RESUMO
Zika virus (ZIKV) infection in utero might lead to microcephaly and other congenital defects. Since no specific therapy is available thus far, there is an urgent need for the discovery of agents capable of inhibiting its viral replication and deleterious effects. Chloroquine is widely used as an antimalarial drug, anti-inflammatory agent, and it also shows antiviral activity against several viruses. Here we show that chloroquine exhibits antiviral activity against ZIKV in Vero cells, human brain microvascular endothelial cells, human neural stem cells, and mouse neurospheres. We demonstrate that chloroquine reduces the number of ZIKV-infected cells in vitro, and inhibits virus production and cell death promoted by ZIKV infection without cytotoxic effects. In addition, chloroquine treatment partially reveres morphological changes induced by ZIKV infection in mouse neurospheres.
Assuntos
Antivirais/farmacologia , Cloroquina/farmacologia , Endocitose/efeitos dos fármacos , Infecção por Zika virus/virologia , Zika virus/efeitos dos fármacos , Zika virus/fisiologia , Animais , Linhagem Celular , Chlorocebus aethiops , Humanos , CamundongosRESUMO
Babesiosis, anaplasmosis, and trypanosomosis are relevant diseases, potentially causing morbidity in cattle, leading to economic losses. Borreliosis is import as a potential zoonosis. The objective of this study was to determine, by indirect enzyme-linked immunosorbent assay (ELISA), the frequency of seropositive cattle to Babesia bigemina, B. bovis, Anaplasma marginale, Trypanosoma vivax and Borrelia burgdorferi in cattle from the Northeastern region of Pará, Brazil. Sera samples from 246 female adult cattle from municipalities of Castanhal and São Miguel do Guamá were used. Crude antigens ELISAs were used to detect antibodies to all agents, except to A. marginale, to which an indirect ELISA with recombinant major surface 1a protein (MSP1a) antigen was used. Overall frequencies of seropositive animals were: B. bigemina--99.2%; B. bovis--98.8%; A. marginale--68.3%; T. vivax--93.1% and B. burgdorferi--54.9%. The frequencies of seropositive cattle to B. bovis and B. bigemina suggest a high rate of transmission of these organisms by tick in the studied region, which can be classified as enzootically stable to these hemoprotozoans. The low frequency of seropositive cattle to A. marginale may be attributed to a lower sensitivity of the recombinant antigen ELISA utilized or a distinct rate of inoculation of this rickettsia by ticks, as compared with Babesia sp. transmission. The high frequency of seropositive cattle to T. vivax indicates that this hemoprotozoan is prevalent in herds from the Northeastern region of Pará. The rate of animal that showed homologues antibodies to B. burgdorferi indicates the presence of the tickborne spirochaetal agent in the cattle population in the studied region.
Assuntos
Anaplasma marginale/imunologia , Antígenos de Bactérias/sangue , Antígenos de Protozoários/sangue , Babesia/imunologia , Borrelia burgdorferi/imunologia , Bovinos/sangue , Trypanosoma vivax/imunologia , Animais , Brasil , FemininoRESUMO
Artificial feeding is an important toll for studying ticks feeding mechanism and transmission of pathogenic agents in the absence of vertebrate host. The objective was to feed artificially of engorged partially females of Dermacentor (Anocentor) nitens, proceeding of infested naturally equines and evaluate the influence of this technique on biological parameters of species. Engorged partially females were collected, weighted and separate by weight in two range of 40 to 60 milligrams and 61 to 100 milligrams. Each range was further sorted in four groups with homogeneous weight which were fed for 6, 12, 24 and 36 hours through capillaries tubes containing citrated bovine blood. It was observed that artificial feeding promoted increase weight of females in both range and definitive times. The Ticks fed artificially for periods more drawn out, had presented parameters of the non-parasitic phase next to the observed ones in conditions to laboratory for this species. Females of D. (A.) nitens partially engorged ingested great volume of blood when submitted to artificial feeding through capillaries tubes, without any effect in their biological parameters.
