Desenvolvimento de ferramentas para a manipulação genética e metodologias para a identificação de fatores de virulência de Leptospira spp

Abstract

In this study, Himar1 was used to obtain a total of 929 transposon mutants, of which, 721 correspond to coding sequences (CDS) disrupted by the transposon in 551 different genes. Some mutants were evaluated regarding the effect of gene disruption to virulence in the hamster model, and two attenuated mutants containing the transposon into hypothetical genes were identified. Another study aimed to develop a new genetic tool to help in the study of specific genes. Thus, an inducible expression system for L. biflexa was developed. Such inducible expression system employed as reporter genes the green fluorescence protein (gfp) and the gene encoding for the flagelin B protein (flaB). Fluorescent L. biflexa (GFP) and motile leptospires (FlaB) were observed after induction by IPTG. Finally, another study was conducted to determine, by PCR amplification, the presence of the lig genes in different pathogenic species. ligB appeared to be ubiquitously distributed, while ligA and ligC were detected only in a reduced number of serovars. In addition, a 214 bp specific ligB fragment was used to constitute a new method for pathogenic Leptospira species classification.