Comparative evaluation of several methods for Canine Visceral Leishmaniasis diagnosis

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

Morphological changes in the bone marrow of the dogs with visceral leishmaniasis

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

Biological characterization of the Amazon coral Micrurus spixii snake venom: isolation of a new neurotoxic phospholipase A2

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Genome-wide scan for visceral leishmaniasis in mixed-breed dogs identifies candidate genes involved in T helper cells and macrophage signaling

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

Evaluating the microbicidal, antiparasitic and antitumor effects of CR-LAAO from Calloselasma rhodostoma venom

CR-LAAO is an l-amino acid oxidase from Calloselasma rhodostoma snake venom that has been broadly studied regarding its structural and biochemical characteristics, however, few studies have investigated its pharmacological effects. The present study aimed at the evaluation of the biotechnological potential of CR-LAAO by determining its bactericidal, antifungal, leishmanicidal and trypanocidal activity, as well as its cytotoxicity on human tumor and non-tumor cell lines. After 24h of preincubation, CR-LAAO showed bactericidal effects against both Staphylococcus aureus (MIC 0.78μg/mL) and Escherichia coli (MIC 31.25μg/mL) strains, inducing dismantle of bacterial cell walls. After 6h of preincubation with Candida albicans, CR-LAAO was able to inhibit 80% of the yeast growth, and it also showed cytotoxic activity on Leishmania species and Trypanosoma cruzi. Additionally, CR-LAAO showed high cytotoxicity on HepG2 and HL-60 tumor cells (IC50 10.78 and 1.7μg/mL), with lower effects on human mononuclear cells (PBMC). The cytotoxic effects of CR-LAAO were significantly inhibited in the presence of catalase, which suggests the involvement of hydrogen peroxide in its mechanisms of toxicity. Therefore, CR-LAAO showed promising pharmacological effects, and these results provide important information for the development of therapeutic strategies with directed action, such as more effective antimicrobial agents.

Synthesis and evaluation of novel prenylated chalcone derivatives as anti-leishmanial and anti-trypanosomal compounds

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

Antimicrobial and antileishmanial activities of diterpenoids isolated from the roots of salvia deserta

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Novel markers of inflammatory response and hepatic dysfunction in canine leishmaniasis

Dogs are the main host of Leishmania infantum, and the clinical presentation may range from asymptomatic to systemic manifestations. The immune mechanisms in infected, but clinically healthy dogs, prevails Th1 response mediated by cytokines. In this sense, adenosine deaminase (ADA) and butyrylcholinesterase (BChE) are considered as key enzymes in several physiological processes, including the modulation of inflammatory process. Considering the variable immune response against Leishmania and the known participation of ADA and BChE, the aim of this study was to assess the relation between these two enzymes with the inflammatory response as well as hepatic function in dogs naturally infected with L. infantum. For this purpose, the activity of ADA and BChE was assessed in sera of 24 dogs naturally infected with L. infantum, plus 17 healthy dogs. The naturally infected dogs had clinical signs compatible with leishmaniasis and sera activities of ADA (P<0.01) and BChE (P<0.05) decreased, when compared to the healthy group. The reduction of ADA activity probably represented an effect on inflammatory response, especially due to the decreased hydrolysis of extracellular adenosine, might in order to protect against tissue damage and, also, setting a down-regulation on pro-inflammatory cytokines. BChE enzyme had no effect on modulating the immune response in leishmaniasis, but it decreased, a fact may related to deficiency of synthesis in the liver. Therefore, ADA and BChE activities reduced probably in order to protect against extra tissue damage and due failure in synthesis, respectively.

The shadows of a ghost: a survey of canine leishmaniasis in Presidente Prudente and its spatial dispersion in the western region of São Paulo state, an emerging focus of visceral leishmaniasis in Brazil

Visceral leishmaniasis is an emerging zoonosis and its geographic distribution is restricted to tropical and temperate regions. Most of the individuals infected in Latin America are in Brazil. Despite the control measures that have been adopted, the disease is spreading throughout new regions of the country. Domestic dogs are involved in the transmission cycle and are considered to be the main epidemiologic reservoir of Leishmania infantum (syn. L. chagasi). Our aim was to determine the prevalence of canine leishmaniasis (CL) and Ehrlichiosis infection in Presidente Prudente as well as the spatial dispersion of the disease in the western region of São Paulo state. Dogs underwent clinical examination and symptoms related to CL were recorded. Anti- Leishmania antibodies were detected using ELISA, rK39-immunocromatographic tests (DPP), and an indirect fluorescent antibody test (IFAT). Anti-E. canis antibodies were detected by IFAT. A follow-up was conducted in dogs that were positive in the ELISA at the baseline study. Data on the spatial distribution of L. longipalpis and CL in São Paulo state were obtained from Brazilian public health agencies. Serum samples from 4547 dogs were analyzed. The seroprevalence of CL was 11.2 % by ELISA and 4.5 % by IFAT. In the follow-up, seroprevalence was 32.9 % by ELISA, 15.3 % by IFAT, 11.8 % by DPP test, and 66.5 % for E. canis. There was a significant positive association between Leishmania and E. canis infection (P < 0.0001). In the follow-up, clinical examinations revealed symptoms compatible with CL in 33.5 % of the dogs. L. longipalpis was found in 24 and CL in 15 counties of the Presidente Prudente mesoregion. The dispersion route followed the west frontier of São Paulo state toward Paraná state. Low CL and high ehrlichiosis prevalence rates were found in Presidente Prudente city. This emerging focus of CL is moving through the western region of São Paulo state toward the border of Paraná state. Integrated actions to fight the vector, parasites, infected dogs, and humans are needed to monitor the disease and implement strategies for epidemiologic control.

