Canine Monocytic Ehrlichiosis (CME) is an infectious disease caused by the rickettsia organism Ehrlichia canis which is transmitted mainly the ixodid brown dog tick Rhipicephalus sanguineus . The prevalence of E. canis infection has been increasing in recent years. The World Health Organization has been warned about antibiotics resistance and one of the way to prevent this situation is found new compound with this property. Doxycycline is the treatment of choice for this tick-borne disease. Adverse effects are noted in dogs that are sensitive to this drug. Antibiotic resistance may also occur. The present study aimed to evaluate the anti- Ehrlichia properties of the essential oil of the aerial parts of Ageratum conyzoides L. in infected DH82 cells, as well as its anti- Ehrlichia activity associated with doxycycline using the checkerboard assay. A. conyzoides is a native plant from northeast Brazil with many reports of ethnopharmacological applications. The essential oil of A. conyzoides was extracted from the aerial parts of the plant using the hydrodistillation method. E. canis -infected DH82 cells were cultured in DMEM (Dulbecco’s Modified Eagle Medium), maintained at 37 °C and 5% CO 2 , and standardized at a 70% infection rate for the initiation of treatment protocols. The tests were first carried out with the aim of defining the IC 50 . The combined effect of doxycycline and A. conyzoides essential oil was then determined using the checkerboard dilution technique (checkerboard method) in which the IC 50 was 200 µg/mL. The doxycycline reduction index from the combined effect was 4.90 times resulting in a synergistic effect. To the authors’ knowledge, this is the first alternative treatment (alternative therapy) based on bioactive molecules that have antibacterial activity against E. canis .

Ehrlichia canis is an intracellular bacterium that infects hematopoietic cells. It is the causative agent of canine monocytic ehrlichiosis (CME). The disease may be acute, subclinical, or chronic, and is treated with tetracyclines including doxycycline. However, this class of tetracyclines may cause several side effects due to prolonged treatment. Bacterial resistance to antimicrobials has been extensively reported. The present study aimed to assess the anti- Ehrlichia activity of the dichloromethane extract (DCM) of Ageratum conyzoides L. on Ehrlichia- infected DH82 cells. For this purpose, the DCM extract of A. conyzoides collected in the municipality of São Luís, State of Maranhão (MA), northeast Brazil, was obtained from the aerial parts of the plant by exhaustive percolation in H 2 O- CH 2 Cl 2 (2:8) and subsequent extraction of the chemical compound. The chemical composition of these samples was investigated. The anti- Ehrlichia properties of A. conyzoides were confirmed in Ehrlichia- infected DH82 cells at a concentration of 200 μg.mL -1 of its DCM extract. The results of the treatments were evaluated at 18h and 36h after the insertion of the treatments evaluated with A. conyzoides.Based on the results of the chemical analysis of the samples, we may attribute these antirickettsial properties to the compounds from the lignan family that are found in this medicinal plant .

Mycoplasma suis is a bacterium that causes hemoplasmosis in pigs. This agent is capable of adhering to the surface of porcine erythrocytes, inducing structural changes on these cells. In Brazil, there are few reports about the disease, its causal agent, and the economic impact of this pathogen on pig production systems and farm sanitation. The present study aimed to investigate the occurrence of M. suis in extensive swine farms located in the counties of Itapecuru Mirim, Santa Rita and Rosario, State of Maranhão, northeast Brazil. For such purpose, 64 blood samples of pigs from these facilities were tested for M. suis using a 16S rRNA gene-based quantitative real-time PCR (qPCR); 82.3%, 65.2% and 25% of blood samples of swine from farms in the cities of Itapecuru Mirim, Santa Rita and Rosario were positive for M. suis by qPCR, respectively. This study shows, for the first time, that M. suis circulates in pig populations from the state of Maranhão, Northeast Brazil.

Anaplasma marginale is an obligate intracellular Gram-negative bacterium found in ruminants’ erythrocytes and is the etiological agent of bovine anaplasmosis. The bacterium’s genetic diversity has been characterized based on sequences of major surface proteins (MSPs), such as MSP1α. The aim of the present study was to investigate the genetic diversity of A. marginale in cattle in the state of Maranhão, northeastern Brazil. To this end, 343 blood samples were harvested and subjected to iELISA assays using the recombinant surface protein MSP5. Out of 343 blood samples, 235 (68.5%) were randomly chosen and submitted to DNA extraction, qPCR and conventional PCR targeting the msp1α gene to determine amino acid sequences and classify the genotypes. The iELISA results showed 81.34% seropositivity (279/343), whereas qPCR revealed 224 positive samples (95.32%). Among these qPCR-positive samples, 67.4% (151/224) were also positive in the cPCR. Among the 50 obtained sequences, 21 strains had not been previously reported. Regarding the genotypes, H (26/50) and E (18/50) were identified most often, while genotypes F and C were only identified twice each and B and G once each. In conclusion, high prevalence and genetic diversity for A. marginale were observed in dairy cattle herds in the state of Maranhão.

