Banca de QUALIFICAÇÃO: ANGÉLICA LORENA PEREIRA MENDES CARIOCA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : ANGÉLICA LORENA PEREIRA MENDES CARIOCA
DATE: 29/11/2023
TIME: 14:00
LOCAL: Sala Virtual Remota https://bit.ly/Qualif_MSc_AngelicaCarioca_PGBIOEXP
TITLE:

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KEY WORDS:

nested–PCR, Borreliosis, Ehrliquiosis, Rondônia

PAGES: 68
BIG AREA: Ciências Biológicas
AREA: Biologia Geral
SUMMARY:

Ticks are obligatory ectoparasites of vertebrate animals, including humans. They belong to the Ixodid order, comprising more than 930 species in the world. There are three tick families: Ixodidae, Argasidae and Nutalliellidae. There are several agents transmitted by these arthropods among bacteria, protozoan and viruses: Rickettsia, Borrelia, Ehrlichia, Anaplasma, Babesia and Flaviviruses. In Brazil, only rickettsiae are known to cause illness to humans, however, there are lack of studies about other pathogens in this country, such as Borrelia and Ehrlichia, especially in the Amazon region, where there are a great number of anthropophilic tick species. The Borrelia genus may infect mammals and birds, and some species can cause Lyme disease. There are recent records of Borrelia-infected ticks in Brazil, but the occurrence of any human borreliosis still lack of evidence, although cases of a Lyme-like have been reported. The relapsing fever is a neglected disease, also provoked by Borrelia spirochaetes that are commonly found in argasid ticks from the Ornithodoros genus. Ehrlichia spp. are a genus of obligatory intracellular Gram-negative bacteria that infect human and animal phagocytes. Ehrlichia chaffeensis and Ehrlichia ewingii are etiological agents of, respectively, monocytic and granulocytic ehrlichiosis in North America. This study aimed to survey the incidence of Borrelia spp. and Ehrlichia spp. infecting free-living and parasitic ticks in the region of the Porto Velho Natural Park (PVNP), Rondônia state. The collection of free-living and wild animals parasitic ticks were performed within trails in the forest area of the PVNP, whereas the ticks collections from domestic animals (dogs and horses) were performed in private properties in the surrounding areas of the Park. After collected, the ticks were identified and submitted to DNA extraction and nested-PCR to search for borrelial Flab gene DNA, and semi nested-PCR targeting ehrlichial dsb gene DNA. The PCR products were visualized in a 1.5% agarose gel. A total of 153 free-living ticks were collected and the most abundant species were Amblyomma scalpturatum, followed by Amblyomma sp., A. naponense and A. calcaratum. Regarding the method of capture, 70% of the ticks were collected using a drag cloth, 18% were captured using a flag and 12% were captured by visual inspection. An infection rate of 4.6% of E. canis was found in R. linnaei. The infection rates of E. canis were 2% in Amblyomma scalpturatum and 1% in D. nitens. The positive samples were confirmed to the ehrlichial species by DNA sequencing. There were no Flab gene fragment detection in the tested ticks, suggesting that there were no borrelial infection in the ticks. Although ehrlichiae infection have been reported in horses, the present study reports E. canis in A. scalpturatum and D. nitens for the first time. The results of this study indicate that non-native pathogens may be introduced to the wild tick fauna in Brazil, and could help in a better understanding of the tick-pathogen-host relationships in the Western Amazon Region.

COMMITTEE MEMBERS:
Externo à Instituição - THIAGO FERNANDES MARTINS - USP
Externo à Instituição - FELIPE DA SILVA KRAWCZAK - UFG
Presidente - ***.335.462-** - SORAYA DOS SANTOS PEREIRA - UNIR