Inflammatory response, parasite load and AgNOR expression in ear skin of symptomatic and asymptomatic Leishmania (Leishmania) chagasi infected dogs

The skin has an important role in the transmission of visceral leishmaniasis (VL) as the infection pathway in dogs. To better characterize the inflammatory response of intact skin in VL, sixty infected dogs (30 symptomatic and 30 asymptomatic) and six non-infected controls were studied. Diagnosis of visceral leishmaniasis was confirmed by RIFI and ELISA; direct visualization of the parasite in bone marrow aspirate; imprints of popliteal lymph nodes, spleen, liver and skin; culture in NNN-phase liquid Schneider's medium; and PCR (performed only in the ear skin). Amastigote forms of the parasite in intact skin were found only in symptomatic dogs. Inflammatory infiltrates were observed in all groups, varying from intense and/or moderate in symptomatic to discrete and/or negligible in asymptomatic and control animals. Parasite load was associated with the intensity of the inflammatory response and with clinical manifestations in canine visceral leishmaniasis. AgNOr as active transcription markers were expressed in inflammatory cells and within apoptotic bodies in all groups, including controls, with no statistical difference. Therefore, cell activation and transcription do occur in both symptomatic and asymptomatic canine visceral leishmaniasis and may result in more necrosis and inflammation or in apoptosis and less symptoms, depending on the parasite load.

Cardiac and pulmonary alterations in symptomatic and asymptomatic dogs infectednaturally with Leishmania (Leishmania) chagasi

Fifteen symptomatic and seven asymptomatic dogs infected naturally with Leishmania chagasi were examined in order to identify the presence of parasites and changes in heart and lung. Histopathological, cytological, and immunohistochemical analyses were performed on samples of heart and lung tissues. An inflammatory reaction characterized by inflammatory mononuclear, perivascular and intermuscular infiltrates was observed in both symptomatic and asymptomatic animals on histopathological analysis of the heart. In the lung, there was thickening of the alveolar septa due to congestion, edema, inflammatory infiltrate, and fibroblast proliferation. A focal reaction was observed although a diffuse reaction was present in both groups. On cytological examination, heart and lung imprints revealed amastigotes in two symptomatic animals and heart imprints were found in 1 asymptomatic dog. Immunoperoxidase staining showed amastigotes in the lung and heart of only 1 of 6 symptomatic animals examined. Within the ethical principles and limits of this research, it can be inferred that the study of heart and lung alterations in canine visceral leishmaniasis is increasingly important for understanding the problem related to humans. Dogs with visceral leishmaniasis were a good experimental model, since infection was caused by the same agent and the animals developed clinical, pathological and immunological alterations similar to those observed in humans.

Pesquisa de sorovares de leptospiras em rebanho bovino leiteiro no estado do Piauí, Brasil / Survey of leptospira serovars in a dairy cattle herd in Piauí state, Brazil

Este trabalho teve como objetivo relatar a pesquisa de sorovares de leptospiras em animais de uma fazenda localizada no Município de Buriti dos Lopes, integrante da Bacia Leiteira de Parnaíba, Piauí, Brasil. Foram colhidas amostras de sangue de 18 vacas da raça Girolando que abortaram no período de julho de 2004 a abril de 2005. As amostras foram submetidas ao teste de soroaglutinação microscópica (SAM) utilizando-se antígenos vivos de 23 sorovares de leptospiras patogênicas. 83,33% (15/18) das amostras apresentaram aglutininas anti-leptospira, sendo 53,33% de sorovar Hardjoprajitno (8/15), 6,67% para Hardjobovis (1/15), Wolffi (1/15) e Shermani (1/15) e quatro (4/15) co-agluitinações. A amostra do reprodutor apresentou aglutininas antileptospira para o sorovar Hardjobovis com titulação 1:400 o que sugere que este animal teve participação na disseminação da infecção no rebanho.

