Detection and molecular characterization of Rickettsia in potential vectors from active focuses of spotted fever in the State of Rio de Janeiro

• Grant number: 10/03554-9
• Support type: Scholarships in Brazil - Master
• Effective date (Start): September 01, 2010
• Effective date (End): February 29, 2012
• Field of knowledge: Biological Sciences - Parasitology - Entomology and Malacology of Parasites and Vectors
• Principal researcher: Teresinha Tizu Sato Schumaker
• Grantee: Nicole Oliveira de Moura
• Home Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Brazilian Spotted Fever (BSF) caused by rickettsiae of the spotted fever group (SFGR) and transmitted by ticks, re-emerged in the country, mainly in the Southeast. Hundreds of suspected human cases, including deaths, have been reported. Molecular researches indicate that at least three pathogenic species of SFGR, carried by fleas or ticks, circulate in ecotopes of the States of Sao Paulo and Minas Gerais, besides others with unknown pathogenicity. In the State of Rio de Janeiro, which has a high population density and huge tourist flow, the lethality of BSF is high, but only recently laboratory and field investigations began in some locations and the results indicated the involvement of new species of ectoparasites in the disease's epidemiology. This project aims evaluate the occurrence of rickettsiae in ectoparasites of domestic animals living in areas of BSF human cases, suspected, compatible or confirmed in different municipalities of Rio de Janeiro State in recent active focuses. Specifically, we aim to: a) detect of rickettsiae genes in possible vectors, ticks and fleas collected on domestic and domesticated animals, and also free in the environment; b) analyse of the minimum frequency of infected ectoparasites and; c) identify, by molecular methods, the Rickettsia species detected in analyzed ectoparasites. The samples were collected between 2007-2009, in locations that lack of information about maintaining the transmission cycle of Rickettsiae: Noroeste fluminense (Porciúncula and Itaperuna), Serrana (Trajano de Morais and São José do Vale do Rio Preto) and Sul Fluminense (Piraí and Barra do Piraí). The identified ectoparasites will be processed individually or in groups, according to sex, stage of development and degree of engorgement. The samples DNAg will be extracted and submitted to the genes research of: organisms of the genus Rickettsia (gltA) and Spotted Fever Group rickettsiae (OmpA) by polymerase chain reaction (PCR). The amplified fragments will be cloned and the nucleotide sequences will be analyzed. The frequencies of infected vectors will be calculated by species and investigated focus. Other active focuses reported in the course of the project may be added to the search. The information obtained will be useful to adopt specific strategies for the control and prevention of BSF, supporting basic health care.

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

MOURA, Nicole Oliveira de. Detecção e caracterização molecular de riquétsias em potenciais vetores procedentes de focos ativos de febre maculosa do Estado do Rio de Janeiro.. 2012. Master's Dissertation - Universidade de São Paulo (USP). Instituto de Ciências Biomédicas São Paulo.