Serologic evidence of equine granulocytic anaplasmosis in horses from central West Brazil

A Erliquiose é uma doença zoonótica causada por bactérias gram-negativas e intracelulares obrigatórias. A Anaplasmose Granulocítica Equina - AGE (anteriormente denominada Erliquiose Granulocítica Equina, EGE) é uma enfermidade sazonal, normalmente auto-limitante em equinos. No Brasil, existem poucos relatos deste agente erliquial, bem como de seus vetores naturais. Atualmente, veterinários têm levantado a suspeita de casos de AGE em equinos com sinais clínicos sugestivos de erliquiose e não responsivos ao tratamento para a piroplasmose equina. O objetivo do presente estudo foi identificar equinos expostos a A. phagocytophilum por meio de técnicas sorológicas e moleculares. Vinte amostras de sangue e soro de equinos da região Centro-oeste do Brasil foram avaliados por meio do exame microscópico de capa leucocitária, ensaio imunoenzimático indireto (ELISA), reação de imunofluorescência indireta (RIFI) e reação em cadeia da polimerase (nested PCR). Adicionalmente, o diagnóstico sorológico de Theileria equi pela RIFI e ELISA foram realizados, assim como o diagnóstico molecular pelo nPCR. Treze (65%) amostras de soro foram positivas para A. phagocytophilum pelo teste de ELISA, entretanto nenhum equino foi positivo pelo exame microscópico da capa leucocitária ou nPCR. Anticorpos IgG anti-T. equi foram detectados em 18 (90%) e 17 (85%) equinos pela RIFI e ELISA, respectivamente e o agente foi detectado em 9 (45%) animais pelo nPCR. Estes dados sugerem importante informação para o entendimento da ocorrência da AGE e piroplasmose equina no Centro-oeste do Brasil.

Uveitis due to anaplasmosis in a newborn Holstein calf

Relata-se o caso de um bovino com, aproximadamente, seis horas de vida, apresentando histórico de febre, apatia, inapetência e desconforto ocular. No exame oftálmico rotineiro, encontraram-se valores do teste da lágrima de Schirmer aumentados, diminuição da pressão intra-ocular, hemorragia conjuntival, uveíte anterior, edema corneal e injeção ciliar em ambos os olhos. Coletou-se amostra de sangue para realização de esfregaço sangüíneo, hemograma e bioquímica sérica. No esfregaço visibilizaram-se corpúsculos de Anaplasma marginale em hemácias parasitadas. Quanto à bioquímica sérica, não foram observadas alterações. Os mesmos exames foram realizados na mãe do animal tendo como resultado a positividade para A. marginale. Para o controle da uveíte foi utilizada uma única aplicação de 0,5ml de betametasona a 5%, por via subconjuntival, em cada um dos olhos. Para o tratamento da anaplasmose, seguiu-se o protocolo a base de 10mg/kg de oxitetraciclina, por via intramuscular profunda, a cada 12 horas. Diante os achados oftálmicos e a presença de corpúsculos de A. marginale em hemácias parasitadas, contatou-se, ser um caso de uveíte crônica secundaria a doença sistêmica, factível com Anaplasmose.

Risk factors for anaplasmosis in dairy cows during the peripartum

Anaplasma marginale is endemic in tropical and subtropical areas around the world. Some studies have suggested that cows during peripartum may present a transient immunosuppression state and development of clinical signs of anaplasmosis. The aim of this study was to investigate the relationship between some risk factors and the seroprevalence of A. marginale in dairy cows during peripartum in Rio de Janeiro, Brazil. The risk factors analyzed in association with the prevalence of antibodies against A. marginale in dairy cows were calving season, reproductive experience, breed standard, tick infestations, stocking density, and milk yield. The antibodies against A. marginale were tested in indirect enzyme-linked immunosorbent assays. A primary screening using a 2 x k contingency table of the exposed variables with the outcomes was performed. All variables for which p < 0.20 were included in a fixed effects log regression. The risk factors investigated to anaplasmosis were calving (OR 2.61, IC 1.08-7.63), breed standard (OR 3.83, IC 0.08-0.28), reproductive experience (OR 33.7, IC 2.14-5.16), milk yield (OR 3.9, IC 2.24-7.03), Rhipicephalus microplus infestations (OR 10.3, IC 0.05-0.17), and stocking density (OR 22.3, IC 0.05-0.17). Low titers of antibodies against A. marginale during peripartum had been characterized as a period previous to development of clinical anaplasmosis. Thus, studies on anaplasmosis should consider each farm as an epidemiological unit, where environmental and immunological factors may influence the endemic status of the pathogen.

Low genetic diversity of Anaplasma marginale in calves in an endemic area for bovine anaplasmosis in the state of São Paulo, Brazil

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

Detection of Ehrlichia chaffeensis in Brazilian marsh deer (Blastocerus dichotomus)

Ehrlichia chaffeensis was detected for the first time in blood samples from Brazilian marsh deers (Blastocerus dichotomus) captured in the marshes of Parana River in Southeast Brazil in 1998. Seven EDTA-blood samples from deers were analyzed by PCR and nested PCR for presence of Ehrlichia chaffeensis, Ehrlichia ewingii, Ehrlichia canis, Neoriickettsia risticii, Anaplasma phagocytophilum and Anaplasma marginale. Three samples showed positive reactions for E. chaffeensis and Anaplasma marginale. None contained detectable A. phagocytophilum, E. ewingii, E. canis or Neorickettsia risticii DNA. In Brazil, the wild marsh deer may be a natural reservoir of the agents that cause human monocytotropic ehrlichiosis and ruminant erythrocytic anaplasmosis. (c) 2006 Elsevier B.V. All rights reserved.

