Brazilian spotted fever: A reemergent zoonosis

Brazilian spotted fever is caused by the bacterium Rickettsia rickettsii, which is the most pathogenic species of the spotted-fever rickettsiae group and is transmitted by the bite of infected ticks. Amblyomma cajennense is the most important tick species involved in the cycle of this zoonosis in Brazil as it presents low host specificity, great number of natural reservoirs and wide geographic distribution. It was first described in the state of São Paulo in 1929 and later in Rio de Janeiro, Minas Gerais and Bahia. The number of cases decreased in the 1940's with the development of new plague control techniques and antibiotics. In the last decades, the number of new cases has increased. The current review aimed at reporting some of the epidemiological and public health aspects of this reemergent disease with new foci, mainly in the southeastern region of Brazil.

Acaricidal activity of ethanolic extract from aerial parts of Tagetes patula L. (Asteraceae) against larvae and engorged adult females of Rhipicephalus sanguineus (Latreille, 1806)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Report on ticks collected in the Southeast and Mid-West regions of Brazil: analyzing the potential transmission of tick-borne pathogens to man

Foram coletados espécimes de carrapatos em 1993, 1996, 1997, e 1998, principalmente de animais selvagens e domésticos, nas Regiões Sudeste e Centro-oeste do Brasil. Nove espécies de Amblyommidae foram identificadas: Anocentor Nitens, Amblyomma cajennense, Amblyomma ovale, Amblyomma fulvum, Amblyomma striatum, Amblyomma rotundatum, Boophilus microplus, Boophilus annulatus e Rhipicephalus sanguineus. Analisou-se o potencial destas nove espécies de carrapatos como transmissores de patógenos para o homem. Um Flaviviridade Flavivirus foi isolado de espécimes de Amblyomma cajennense coletados de um capivara doente (Hydrochaeris hydrochaeris). Amblyomma cajennense é o transmissor principal da Rickettsia rickettsii (=R. rickettsi), o agente causador da febre maculosa no Brasil. Os mamíferos selvagens, principalmente capivaras e veados infestados por carrapatos vivem em próximo contato com gado, cavalos e cachorros, com quem compartilham os mesmos carrapatos, oferecendo risco de transmissão destas zoonoses silvestres aos animais domésticos e ao homem.

Surveillance for zoonotic vector-borne infections using sick dogs from southeastern Brazil

For many vector-borne organisms, dogs can be used as sentinels to estimate the risk of human infection. The objective of this study was to use dogs as sentinels for multiple vector-borne organisms in order to evaluate the potential for human infection with these agents in southeastern Brazil. Blood from 198 sick dogs with clinicopathological abnormalities consistent with tick-borne infections were selected at the São Paulo State University Veterinary Teaching Hospital in Botucatu and tested for DNA and/or antibodies against specific vector-borne pathogens. At least one organism was detected in 88% of the dogs, and Ehrlichia canis DNA was amplified from 78% of the blood samples. Bartonella spp. seroreactivity was found in 3.6%. Leishmania chagasi antibodies were detected in 1% of the dogs. There was no serological or polymerase chain reaction evidence of infection with Anaplasma phagocytophilum, Borrelia burgdorferi, Ehrlichia chaffeensis, Ehrlichia ewingii, and Rickettsia rickettsii. The full E. canis 16S rRNA gene sequence of one of the Brazilian strains obtained in this study was identical to the causative agent of human ehrlichiosis in Venezuela. Ehrlichia canis may pose a human health hazard and may be undiagnosed in southeastern Brazil, whereas exposure to the other organisms examined in this study is presumably infrequent.

Innate Immunity in Wooless Lamb to Larvae of Amblyomma cajennense Tick (Fabricius, 1787) (Acari: Ixodidae)

P>The Cayenne tick Amblyomma cajennense infests preferably horses in its adult form but other mammal species in its immature stages and is the main vector of Rickettsia rickettsii, the Brazilian spotted fever pathogen. As wooless lambs are often raised on pasture together with horses, an experiment was performed to investigate their possible acquisition of resistance to A. cajennense after experimental infestations. Seven naive wooless lambs were infested thrice at 60 days interval with immature and adult instars of A. cajennense from a laboratory colony, the tick biotic potential being determined and biopsies of tick bite lesions taken to investigate the inflammatory cell component. Nearly 100% of larvae died in all infestations, while nymphs and adults fed normally throughout re-infestations. Microscopic features of adult tick bite lesions revealed predominance of neutrophils (38%) and eosinophils (36.8%), respectively, in the first and second infestations. In the third infestation, 43.6% of MN cells were found and about 31% of eosinophils. on the other hand, nymph bite lesions revealed in all infestations a predominance of eosinophils, increasing from 36% in the first infestation to 50.5% in the third one. It is concluded that wooless lambs present remarkable innate resistance against larvae of A. cajennense, but marked susceptibility to the other tick instars despite the migration of great number of eosinophils to the tick lesion.