Assuntos
Dermacentor/fisiologia , Animais , Dermacentor/crescimento & desenvolvimento , Métodos de Alimentação , FemininoRESUMO
The study aimed to evaluate the risk factors associated with the frequency of IgG antibodies against Babesia bovis and B. bigemina in cattle in southern Mozambique. Eight hundred and nine serum samples were collected from cattle in three provinces namely Maputo, Gaza and Inhambane, and tested by indirect enzyme-linked immunosorbent assay (i-ELISA) to assess the humoral immune response towards B. bovis and B. bigemina. The chi-square test at 5 percent significance was used to determine whether there was an association between gender, age and geographic origin of seropositive animals. The overall prevalence was 78.8 percent (548/695) for B. bovis and 76.0 percent (528/695) for B. bigemina. The origin of the animals showed a significant association (p<0.05) with seropositivity to both agents, while gender and age was not associated (p>0.05). Maputo province had the highest rate of positive animals, with 93.7 percent (118/126) for B. bovis and 97.6 percent (123/126) for B. bigemina. In Gaza province 77.3 percent (321/415) of the animals were positive for B. bovis and 67.5 percent (280/415) for B. bigemina, while in the province of Inhambane the levels of seropositivity were 70.8 percent (109/154) and 81.2 percent (125/154) for B. bovis and B. bigemina respectively. In the present study, the frequency of cattle positive for B. bovis and B. bigemina was shown to increase among older age groups, suggesting that infection and re-infection persisted even after the primary infection. Thus, this region is considered to be in a state of enzootic stability with regards to B. bovis and B. bigemina.
Foram avaliados os fatores de risco associados a frequência de anticorpos da classe IgG contra Babesia bovis e B. bigemina em bovinos da região sul de Moçambique. Oitocentos e nove amostras de soros foram coletadas de bovinos em três províncias nomeadamente Maputo, Gaza e Inhambane e testados por ensaio de imunoadsorção enzimático indireto (i-ELISA) para avaliar a resposta imune humoral contra B. bovis e B. bigemina. O teste de Qui-quadrado a 5 por cento de significância foi utilizado para verificar a associação entre as variáveis sexo, faixa etária e origem geográfica com a soropositividade dos animais. A prevalência geral foi de 78,8 por cento (548/695) para B. bovis e 76,0 por cento (528/695) para B. bigemina. A origem dos animais apresentou associação (p<0,05) com a soropositividade a ambos os agentes, enquanto variável sexo não apresentou associação (p>0,05). A província de Maputo apresentou a maior taxa de animais positivos, com 93,7 por cento (118/126) para B. bovis e 97,6 por cento (123/126) para B. bigemina. Na província de Gaza a soropositividade foi de 67,5 por cento (280/415) para B. bigemina e 77,3 por cento (321/415) para B. bovis enquanto que na província de Inhambane a positividade foi de 81,2 por cento (125/257) e 70,8 por cento (109/257) para B. bigemina e B. bovis, respectivamente. Na presente pesquisa, a freqüência de bovinos positivos para B. bovis e B. bigemina aumentou nas faixas etárias superiores, sugerindo que as infecções e as re-infecções persistem mesmo após primo-infecção. A região estudada apresenta-se na condição de estabilidade enzoótica para os agentes estudados.
