Trypanocidal activity of human plasma on Trypanosoma evansi in mice.

This study aimed to test an alternative protocol with human plasma to control Trypanosoma evansi infection in mice. Plasma from an apparently 27-year-old healthy male, blood type A+, was used in the study. A concentration of 100 mg.dL(-1) apolipoprotein L1 (APOL1) was detected in the plasma. Forty mice were divided into four groups with 10 animals each. Group A comprised uninfected animals. Mice from groups B, C and D were inoculated with a T. evansi isolate. Group B was used as a positive control. At three days post-infection (DPI), the mice were administered intraperitoneally with human plasma. A single dose of 0.2 mL plasma was given to those in group C. The mice from group D were administered five doses of 0.2 mL plasma with a 24 hours interval between the doses. Group B showed high increasing parasitemia that led to their death within 5 DPI. Both treatments eliminated parasites from the blood and increased the longevity of animals. An efficacy of 50 (group C) and 80% (group D) of human plasma trypanocidal activity was found using PCR. This therapeutic success was likely achieved in the group D due to their higher levels of APOL1 compared with group C.

Trypanocidal activity of human plasma on Trypanosoma evansi in mice / Atividade tripanocida do plasma humano sobre Trypanosoma evansi em camundongos

This study aimed to test an alternative protocol with human plasma to control Trypanosoma evansi infection in mice. Plasma from an apparently 27-year-old healthy male, blood type A+, was used in the study. A concentration of 100 mg.dL-1 apolipoprotein L1 (APOL1) was detected in the plasma. Forty mice were divided into four groups with 10 animals each. Group A comprised uninfected animals. Mice from groups B, C and D were inoculated with a T. evansi isolate. Group B was used as a positive control. At three days post-infection (DPI), the mice were administered intraperitoneally with human plasma. A single dose of 0.2 mL plasma was given to those in group C. The mice from group D were administered five doses of 0.2 mL plasma with a 24 hours interval between the doses. Group B showed high increasing parasitemia that led to their death within 5 DPI. Both treatments eliminated parasites from the blood and increased the longevity of animals. An efficacy of 50 (group C) and 80% (group D) of human plasma trypanocidal activity was found using PCR. This therapeutic success was likely achieved in the group D due to their higher levels of APOL1 compared with group C.

Este estudo teve como objetivo testar um protocolo alternativo com plasma humano para controlar a infecção por Trypanosoma evansi em camundongos. O plasma foi oriundo de um homem aparentemente saudável, com idade entre 27 anos e tipo de sangue A+. Foi detectada uma concentração de 100 mg.dL -1 de apolipoproteína L1 (APOL1) no plasma. Quarenta camundongos foram divididos em quatro grupos, contendo dez animais cada. Grupo A, composto de animais não infectados. Os roedores dos grupos B, C e D foram inoculados intraperitonealmente com um isolado de T. evansi. O Grupo B foi usado como um controle positivo. Três dias pós-infecção (DPI), os camundongos foram tratados com plasma humano. Uma dose única de 0,2 mL de plasma foi administrada nos roedores do grupo C. Os ratos do grupo D receberam cinco doses de 0,2 mL de plasma em intervalos de 24 horas. Os ratos do grupo B apresentaram parasitemia crescente, o que ocasionou a morte dos animais em 5 DPI. Ambos os tratamentos foram capazes de eliminar o parasito do sangue e aumentar a longevidade dos animais. O método da PCR detectou uma eficácia de 50% (grupo C) e 80% (grupo D) no tratamento com plasma humano. Este sucesso terapêutico obtido nos animais do grupo D provavelmente foi por receber maiores níveis de APOL1, comparado ao grupo C.

Susceptibility of Trypanosoma evansi to human blood and plasma in infected mice.