Ticks (Acari: Ixodidae) within various phytophysiognomies of a Cerrado reserve in UberlA cent ndia, Minas Gerais, Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Chemical characterization and acaricide potential of essential oil from aerial parts of Tagetes patula L. (Asteraceae) against engorged adult females of Rhipicephalus sanguineus (Latreille, 1806)

Rhipicephalus sanguineus, commonly known as the brown dog tick, is one of the most widely distributed species of tick. In dogs, it can cause anemia and provide the transmission of pathogenic microorganisms such as Babesia canis, Ehrlichia canis, Hepatozoon canis, Anaplasma platys, and Mycoplasma haemocanis. To man, it can transmit the intracellular parasites Rickettsia rickettsii and Rickettsia conorii, the causative agents of the Rocky Mountain spotted fever in the Americas and Mediterranean and spotted fever in Europe and North Africa. Its control is performed by applying synthetic formulations composed of pyrethroids; however, continued use of these products results in environmental damage and acquisition of resistance. Alternatively, studies with botanical insecticides have been increasingly recurrent. Therefore, this study aimed to test the efficacy of essential oil of Tagetes patula, a ruderal species widely described in the literature for its insecticidal properties, in engorged females of R. sanguineus by the adults immersion test (AIT) and impregnated paper disk test (IPDT). The essential oil used, through gas chromatography coupled to mass spectrometry, revealed the presence of 55 compounds, being the 4-vinyl guaiacol and gamma terpinene the majority ones. The AIT compared to the IPDT was more efficient in inhibiting oviposition of tick; however, the eggs laid by the females submitted to saturated atmosphere with essential oil, from IPDT, not hatched, interrupted their development cycle. Besides being a pioneer work, the results presented here contributes to new researches, aiming the incorporation of essential oil in an acaricide for use in the environment. © 2013 Springer-Verlag Berlin Heidelberg.

Estimativa da febre maculosa em cães para a vigilância e motitoramento da antropozoonose no municipio de Botucatu, no Estado de São Paulo

Pós-graduação em Medicina Veterinária - FMVZ

Diagnóstico de hemoparasitas em felídeos neotropicais provenientes de vida livre no Brasil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Flutuação populacional e distribuição espacial de Diaphorina citri Kuwayama (Hemiptera: Liviidae) em propriedades citrícolas com manejo intensivo do Huanglongbing

Pós-graduação em Agronomia (Entomologia Agrícola) - FCAV

Isolamento e identificação de bactérias solubilizadoras de fósforo e produtoras de auxinas em solo com cana-de-açúcar

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Frequency of antibodies to Babesia bigemina, B. bovis, Anaplasma marginale, Trypanosoma vivax and Borrelia burdgorferi in cattle from the northeastern region of the state of Pará, Brazil

A babesiose, a anaplasmose e a tripanossomose são enfermidades relevantes, potencialmente causadoras de morbidade em bovinos, levando a perdas econômicas. A borreliose assume importância como zoonose potencial. O objetivo desse estudo foi determinar, por meio do ensaio de imunoadsorção enzimática (ELISA), a freqüência de anticorpos para Babesia bigemina, B. bovis, Anaplasma marginale, Trypanosoma vivax e Borrelia burgdorferi em bovinos da região nordeste do Estado do Pará, Brasil. Amostras de soro de 246 vacas dos municípios de Castanhal e São Miguel do Guamá foram usadas. ELISAs com antígeno bruto foram utilizados para detector anticorpos contra todos os agentes, exceto para A. marginale, para o qual um ELISA indireto com proteína principal de superfície 1a (MSP1a) foi usado. As freqüências de bovinos soropositivos foram: B. bigemina - 99,2%; B. bovis - 98,8%; A. marginale - 68,3%; T. vivax - 93,1% and B. burgdorferi -54,9% As freqüências de bovinos soropositivos para B. bovis e B. bigemina sugerem uma alta taxa de transmissão desses organismos por carrapatos, na região estudada, a qual pode ser classificada com sendo de estabilidade enzoótica para os hemoparasitos. A baixa freqüência de bovinos soropositivos para A. marginale pode ser atribuída a uma menor sensibilidade do ELISA com antígeno recombinante, ou uma menor taxa de inoculação da riquétsia pelos carrapatos, quando comparada àquelas observadas para Babesia sp. A alta freqüência de bovinos soropositivos para T. vivax indica que esse hemoprotozoário é prevalente em rebanhos do nordeste do Estado do Pará. O percentual de animais com anticorpos homólogos para B. burgdorferi indica a presenças deste espiroquetídeo transmitido por carrapatos na população de bovinos da região estudada.

Carrapatos (Acari: Ixodidae) presentes em várias fitofisionomias de uma reserva no cerrado em Uberlândia, Minas Gerais, Brasil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Diagnóstico molecular de hemoparasitas e frequência de anticorpos anti-Toxoplasma gondii e anti-Neospora caninum, em gatos peridomiciliados na cidade de São Luís, Maranhão

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estatística espacial e redes neurais aplicadas no estudo de epidemias de huanglongbing e mancha preta na cultura dos citros

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)