Browsing by Author "Oliveira, Karla Andrade de"

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    Amblyomma imitator ticks as vectors of Rickettsia rickettsii, Mexico.
    (2010) Oliveira, Karla Andrade de; Pinter, Adriano; Medina Sanchez, Aaron; Boppana, Venkata D.; Wikel, Stephen Kenneth; Saito, Tais B.; Shelite, Thomas; Blanton, Lucas; Popov, Vsevolod; Teel, Pete D.; Walker, David Hughes; Galvão, Márcio Antônio Moreira; Mafra, Cláudio Lísias; Bouyer, Donald H.
    Rickettsia rickettsii is a gram-negative, obligate, intracellular bacterium and the cause of Rocky Mountain spotted fever (RMSF). In Mexico, its transmission has been attributed to Rhipicephalus sanguineus and Amblyomma cajennense ticks. Amblyomma imitator has close affi nity with A. cajennense and was formerly confused with this species. These ticks’ distributional range extends from southern Texas, southward through Mexico (where they are widely sympatric with A. cajennense ticks) into Central America (1). In this study, we isolated and characterized R. rickettsii from A. imitator from Mexico by using molecular methods.
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    Effect of ionizing radiation exposure on Trypanosoma cruzi ubiquitin-proteasome system.
    (2017) Cerqueira, Paula Gonçalves; Silva, Danielle Gomes Passos; Rocha, João Pedro Vieira da; Mendes, Isabela Cecilia; Oliveira, Karla Andrade de; Oliveira, Camila Franco Batista de; Vilela, Liza Figueiredo Felicori; Nagem, Ronaldo Alves Pinto; Cardoso, Josiane; Nardelli, Sheila Cristina; Krieger, Marco Aurélio; Franco, Glória Regina; Macedo, Andréa Mara; Pena, Sérgio Danilo Junho; Schenkman, Sérgio; Gomes, Dawidson Assis; Cota, Renata Guerra de Sá; Machado, Carlos Renato
    tIn recent years, proteasome involvement in the damage response induced by ionizing radiation (IR)became evident. However, whether proteasome plays a direct or indirect role in IR-induced damageresponse still unclear. Trypanosoma cruzi is a human parasite capable of remarkable high tolerance toIR, suggesting a highly efficient damage response system. Here, we investigate the role of T. cruzi pro-teasome in the damage response induced by IR. We exposed epimastigotes to high doses of gamma rayand we analyzed the expression and subcellular localization of several components of the ubiquitin-proteasome system. We show that proteasome inhibition increases IR-induced cell growth arrest andproteasome-mediated proteolysis is altered after parasite exposure. We observed nuclear accumulationof 19S and 20S proteasome subunits in response to IR treatments. Intriguingly, the dynamic of 19S par-ticle nuclear accumulation was more similar to the dynamic observed for Rad51 nuclear translocationthan the observed for 20S. In the other hand, 20S increase and nuclear translocation could be relatedwith an increase of its regulator PA26 and high levels of proteasome-mediated proteolysis in vitro. Theintersection between the opposed peaks of 19S and 20S protein levels was marked by nuclear accumu-lation of both 20S and 19S together with Ubiquitin, suggesting a role of ubiquitin-proteasome system inthe nuclear protein turnover at the time. Our results revealed the importance of proteasome-mediatedproteolysis in T. cruzi IR-induced damage response suggesting that proteasome is also involved in T. cruziIR tolerance. Moreover, our data support the possible direct/signaling role of 19S in DNA damage repair.Based on these results, we speculate that spatial and temporal differences between the 19S particle and20S proteasome controls proteasome multiple roles in IR damage response.
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    First report of Ehrlichia ewingii detected by molecular investigation in dogs from Brazil.
    (2009) Oliveira, Luciana Souza de; Oliveira, Karla Andrade de; Pescatore, A. M.; Lamëgo, Márcia Rogéria de Almeida; Conceição, Lissandro Gonçalves; Galvão, Márcio Antônio Moreira; Siqueira, Cláudio Lísias Mafra de
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    Molecular identification of Rickettsia felis in ticks and fleas from an endemic area for Brazilian Spotted Fever.
    (2008) Oliveira, Karla Andrade de; Oliveira, Luciana Souza de; Dias, C. C. A.; Silva Júnior, Abelardo; Lamëgo, Márcia Rogéria de Almeida; Amalda, G.; Bouyer, Donald H.; Galvão, Márcio Antônio Moreira; Siqueira, Cláudio Lísias Mafra de
    Rickettsioses are arthropod-borne diseases caused by parasites from the Order Rickettsiales. The most prevalent rickettsial disease in Brazil is Brazilian Spotted Fever (BSF). This work intends the molecular detection of those agents in ectoparasites from an endemic area of BSF in the state of Espírito Santo. A total of 502 ectoparasites, among them Amblyomma cajennense, Amblyomma dubitatum (A. cooperi), Riphicephalus sanguineus, Anocentor nitens and Ctenocephalides felis, was collected from domestic animals and the environment and separated in 152 lots according to the origin. Rickettsia sp. was detected in pools of all collected species by amplification of 17kDa pro¬tein-encoding gene fragments. The products of PCR amplification of three samples were sequenced, and Rickettsia felis was identified in R. sanguineus and C. felis. These results confirm the presence of Rickettsia felis in areas previ¬ously known as endemic for BSF, disease caused by Rickettsia rickettsii. Moreover, they show the needing of further studies for deeper knowledge of R. felis-spotted fever epidemiology and differentiation of these diseases in Brazil.