This study aimed to report the leptospira serovar varieties in animals from a farm located in the county of Buriti dos Lopes, within the so-called "milk basin" of Parnaíba, state of Piauí, Brazil. Samples of blood were collected from 18 Girolando cows who aborted between July 2004 and April 2005, and a sample was taken from a breeder bull. The samples were subjected to the microscopic agglutination test (SAM), using live antigens of 23 pathogenic leptospira serovars. Serum samples were screened in the dilution of 1:100. Data analysis revealed that 83.33% (15/18) of the samples showed anti-leptospira agglutinins, of which 53.33% were for the Hardjoprajitno serovar (8/15), 6.67% each for Hardjobovis (1/15), Wolffi (1/15) and Shermani (1/15), along with 4 (4/15) coagglutinations. The breeder-bull sample showed anti-leptospira agglutinins for serovar Hardjobovis with titration of 1:400, suggesting that this animal had participated in the spread of the infection in the herd.

Infecção por leptospira em bovinos e sua associação com transtornos reprodutivos e condições climáticas / Leptospiral infection in bovine and its association with reproductive failure and climatic conditions

Realizou-se estudo sorológico, por meio do teste de soroaglutinação microscópica, utilizando antígenos vivos, para pesquisa de aglutininas anti-leptospiras em bovinos de leite na Microrregião de Parnaíba, PI, em dois períodos do ano: estações seca e chuvosa. Das 1975 amostras analisadas, pertinentes a 16 rebanhos, 1044 (52,9 por cento) mostraram-se positivas a pelo menos um sorovar e todos os rebanhos apresentaram animais reagentes. A prevalência variou entre 25 por cento e 81 por cento. O sorovar de maior prevalência foi Hardjo reagindo em 39,5 por cento, seguido de Wolffi com 26,7 por cento e Hebdomadis com 12,2 por cento. Os sorovares mais freqüentes foram Hardjo e Wolffi presentes em 100 por cento dos rebanhos. Foram ainda encontrados animais reagentes aos sorovares Australis, Bratislava, Autumnalis, Butembo, Icterohaemorrhagiae, Shermani e Patoc. Houve correlação positiva entre a proporção de animais sororreagentes para leptospirose e pluviometria, mas não para temperatura. Foi constatada associação entre infecção e ocorrência de transtornos reprodutivos, e o sorovar que apresentou maior associação foi o Hardjo

This study was carried out by serologic sampling (microscopic agglutination test, living antigens) for anti-leptospiral antibodies in dairy farms of Parnaíba microrregion, state of Piauí, Brazil, during dry and rainny seasons. All 16 flocks were infected and 1044 out of 1975 sera samples (52.9 percent) were positive for at least one serovar. Higher prevalence was serovar Hardjo (39.5 percent) folowed by Wolffi (26.7 percent) and Hebdomadis (12.2 percent). Hardjo and Wolffi were found in all flocks. Serovars Australis, Bratislava, Autumnalis, Butembo, Hebdomadis, Icterohaemorrhagiae, Hardjo, Wolffi, Shermani and Patoc, were also present. A positive correlation between prevalence of infection and pluviometric was detected, but temperature ratios. Association between infection and reproductive failures was evidenced mainly regarding Hardjo serovar

Leishmania (Leishmania) chagasi-infected mice as a model for the study of glomerular lesions in visceral leishmaniasis

Renal involvement in visceral leishmaniasis (VL) is very frequent but the pathogenesis of this nephropathy is poorly understood. In previous studies using dogs with VL we have detected new immunopathological elements in the glomeruli such as T cells and adhesion molecules. Although Leishmania (Leishmania) chagasi-infected dogs and hamsters are considered to be good models for VL, their use is limited for immunopathologic studies. The use of isogenic mouse strains susceptible to L. (L.) chagasi infection was an alternative but, on the other hand, the renal lesions of these animals have not yet been characterized. Thus, our purpose in the present study was to characterize mice infected with L. (L.) chagasi as a suitable model to study VL nephropathy. Kidney samples were obtained from control mice (N = 12) and from BALB/c mice (N = 24) injected intraperitoneally with 20 million L. (L.) chagasi amastigotes 7, 15, and 30 days after injection and processed for histopathological studies and detection of IgG deposits. Glomerular hypercellularity was clearly visible and, upon Mason's trichrome and periodic acid methenamine silver staining, a pattern suggestive of mesangial proliferative glomerulonephritis was observed in mice with VL. Time-dependent IgG deposits were also seen in infected mice. We consider L. (L.) chagasi-infected mice to be a suitable model for studies of the immunopathogenesis of glomerular lesions in VL.

