Identification and functional characterization of secreted proteins by two species of Leptospira, one pathogenic and one saprophytic

• Grant number: 10/51215-9
• Support type: Regular Research Grants
• Duration: December 01, 2010 - November 30, 2012
• Field of knowledge: Biological Sciences - Microbiology
• Principal Investigator: Patricia Antonia Estima Abreu de Aniz
• Grantee: Patricia Antonia Estima Abreu de Aniz
• Home Institution: Instituto Butantan. Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil

Abstract

Leptospirosis is a zoonosis of worldwide distribution caused by pathogenic spirochetes of the genus Leptospira that colonize renal tubules of wild or domestic animals. Transmission occurs through the contact with water and soil contaminated with the urine from infected animals. The mechanisms by which leptospires invade the host and cause the disease are not fully understood, but experimental results have shown that the pathogenesis may be related to the ability of these bacteria to bind to extracellular matrix proteins, to escape host's immune responses and to produce toxins. Proteomic analyses of L. interrogans have confirmed the theoretical prediction of many proteins possibly involved in the host-pathogen interactions. Up to now, there are no published data of secreted proteins by leptospires identified using proteomic approaches, despite the existence of homolog genes in L. interrogans genome that to encode for some transport systems known in the other bacteria. In this context, this project aims to identify secreted proteins by Leptospira interrogans sorovar Pomona strain Fromm (pathogenic) and L. biflexa sorovar Patoc strain Patoc I (non-pathogenic) by proteomic analyses and to carry out assays of proteolytic activity using universal substrates. Identification and functional characterization of these proteins would further contribute to elucidation of the pathogenic mechanisms and development of novel strategies for the treatment and prevention of leptospirosis. (AU)