RESUMO: As leishmanioses têm como agentes etiológicos parasitas intracelulares obrigatórios pertencentes ao gênero Leishmania capazes de infectar diferentes espécies de mamíferos e nestes se reproduzirem dentro do sistema fagocítico mononuclear. Os cães domésticos são os principais responsáveis pela manutenção da cadeia epidemiológica da doença, podendo apresentar uma grande variedade de perfis clínicos, desde aparentemente sadios a severamente acometidos. Avaliou-se a expressão das citocinas de cães naturalmente infectados com Leishmania (Leishmania) chagasi. Foram coletadas 50 amostras, sendo 20 de animais positivos e sintomáticos para Leishmaniose Visceral Canina (LVC), 20 de animais positivos e assintomáticos e 10 de animais sabidamente negativos para a LVC. As amostras foram analisadas pelo teste imunocromatográfico rápido Dual Path Platform (DPP/Biomanguinhos®) e pelo ELISA (EIE/Biomanguinhos®) indireto para detecção de anticorpos anti-Leishmania. Após as confirmações dos testes, foi realizado o ELISA de captura (R & D Systems) para quantificação das citocinas IL-10 e IFN-γ. Houve diferença estatística entre os grupos observando um aumento nos níveis de IFN-γ nos animais assintomáticos e um aumento de IL-10 nos sintomáticos.

RESUMO: As leishmanioses compreendem um complexo de doenças causadas por parasitos intracelulares obrigatórios pertencentes ao gênero Leishmania. Consideradas como importante problema de saúde pública, sendo os cães domésticos os principais responsáveis pela manutenção da cadeia epidemiológica da doença, estima-se que mais da metade dos cães infectados não manifestam sinais clínicos da enfermidade. Avaliou-se o perfil de IL-10 e INF- γ de cães naturalmente infectados com Leishmania (Leishmania) chagasi no município de São Luís-MA. Foram coletadas 50 amostras, sendo 20 de animais positivos e sintomáticos para Leishmaniose Visceral Canina (LVC), 20 de animais positivos e assintomáticos e 10 de animais sabidamente negativos para a LVC. As amostras foram analisadas pelo teste imunocromatográfico rápido Dual Path Platform (DPP/Biomanguinhos®) e pelo ELISA (EIE/Biomanguinhos®) indireto para detecção de anticorpos anti-Leishmania. Após as confirmações dos testes, foi realizado o ELISA de captura para quantificação das citocinas IL-10 e INF-γ através do kit Milliplex MAP. Houve diferença estatística entre os grupos, observando um aumento de IL-10 em soros de cães sintomáticos para LVC, comparado com o grupo de animais assintomáticos, sugerindo que animais com essa expressão de IL-10 podem estar associados à susceptibilidade a doença. Assim como o aumento dos níveis de INF-γ observados em cães assintomáticos, comparado com o grupo de cães sintomáticos, poderiam estar relacionados à cronicidade da doença.

Direitos para esta edição cedidos à Atena Editora pelos autores. Open access publication by Atena Editora Todo o conteúdo deste livro está licenciado sob uma Licença de Atribuição Creative Commons. Atribuição-Não-Comercial-NãoDerivativos 4.0 Internacional (CC BY-NC-ND 4.0). O conteúdo dos artigos e seus dados em sua forma, correção e confiabilidade são de responsabilidade exclusiva dos autores, inclusive não representam necessariamente a posição oficial da Atena Editora. Permitido o download da obra e o compartilhamento desde que sejam atribuídos créditos aos autores, mas sem a possibilidade de alterá-la de nenhuma forma ou utilizá-la para fins comerciais.Todos os manuscritos foram previamente submetidos à avaliação cega pelos pares, membros do Conselho Editorial desta Editora, tendo sido aprovados para a publicação com base em critérios de neutralidade e imparcialidade acadêmica.A Atena Editora é comprometida em garantir a integridade editorial em todas as etapas do processo de publicação, evitando plágio, dados ou resultados fraudulentos e impedindo que interesses financeiros comprometam os padrões éticos da publicação. Situações suspeitas de má conduta científica serão investigadas sob o mais alto padrão de rigor acadêmico e ético.

Enzootic bovine leukosis (EBL) is a chronic viral disease of wide distribution in cattle herds and may take several years for the first manifestation of clinical signs. Most animals do not present clinical signs. However, the economic losses are underestimated due to this disease. Thus, this work aimed to detect and characterize BLV in dairy cattle in the Maranhão state, northeastern Brazil. Blood samples were collected from 176 animals from 8 municipalities in the southeastern state of Maranhão. Bovine blood samples were subjected to DNA extraction and molecular diagnosis using nested PCR assays for BLV, targeting gp51 gene. Positive samples were then sequenced and then subjected to phylogenetic inferences. BLV DNA was detected in 16 cattle (16/176, 9.09%) in 4 municipalities. Phylogenetic analyzes showed that the sequence obtained clustered in a clade containing BLV sequences classified as genotype 6, with a high degree of support. Our data shows BLV occurrence in the Northeast of Brazil and the identification of genotype 6 in this region. These findings contribute to the molecular epidemiology of this agent in Brazil.