Detection of immunoglobulin G in the lung and liver of hamsters with visceral leishmaniasis

Several organs are affected in visceral leishmaniasis, not only those rich in mononuclear phagocytes. Hypergammaglobulinemia occurs during visceral leishmaniasis; anti-Leishmania antibodies are not primarily important for protection but might be involved in the pathogenesis of tissue lesions. The glomerulonephritis occurring in visceral leishmaniasis has been attributed to immune complex deposition but in other organs the mechanism has not been studied. In the current study we demonstrated the presence of IgG in the lung and liver of hamsters with visceral leishmaniasis. Hamsters were injected intraperitoneally with 2 x 10(7) amastigotes of Leishmania (Leishmania) chagasi and the presence of IgG in the liver and lung was evaluated at 7, 15, 30, 45, 80 and 102 days postinfection (PI) by immunohistochemistry. The parasite burden in the spleen and liver increased progressively during infection. We observed a deposit of IgG from day 7 PI that increased progressively until it reached highest intensity around 30 and 45 days PI, declining at later times. The IgG deposits outlined the sinusoids. In the lung a deposit of IgG was observed in the capillary walls that was moderate at day 7 PI, but the intensity increased remarkably at day 30 PI and declined at later times of infection. No significant C3 deposits were observed in the lung or in the liver. We conclude that IgG may participate in the pathogenesis of the inflammatory process of the lung and liver occurring in experimental visceral leishmaniasis and we discuss an alternative mechanism other than immune complex deposition

CD4+ T cells participate in the nephropathy of canine visceral leishmaniasis

Renal involvement in visceral leishmaniasis (VL) is very frequent. The renal lesions of humans and dogs are similar but their pathogenesis has not been clearly elucidated. There is growing evidence that the cellular immune response is involved in the pathogenesis of immunologically mediated glomerulonephritis. Since T cells could participate in the pathogenesis of nephropathy, in the present study we investigated the possible involvement of CD4+ and CD8+ T cells in the nephropathy of canine VL. Six dogs naturally infected with Leishmania (Leishmania) chagasi from the endemic area in the Northeast of Brazil, the town of Teresina in the State of Piauí, were studied. An expressive inflammatory infiltrate of CD4+ T cells both in glomeruli and in interstitium was present in 4 animals and absent in 2. CD8+ T cells were detected only in one animal. CD4+ T cells alone were observed in 3 animals; when CD8+ T cells were present CD4+ T cells were also present. CD4+ T cells were observed in cases of focal segmental glomerulosclerosis, diffuse membranoproliferative glomerulonephritis, diffuse mesangial proliferative glomerulonephritis and crescentic glomerulonephritis. CD8+ T cells were present only in a case of crescentic glomerulonephritis. Leishmania antigen was detected in glomeruli and in interstitial inflammatory infiltrate in 4 animals and immunoglobulins were observed in 4 dogs. In this study we observed that T cells, in addition to immunoglobulins, are present in the renal lesion of canine VL. Further studies are in progress addressing the immunopathogenic mechanisms involving the participation of immunoglobulins and T cells in canine VL nephropathy

Gestaçäo ectópica abdominal primária em cadela / Primary abdominal ectopic pregnancy in bitch

O exame necroscópico de uma cadela mestiça (pequinês), adulta, sem idade definida, proveniente do canil do Centro de Ciências Agrárias daUniversidade Federal do Piauí que foi destinada casualmente para aula prática dadisciplina de Patologia Animal, revelou a presença de dois fetos, aparentemente a termo, na cavidade abdominal, envoltos por cápsula conjuntiva bem vascularizada contendo líquido aquoso de coloraçäo amarelada e, localizados no omento gastro-esplênico. Os fetos apresentavam-se íntegros, medindo 14 e 11 cm de comprimento, com estruturas aparentes bem desenvolvidas, inclusive com superfície corporal recoberta de pelos e unhas bem formadas. O útero näo revelava sinais de ruptura,bem como näo existia qualquer evidência de ligaçäo entre esse órgäo e os fetos. Esses achados demonstraram tratar-se de um caso raro de gestaçäo ectópica abdominal primária em cadela