Around 1900 Laveran and Mesnil discovered that African trypanosomes do not survive in the blood of some primates and humans. The nature of the trypanolytic factor present in these sera has been the focus of a long-standing debate between different groups. The aim of this study was to investigate the susceptibility of T. evansi isolates to therapy using human blood and plasma in experimentally infected mice. Forty-eight 2-month-old female mice (Mus musculus) were divided into six groups of eight animals per group (A, B, C, D, E and F). Plasma was obtained after blood collection in order to perform therapy. Animals from group A (positive control) were inoculated with T. evansi and treated with 0.2mL of saline solution. Animals from groups B and C were infected with the flagellate and received a curative treatment with 0.2mL of human blood (group B) and 0.2mL of human plasma (group C), 24h after infection. Animals from groups D and E received a prophylactic treatment with 0.2mL of human blood and 0.2mL of human plasma, respectively, 24h prior to the infection. Animals from group F (negative control) were not infected and received 0.2mL of saline solution. The four treatments (B, C, D and E) increased animals longevity when compared to group A. Prepatency period was longer in groups D (15 days) and E (37.7 days) under prophylactic immunotherapy. Moreover, no parasites were found in most of the animals 60 days post-inoculation (PI). Besides the longer longevity, treatments were capable of curing 50% of mice of group B, 37.5% of group C, 37.5% of group D and 25% of the animals from group E.

Patogenicidade de um isolado de Trypanosoma evansi em ratos inoculados com o parasito em sangue in natura e criopreservado / Trypanosoma evansi pathogenicity strain in rats inoculated with parasite in fresh and cryopreserved blood

O objetivo deste estudo foi investigar a patogenicidade do isolado de Trypanosoma evansi (LPV-2005), em ratos (Rattus norvergicus), sob influência da imunidade passiva, de diferentes concentrações e de meios de conservação. Para tanto, foram utilizados 36 Rattus norvergicus, fêmeas, separados em seis grupos homogêneos. Os roedores dos grupos A e B foram infectados com 10(5) T. evansi, e os animais dos grupos C e D foram infectados com 10(6) tripomastigotas/animal. Os grupos E e F foram utilizados como grupo controle negativo, isto é, inoculados com sangue in natura e criopreservado sem o parasito, respectivamente. O grupo A foi formado por ratos filhos de fêmeas infectadas com protozoário, mas curadas após tratamento. Os grupos B, C e D continham roedores que nunca tiveram contato com o isolado LPV-2005. Os grupos B e C diferiram quanto à dose inoculada do flagelado mantida em cultura viva (ratos Wistar). Já os ratos do grupo D foram infectados com sangue criopreservado em nitrogênio líquido. A patogenicidade do isolado foi avaliada a partir do período pré-patente, da evolução da parasitemia e da longevidade dos animais. O grupo D apresentou um período pré-patente superior aos demais grupos. Em relação à longevidade dos animais de cada grupo, foi verificada diferença estatística significativa (P<0,05). O grupo D apresentou um período de vida de 27,8 dias, e o grupo C, de apenas 4,8 dias. Os ratos de ambos os grupos controle mantiveram-se vivos por 50 dias, quando foram eutanasiados. Portanto, a preservação do inóculo testado e a dose infectante de T. evansi influenciam a patogenicidade do isolado LPV-2005 para ratos. A presença de anticorpos maternos em ratos não impede a infecção e mortalidade por T. evansi.

This study aimed to evaluate the Trypanosoma evansi strain pathogenicity (LPV-2005) in rats under passive immunity influence, of different concentrations and media preservation. Thirty six adult female Rattus norvergicus were separated in six equal groups. Groups A and B were inoculated with 10(5) T. evansi and groups C and D with 10(6) blood trypomastigotes per animal. Groups E and F were used as negative control in which the animals were inoculated with fresh and cryopreserved blood, without the parasite. Group A were composed of T. evansi infected born rats and cured females. Groups B, C and D were composed with animals never exposed to the LPV-2005 strain. All groups B and C animals received different doses of blood trypomastigotes kept in Wistar rats, while animals from group D were infected with cryopreserved blood kept in liquid nitrogen. The the strain pathogenicity was estimated by prepatency evaluation period, levels of parasitemia and animals longevity. Group D showed a longer prepatency period in comparison with other groups. The longevity of group D (27.8 days) was significantly different (P<0.05) from group C (4.8 days). Rats of the control group were euthanized 50 days postinfection. In conclusion, the tested inoculum-preservation methods and the infective dose of T. evansi influenced the pathogenicity of the LPV-2005 strain in rats. The presence of maternal antibodies did not prevent the infection and mortality of the rats by T. evansi.

