samples) were extracted and submitted to the phylogenetic pipeline, resulting in the inference of 75 maximum likelihood trees. Analyzing the trees, it can be seen that those genes from the rfb locus found in the majority of Leptospira species presented a topology similar to that of the species tree. On the other hand, those genes found in the variable region of the locus showed trees with topologies that suggest the occurrence of lateral transfer between the species L. borgpetersenii and L. kirschneri and L. interrogans and L. weilli. The study suggests a new interpretation of the evolutionary history of the rfb locus genes and the evolutionary dynamics of serogroup changes.

COMMITTEE MEMBERS:
Presidente - 2170415 - Jorge Estefano de Santana Souza
Externa à Instituição - Maria Raquel Venturim Cosate
Interno - 3063244 - TETSU SAKAMOTO