Avaliação hepática de cães naturalmente infectados por leishmaniose visceral canina: aspectos ultrassonográficos modo B e Doppler

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

Comparison of diferent diagnostic tests in dogs uninfected and naturally infected with visceral leishmaniasis

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

Orientação sobre posse responsável em uma área endêmica para leishmaniose visceral canina

The purpose of this work was to provide guidance to householders in the responsible care of their pets, in a region where canine visceral leishmaniasis is endemic. Questionnaires on responsible ownership and the control of this disease were completed by owners of dogs and cats in the city of Araçatuba, São Paulo State, Brazil, in order to evaluate their level of knowledge. Based on the identified deficiencies, the project team provided the owners of the pets with individual guidance at home, focusing on the most critical issues. Concerning nutrition, 70.45% (62/88) of owners provided pet food only, 27.28% (24/88) administered a mixed diet, and 2.27% (2/88) provided homemade food. Additionally, 78.41% (69/88) did not permit the consumption of raw meat, rare meat, or bones. 9.09% (8/88) of owners allowed their pets to wander the neighborhood alone. Among dogs, 14.77% (13/88) had never been clinically tested by a qualified professional, and 6.82% (6/88) and 15.91% (14/88) had never received any kind of vaccine or vermifuge, respectively. In relation to population control, only 20.45% (18/88) of the dogs had been sterilized. It was also observed that 25% (22/88) of owners had already had canine visceral leishmaniasis seropositive dogs in their homes. 54.55% (12/22) of these owners had referred their pets to veterinary clinics for euthanasia, 22.73% (5/22) had used the services of the city’s animal disease control center, and 18.18% (4/22) had paid for private treatment. Nevertheless, 35.23% (31/88) of the dogs had never been submitted to tests for infection diagnosis. From the results obtained, it could be inferred that the individuals who participated in this study were poorly informed concerning basic pet care, demonstrating a need to implement community awareness campaigns for the responsible ownership of pets.

Avaliação do grau de conhecimento sobre Leishmaniose e Toxoplasmose em moradores do município de Araçatuba, SP

Considering the importance of zoonotic infections by Leishmania spp. and Toxoplasma gondii in Araçatuba region, São Paulo, this study determined the degree of knowledge of residents of Araçatuba about these two diseases. Questionnaires about these diseases were applied to 123 people. Regarding schooling, all the respondents were literate, and 69.9% (86/123) did not attend higher education and 30.8% (37/123) completed an undergraduate degree. Of these, 91.9% (34/37) knew the meaning of the term zoonosis, with significant difference compared to those who were not trained. This word was unknown by 57% (29/123) of total respondents. Most non-graduates, 59.3% (51/86) did not know what is toxoplasmosis and among graduates, 35.1% (13/37) ignored the subject.There were significant difference between these groups. Regarding the prevention of Leishmania infection, a greater proportion of the residents advocated environmental cleanup, the collar repellent and use of citronella. In relation to toxoplasmosis, 54.5% did not know the ways of transmission of this disease and among those with graduate degree, 13 ignoring any transmission medium. When it comes to prevention of this disease, 55.3% (68/123) did not know any prophylactic. In the group of higher education, 14 did not know how to prevent toxoplasmosis. The results of this study show that the majority of respondents are not aware about the mode of transmission of these diseases, especially in relation to toxoplasmosis.

Clinical and epidemiological aspects of feline leishmaniasis in Brazil

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

Morphological, immunohistochemical and molecular study of renal lesions in canine visceral leishmaniasis (CVL)

Canine visceral leishmaniasis (CVL) is an anthropozoonosis characterized by a clinically chronic progressive disease. Non lymphoid organs are also affected, especially the kidneys. Dogs with leishmaniasis usually die with renal failure despite treatment. Haematoxylin-eosin (HE) staining in kidney tissue sections has low sensitivity for parasite identification. Immunohistochemistry (IHC) and polymerase chain reaction (PCR) are efficient methods for Leishmania sp. antigen and DNA detection in cases of low parasite burden. The present study aims to identify renal lesions of CVL and correlate them with microscopic findings determined by histochemistry, IHC and PCR. Both IHC and PCR provided similar positivity for amastigote identification, 3/20 animals (15%), thus increasing detection of the parasite in renal tissues when compared with histopathologic examination. The lesion most commonly observed with visceral leishmaniasis-positive canine kidney tissue was membranoproliferative glomerulonephritis, followed by interstitial nephritis without correlation to the number of amastigotes.