Browsing by Author "Bouyer, Donald H."

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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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    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.
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    Rickettsia in synanthropic and domestic animals and in their host from two areas of low endemicity for Brazilian spotted fever, in the eastern region of Minas Gerais state, Brazil.
    (2010) Milagres, Bruno Silva; Padilha, Amanda de Freitas; Gabriel G. Gomes; Montandon, Carlos Emmanuel; Pena, Dárlen Crísthiê Hermelinda; Bastos, Fernanda Aparecida Nieri; Silveira, Iara; Pacheco, Richard de Campos; Labruna, Marcelo Bahia; Bouyer, Donald H.; Freitas, Renata Nascimento de; Walker, David Hughes; Mafra, Cláudio Lísias; Galvão, Márcio Antônio Moreira
    The aim of this study was to understand the current epidemiology of rickettsial diseases in two rickettsialendemic regions in Brazil. In the municipalities of Pingo D’Agua and Santa Cruz do Escalvado, among serum samples obtained from horses and dogs, reactivity by immunofluorescent assay against spotted fever group rickettsiae was verified. In some serum samples from opossums ( Didelphis aurita ) captured in Santa Cruz do Escalvado, serologic response against rickettsiae was also verified. Polymerase chain reaction identified rickettsiae only in ticks and fleas obtained in Santa Cruz do Escalvado. Rickettsiae in samples had 100% sequence homology with Rickettsia felis . These results highlight the importance of marsupials in maintenance of the sylvatic cycle of rickettsial disease and potential integration with the domestic cycle. Our data also support the importance of horses and dogs as sentinels in monitoring circulation of rickettsiae in an urban area.