Survey for Tick-Borne Zoonoses in the State of Espirito Santo, Southeastern Brazil

Blood samples collected from 201 humans, 92 dogs, and 27 horses in the state of Espirito Santo, Brazil, were tested by polymerase chain reaction, indirect immunofluorescence assays, and indirect enzyme-linked immunosorbent assay for tick-borne diseases (rickettsiosis, ehrlichiosis, anaplasmosis, borreliosis, babesiosis). Our results indicated that the surveyed counties are endemic for spotted fever group rickettsiosis because sera from 70 (34.8%) humans, 7 (7.6%) dogs, and 7 (25.9%) horses were reactive to at least one of the six Rickettsia species tested. Although there was evidence of ehrlichiosis (Ehrlichia canis) and babesiosis (Babesia cams vogeli, Theileria equi) in domestic animals, no human was positive for babesiosis and only four individuals were serologically positive for E. canis. Borrelia burgdorferi-serologic reactive sera were rare among humans and horses, but encompassed 51% of the canine samples, suggesting that dogs and their ticks can be part of the epidemiological cycle of the causative agent of the Brazilian zoonosis, named Baggio-Yoshinari Syndrome.

Immunization of bovines using a DNA vaccine (pcDNA3.1/MSP1b) prepared from the jaboticabal strain of Anaplasma marginale

Anaplasma is a tick-borne ehrlichial pathogen of cattle that causes the disease, anaplasmosis. In the present study, a total of 11 Anaplasma marginale seronegative calves were assigned into two groups: one immunized (G1, n = 6) and one nonimmunized-control (G2, n = 5). Six calves were immunized by using a DNA vaccine containing the gene of a major surface protein, MSP1b, encoded by the plasmid identified as pcDNA3.1/MSPIb. Calves received three intramuscular inoculations of 100 mug of pcDNA3.1/MSP1b at a 20-day interval. The control group received buffer phosphate at the same schedule as the experimental group. The immune response elicited by immunization with pcDNA3.1/MSP1b was evaluated in mice and calves. Twenty days following initial immunization, specific serum antibody from four BALB/c mice bound MSP1b in inummoblots. Sixty days after the last immunization, all calves were challenged with cryopreserved A. marginale at a dose of 10(4) parasites/mL/animal by intravenous injection. Results of packed cell volume (PCV) and detection of infected erythrocytes in all experimental groups revealed that the decrease of PCV and detection of infected erythrocytes occurred at 28 to 42 days after challenge. Mean temperature values did not increase over 39.85degreesC. Antibodies developed by immunized bovines from G2 were detected 14 days after challenge. MSP1b was characterized during the immunization period and MSP2 was the most predominant polypeptide at the challenge period. DNA of A. marginale was detected in all groups just after challenge by nested PCR assay. It can be concluded that all immunized bovines were partially protected against homologous challenge.

Analysis of the risk factors related to the immune humoral anti-Anaplasma marginale in dairy cattle

Anaplasma marginale is the most prevalent pathogen of cattle transmitted by ticks in the world. This study aimed to evaluate the risk factors for anaplasmosis in dairy cattle. Fifty dairy cattle from the herd of Empresa de Pesquisa Agropecuaria do Estado do Rio de Janeiro were selected by proportional stratified sampling. The risk factors evaluated were: physiological state, race pattern, number of lactations, milk production, infestation by Rhipicephalus microplus and animal density. Antibody activity against A. marginale was determined using the indirect enzyme-linked immunosorbent assay. The percentual values of seroprevalence for A. marginale were submitted to X2 test, and the level of minimum significance, to keep a factor in the model of logistic regression, was fixated in 5%. It was observed that pregnancy and lactation influenced significantly (p<0.05) in the seropositivity of the animals. Bos indicus animals had 5.21 times more chances of being seropositive than B. taurus animals. Primiparous female had 88% more chances of being seropositive than pluriparous female. Animals with high milk production were 63% more positive than low production animals. When infested by ticks the animals had 39% more chance of being seropositive to A. marginale. Bos indicus animals presented 5.21 times more chance of being seropositive than B. taurus animals. Primiparous females presented 88% more chance of being seropositive than the pluriparous ones. High milk production animals were 63% more positive than the low production ones. When infested by ticks the animals had 39% more chance of being seropositive to A. marginale. High density grazing provided for the animals 3.2 times more chances of being seropositive than low density ones. The herd was classified as erratic to A. marginale, even being placed in a steady enzootic area.

Detecção sorológica e molecular de Anaplasma marginale em búfalos na Ilha de Marajó, Pará

The aim of the study was to test the molecular and serological prevalence of Anaplasma marginale in water buffaloes of the Marajó Island, State of Pará, Brazil. For serologic research were randomly selected 800 buffaloes and for molecular research 50 of these animals were randomly chosen. To quantify the serological prevalence we used the indirect enzyme linked immunosorbent assay (iELISA) with total antigen containing proteins outer surface. To quantify the prevalence molecular was used the polymerase chain reaction (PCR) involving gene amplification fragment larger surface protein 5 (MSP5). The prevalence of positive animals in iELISA was 25% (200/800). In the PCR we detected the presence of A. marginale in 2% (1/50) of animals. Although only one animal was positive in PCR, we found that it was negative in ELISA. The presence of the agent, even in low prevalence, shows that buffaloes can act as an important reservoir for transmission of the pathogen to cattle in northern Brazil.

Molecular and serological prevalence of Anaplasma marginale in water buffaloes in northern Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Low genetic diversity associated with low prevalence of Anaplasma marginale in water buffaloes in Marajo Island, Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Infection of water buffalo in Rio de Janeiro Brazil with Anaplasma marginale strains also reported in cattle

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ocorrência sorológica de Babesia bovis, Babesia bigemina e Anaplasma marginale em bovinos e bubalinos no estado do Pará, Brasil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)