Toxocariasis, caused most commonly by Toxocara canis, is an important cosmopolitan zoonosis. Paratenic hosts have been employed to provide knowledge regard to the transmission of toxocariasis. Transmammary transmission in murine experimentally infected was observed based on the recovery of larvae from the tissue. The aim of this study was to evaluate the possibility of transmammary transmission of Toxocara canis in rabbits by detecting larvae directly in milk. Seventeen sexually mature virgin white New Zealand female rabbits were divided into two groups. Twelve animals were orally inoculated with 1,000 T. canis embryonated eggs (infected group), and five animals remained uninfected (control group). One month following the infection, the females were mated. Manual collection of 500 µL of milk from each rabbit was performed on days +7, +14 and +21 of lactation for three consecutive lactations. The recovery of larvae was determined via a centrifuge-sedimentation technique using ether and formalin solutions. ELISA test was run to confirm the production of anti-T. canis antibodies (IgG) by infected rabbits. The presence of larvae was observed in milk samples from 5 (41.7%) of the 12 infected rabbits. The total number of recovered larvae was 20, ranging from 1 to 4 larvae per lactation/rabbit. Larvae were recovered exclusively on days 7 and 14 of lactation. Recovery was verified in different lactations. No significant difference was observed with respect to the number of larvae either in the same lactation period or in different lactation periods. Anti-T. canis antibodies were detected in all infected rabbits. In conclusion, the presence of larvae in rabbit milk samples suggests the possibility of galactogenic transmission of T. canis in paratenic hosts. Moreover, the technique employed in this study allows for the recovery of larvae directly from milk. a recuperação de larvas. O objetivo do presente estudo foi de avaliar a possibilidade de transmissão transmamária de Toxocara canis em coelhos, pela detecção direta de larvas no leite. Dezessete coelhas (Nova Zelândia branca) púberes e virgens foram distribuídas em dois grupos. Doze fêmeas foram infectadas com 1000 ovos embrionados de T. canis (Grupo Infectado), por via oral, enquanto outras cinco coelhas foram mantidas sem infecção (Grupo Controle). Um mês após a inoculação, as coelhas foram acasaladas. Nos dias +7, +14 e +21 após o nascimento dos filhotes, foram coletados, por ordenha manual, 500µL de leite, em três lactações consecutivas. A recuperação de larvas foi determinada pelo uso da técnica de centrífugo-sedimentação com formol-éter. A técnica de ELISA foi empregada para confirmar a produção de anticorpos (IgG) anti-T. canis pelas fêmeas infectadas. Observou-se a presença de larvas em cinco das doze (41,7%) coelhas por amostra. As larvas foram recuperadas exclusivamente nos dias +7, +14 de lactação. A detecção foi observada em diferentes lactações. Não houve diferença significativa entre o número de larvas na mesma lactação ou entre as diferentes lact...