Duddingtonia flagrans: centrifugal flotation technique with magnesium sulphate for the quantification and qualification of chlamydospores in sheep faeces.

Duddingtonia flagrans is a nematode-trapping fungus responsible for attacking larval stages of helminths in pasture, which has potential as a biological control method. The aim of this study was to test the magnesium sulphate centrifugal flotation technique for the quantification of D. flagrans chlamydospores in sheep faeces and to verify their morphological viability. In this experiment one sheep received an oral dose of 4.5 x 10(6) chlamydospores/day during 20 days. Fecal samples were collected between days 15 and 20 and analyzed by the centrifugal flotation technique with magnesium sulphate. Densities of 1.23, 1.27 and 1.31gmL(-1) recovered 1.45 x 10(5), 3.87 x 10(5) and 1.65 x 10(5) chlamydospores from the faeces, respectively. Based upon the results it was concluded that this is an efficient technique for the chlamydospores quantification in ovine faeces. Moreover, it allowed more accurate visualization of chlamydospore morphology.

[Accidental myiasis by Ornidia obesa in humans]. / Miíase acidental por Ornidia obesa em humanos.

Dipterous of the genus Ornidia are pollinator bugs, but immature stages can be found in organic matter in decomposition. This article refers to a found of larvae of Ornidia obesa in humans feces. An eight years old child was treated in a medical clinic due to the presence of two larvae and one pupae in the feces, hyperthermia, intestinal obstruction and strong abdominal pain. Medical therapy consisted of Mebendazol and Ivermectin in the indicated doses. 24 hours after the administration of the drugs, several larvae were expelled with diarrheic feces. The material was taken to the Parasitological Veterinary Lab, and the larvae were classified belonging to the genus Ornidia. According to the literature, this specie of Diptera is not incriminated to cause myiasis in vertebrates. We think that this study reports a case of accidental myiasis in humans, were the patient may have ingested food with immature stages of the fly (eggs or larvae).

Primeiro registro de parasitismo por Giardia sp. em Leopardus geoffroyi (gato-do-mato-grande) mantido em cativeiro / First record of parasitism by giardia sp. in leopardus geoffroyi (geoffroy’s cat) kept in captivity

Este estudo visou registrar o parasitismo por Giardia sp. em gatos-do-mato-grande (L. geoffroyi), mantidos em cativeiro na região sul do Brasil. Foram analisadas amostras de fezes de dois gatos do mato, machos, sendo um adulto e outro jovem. As amostras foram armazenadas sob refrigeração até serem processadas em laboratório, através do método de centrífugo-flutuação, com sulfato de zinco. No exame de fezes de ambos os animais, observou-se infecção por cistos do gênero Giardia, no entanto, os felinos não apresentaram sinais clínicos decorrentes da enfermidade.

This study aimed to register the parasitism by Giardia sp. in Geoffroy’s cats (L. geoffroyi) kept in captivity in the Southern region of Brazil. Fecal samples from one adult and one young male Geoffroy’s cat were collected. Samples were maintained refrigerated until being processed in laboratory through the zinc sulphate centrifugal-flotation method. Assay of feces from both animals showed infection by cysts of Giardia, although the felines did not present any clinical signs associated to the disease.

Este estudio tuvo por objeto observar el parasitismo por Giardia sp. en gato montés (L. geoffroyi) mantenidos en cautiverio en la región sur de Brasil. Fueron analizadas muestras de heces de dos gatos de esta especie, machos, siendo un adulto y otro joven. Las muestras fueron almacenadas bajo refrigeración hasta que fuesen procesadas en laboratorio, a través del método de centrifugo-flotación con sulfato de zinc. En el examen de heces de ambos los animales se observó infección por quistos del género Giardia sp, sin embargo, los felinos no presentaron señales clínicos en virtud de la enfermedad.