Lídia S. Oliveira

Investigação de áreas de risco como metodologia complementar ao controle da leishmaniose visceral canina

Risk areas of canine visceral leishmaniasis in the city of Camacari, Bahia, Brazil, were investigated. A total of 278 dogs from 141 homes pertaining to 20 investigated risk areas was serologically screened (ELISA). The general seroprevalence was 21.7% (56/258) after exclusion of 20 dogs used at the beginning of the survey to limit the study area. The respective results of the univariated and multivariated analysis of factors related to infection of dogs by Leishmania chagasi, to vector distribu-tion pattern in the area and to the methodology used to localize the canine focuses are discussed.

Headspace solid phase microextraction/gas chromatography-mass spectrometry combined to chemometric analysis for volatile organic compounds determination in canine hair: A new tool to detect dog contamination by visceral leishmaniasis

A new analytical methodology using HS-SPME/GC-MS was optimized in order to attain maximum sensitivity, using multivariate strategies. The proposed method was employed to evaluate the VOC profile exhaled from canine hair samples collected from 8 healthy dogs and from 16 dogs infected by Leishmania infantum. 274 VOCs were detected, which could be identified as aldehydes, ketones and hydrocarbons. After application of the Soft Independent Modeling of Class Analogy (SIMCA) and Principal Component Analysis (PCA) healthy and infected dogs, with similar VOCs profiles, could be separately grouped, based on compounds such as 2-hexanone, benzaldehyde, and 2,4-nonadienal. The proposed method is non-invasive, painless, readily accepted by dog owners and could be useful to identify several biomarkers with applications in the diagnosis of diseases.

Eletrocardiografia computadorizada em cães: estudo comparativo

O metodo de eletrocardiografia computadorizada (ECG-C) vem sendo crescentemente difundido na medicina veterinaria, havendo atualmente diversas marcas e modelos de eletrocardiografos disponiveis no mercado. Diante da possibilidade de diferencas na sensibilidade e na reprodutibilidade das medidas obtidas nos tracados, o presente estudo teve como objetivo comparar os parâmetros eletrocardiograficos de caes, obtidos por dois sistemas. Foram avaliados dois diferentes softwares computadorizados, o Wincardio Micromed® (WIN) e o modelo TEB ECGPC® (TEB). Quarenta e dois caes higidos, de diferentes racas (Cocker Spaniel, Daschund, Labrador, Pinscher, Pit Bull Terrier Poodle, Schnauzer, Shit Tzu, Yorkshire e sem raca definida), machos e femeas e com idade entre 4 meses e 16 anos foram agrupados segundo o peso e examinados pelos dois sistemas. As medidas eletrocardiograficas dos diferentes tracados foram analisadas na derivacao DII. Os resultados indicaram que o sistema TEB apresentou maior sensibilidade na obtencao das medidas de duracao da onda P e do complexo QRS, enquanto o sistema WIN foi mais sensivel para determinar as medidas de amplitude dos mesmos parâmetros. Os animais de maior porte (26-37kg) apresentaram maior variância nas medidas de duracao e amplitude de onda P e duracao do complexo QRS em comparacao aos caes de medio (14-25kg) e pequeno (1-13kg) porte. O achado de diferencas entre os sistemas testados deve ser levado em consideracao ao se empregar os diversos equipamentos para diagnostico por meio de ECG-C na rotina clinica, de modo a evitarem-se divergencias na interpretacao dos exames entre diferentes prestadores de servicos veterinarios.

Teste de ELISA indireto para diagnóstico sorológico de leishmaniose visceral em canídeos silvestres

In South America, some wild canids are considered natural reservoirs of Leishmania chagasi. The immunological response of wild canids to Leishmania is not well understood, and the development of diagnostic methods is necessary for such purpose. In the present study, the standardization of an enzyme-linked immunosorbent assay (ELISA) for the serodiagnosis of visceral leishmaniasis (VL) in Brazilian species of wild canids is described. Serum and plasma samples from 12 captive wild canids were studied: seven from maned wolves (Chrysocyon brachyurus), three from hoary foxes (Lycalopex vetulus), and two from crab-eating foxes (Cerdocyon thous). Samples from C. brachyurus and L. vetulus, both captive in an endemic area for VL, presenting clinical disease and positivity in Indirect Immunofluorescence Reaction and Polymerase Chain Reaction tests were used as positive controls. The antibody anti-dog IgG and Protein A, both conjugated with horseradish peroxidase, were compared in indirect ELISA tests which detected four (04/12) and three (03/12) seropositive C. brachyurus for anti-Leishmania antibodies, respectively. The ELISA tests were able to clearly distinguish negative from positive samples, as the mean optical density (OD) of the negative samples was 4.8 and 15.5 times lower than those of the positive ones either using anti-dog IgG and Protein A, respectively. Samples from three ELISA - positive C. brachyurus were analyzed by Western blotting and identified immunodominant bands of 19, 22, 24, 45 and 66 kDa, among 22 protein bands detected. The ELISAs with protein A and anti-dog IgG showed respectively excellent (Kappa = 1.0; p<0.001) and moderate (Kappa = 0.8; p<0.0015) agreement with the Western blotting assay. The ELISA tests showed to be adequate for screening studies to identify antibody responses, thus indicating contact with Leishmania infection by wild canids.