This study aimed to evaluate the limit of detection of Toxocara canis larvae in experimentally contaminated commercial bovine milk samples, based on a centrifuge-sedimentation technique. Firstly, bovine milk (whole and skim) samples were contaminated with 50 T. canis larvae in order to evaluate the interference of milk fat with the recovery of the larvae. Next, the effects of 10% formalin (100 µL), ether (100 µL), and a combination of both solutions on the recovery of the larvae was examined. Thereafter, the limit of detection of the larvae was determined using the solution (from step 2) considered optimal for degreasing the milk sample. Samples were contaminated with aliquots of 1, 5, 10, 25, and 50 larvae. For each milk sample (1.0 mL), 15 repetitions were analysed. The recovery of the larvae from the skim milk samples was higher (p = 0.0031) than that from the whole milk samples. No significant difference (p = 0.5681) was observed with regard to the percentage of recovered larvae when comparing the degreasing solutions. Nevertheless, the formalin-ether combination was more efficient for recovering the larvae (73.1%) than ether (71.9%), formalin (67.6%), and pure whole milk (70.0%). Concerning the limit of detection (using formalin-ether), all the samples contaminated with 5, 10, 25, and 50 larvae tested positive (minimum: 62.7%). Of the samples contaminated with a single larva, 66.7% tested positive. These results suggest that the centrifugation-sedimentation technique may be useful for recovering larvae of Toxocara spp. in naturally or experimentally contaminated milk samples obtained from a wide range of animal species. Key words: Toxocariasis, recovery of larvae, diagnosis ResumoO objetivo do estudo foi avaliar o limite de detecção de larvas de Toxocara canis em leite bovino comercial contaminado experimentalmente, a partir de uma técnica de centrifugo-sedimentação. Primeiramente, amostras de leite bovino comercial (integral e desnatado) foram contaminadas com 50 larvas de T. canis, para avaliação da interferência da gordura sobre a recuperação das larvas. Em uma segunda etapa, foi avaliada a ação de formalina 10% (100 µL), éter (100 µL) e combinação das soluções. A terceira etapa consistiu da verificação do limite de detecção de larvas, com uso da melhor solução desengordurante (etapa 2), em amostras de leite (1,0 mL) contendo 1; 5; 10; 25 e 50 larvas. Para cada análise de detecção do leite (1,0 mL), foram realizadas 15 repetições. Foi observado que o percentual de recuperação de larvas no leite desnatado foi significativamente maior (p= 0,0031) que o observado no leite integral. Na comparação das soluções, não houve diferença significativa (p= 0,5681) no percentual de larvas recuperadas. Entretanto, houve uma maior recuperação quando do emprego da combinação de formol-éter (73,1%) em relação ao éter (71,9%), ao formol (67,6%) e ao leite integral puro (70,0%). Em relação ao limite de detecção, com uso de formalina-éter, todas as alíquotas apresentaram resultado positivo (mínimo de 62,7% de larvas ...

An evaluation was made of the kinetics and avidity of anti-Toxocara antibodies (IgG) in rabbits experimentally infected with embryonated Toxocara canis eggs. Seventeen four month old New Zealand White rabbits were distributed into two groups. In the experimental group, twelve rabbits were infected orally with 1,000 embryonated T. canis eggs. A second group (n = 5), uninfected, was used as a control. Serum samples were collected for analysis on days 7, 14, 21, 28 and 60 post-infection (DPI). An indirect ELISA test was performed to evaluate the reactivity index (RI) of IgG anti-T. canis antibodies and to calculate the avidity index (AI). The animals showed seroconversion from the 14 th DPI, with high AI (over 50%) except for one animal, which presented an intermediate AI. At 60 DPI, all the animals were seropositive and maintained a high AI. The data indicated that specific IgG antibodies formed early (14 DPI) in rabbits infected with T. canis, with a high avidity index that persisted throughout the course of the infection.

No abstract

O objetivo deste estudo foi comparar os resultados de três exames de diagnóstico para dermatofitose em 71 cães e cinco gatos com lesões de pele: microscopia direta, cultura de fungos e fluorescência à lâmpada de Wood. A concordância entre os três testes foi avaliada pela estimativa do coeficiente Kappa. A sensibilidade e a especificidade dos testes de microscopia direta e fluorescência foram calculadas com base nos resultados das culturas de fungos. Dos 76 cães e gatos avaliados, 18 (23,6%) tiveram culturas positivas. As espécies de fungos isoladas foram Microsporum canis (88,8%), Microsporum gypseum (5,5%) e Trichophyton mentagrophytes variedade mentagrophytes (5,5%). A estimativa dos coeficientes Kappa indicou concordância fraca entre os três métodos diagnósticos. A sensibilidade da microscopia direta e fluorescência em lâmpada de Wood foram respectivamente 64,71% e 41,18% e especificidade de 27,12% e 66,10%, respectivamente. Considerando as conseqüências dos resultados falso-positivos e falso-negativos para o diagnóstico das dermatofitoses, é recomendado não usar esses três testes separadamente, mas combiná-los para obter resultados mais confiáveis. Palavras -chave: dermatofitoses, animais de estimação, testes diagnósticos, zoonose, dermatologia COMPARATIVE STUDY OF DIAGNOSTIC METHODS