RESUMO
Borreliose aviária é uma doença septicêmica aguda, cosmopolita, que acomete diferentes espécies aviárias, sendo causada por Borrelia anserina Sakharoff, 1891. O objetivo do presente trabalho foi avaliar as alterações hematológicas em Gallus gallus domesticus experimentalmente infectados por B. anserina via vetor Argas (Persicargas) miniatus. Um total de 27 aves da espécie G. g. domesticus com 67 dias de vida, foram divididas em três grupos inteiramente casualizados contendo nove animais cada. Um grupo foi exposto a carrapatos infectados por B. anserina (Grupo 1); outro a carrapatos livres deste agente (Grupo 2); além de um grupo não exposto aos carrapatos (Grupo 3). Realizaram-se esfregaços sangüíneos diariamente, a partir do primeiro dia de exposição ao vetor, até o 25º dia pós-exposição (DPE). Amostras de sangue foram coletadas 3 dias antes da exposição aos carrapatos, e 3, 8 e 18 dias pós-exposição (DPE), para a realização dos hemogramas. O exame dos esfregaços das aves do Grupo 1 revelou grande número de espiroquetas. Os esfregaços sangüíneos dos Grupos 2 e 3 mantiveram-se negativos durante todo o período experimental. De acordo com os resultados das avaliações hematológicas, as aves do Grupo 1 apresentaram um quadro de anemia normocítica normocrômica em oito DPE, além de leucocitose com heterofilia e monocitose que cursaram paralelamente ao período de espiroquetemia. Concluiu-se que a infecção por B. anserina determinou nas aves do Grupo 1 alterações hematológicas compatíveis com uma infecção bacteriana de moderada gravidade, evoluindo para auto-cura, nas condições experimentais estabelecidas neste trabalho.(AU)
Avian spirochaetosis is a cosmopolite acute septicemic disease of many avian species, caused by Borrelia anserina Sakharoff, 1891. The present study assesses the estimate of the hematological alterations of Gallus gallus domesticus experimentally infected with B. anserina by vector Argas (Persicargas) miniatus. Twenty-seven fowls of the species G. g. domesticus, 67 days old, were randomly allocated into three groups composed by nine animals each. One group was exposed to B. anserina infected ticks (Group 1), other one to ticks free of this agent (Group 2), and another group not exposed to ticks (Group 3). Blood smears of the fowls were taken daily, since the first day the fowls were exposed to the ticks, up to the 25th day after exposure (DAE). Blood samples were collected three days before exposure, and three, eight and 18 DAE, for hematologic tests. The examination of Group 1 smears revealed large number of spirochaetes. Group 2 and 3 blood smears were negative during the whole period under exam. In agreement with the hematological evaluation results, the fowls exposed to infected ticks showed a normocytic normochromic anemia in eight DAE, leucocytosis with heterophilia and monocytosis concomitant with the spirochaetemia. We concluded that B. anserina infection determined on fowls of Group 1 hematological alterations compatible with bacterial infection of moderate gravity, developing to self-cure, in the experimental conditions established in this study.(AU)
Assuntos
Animais , Borrelia , Galinhas/sangue , Testes Hematológicos , Infecções por Spirochaetales , Infecções BacterianasRESUMO
Babesiosis, anaplasmosis, and trypanosomosis are relevant diseases, potentially causing morbidity in cattle, leading to economic losses. Borreliosis is import as a potential zoonosis. The objective of this study was to determine, by indirect enzyme-linked immunosorbent assay (ELISA), the frequency of seropositive cattle to Babesia bigemina, B. bovis, Anaplasma marginale, Trypanosoma vivax and Borrelia burgdorferi in cattle from the Northeastern region of Pará, Brazil. Sera samples from 246 female adult cattle from municipalities of Castanhal and São Miguel do Guamá were used. Crude antigens ELISAs were used to detect antibodies to all agents, except to A. marginale, to which an indirect ELISA with recombinant major surface 1a protein (MSP1a) antigen was used. Overall frequencies of seropositive animals were: B. bigemina - 99.2 percent; B. bovis - 98.8 percent; A. marginale - 68.3 percent; T. vivax - 93.1 percent and B. burgdorferi - 54.9 percent. The frequencies of seropositive cattle to B. bovis and B. bigemina suggest a high rate of transmission of these organisms by tick in the studied region, which can be classified as enzootically stable to these hemoprotozoans. The low frequency of seropositive cattle to A. marginale may be attributed to a lower sensitivity of the recombinant antigen ELISA utilized or a distinct rate of inoculation of this rickettsia by ticks, as compared with Babesia sp. transmission. The high frequency of seropositive cattle to T. vivax indicates that this hemoprotozoan is prevalent in herds from the Northeastern region of Pará. The rate of animal that showed homologues antibodies to B. burgdorferi indicates the presence of the tickborne spirochaetal agent in the cattle population in the studied region.
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 por cento; B. bovis - 98,8 por cento; A. marginale - 68,3 por cento; T. vivax - 93,1 por cento and B. burgdorferi -54,9 por cento 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.