Histopathological and ultrastructural findings induced by heat-inactivated Lactobacillus plantarum and the culture supernatant on the intestinal mucosa of piglets: an ex vivo approach / Achados histopatológicos e ultraestruturais induzidos por Lactobacillus plantarum inativado pelo calor na mucosa intestinal de leitões: estudo ex-vivo

In the present study, histological, morphometrical and ultrastructural analysis were performed to investigate intestinal mucosa changes in piglets jejunal explants exposed to two concentration of heat-inactivated Lactobacillus plantarum and their respective culture supernatants. Jejunal explants were incubated for 4 hours in DMEM culture medium with a) only culture medium (control group), b) heat-inactivated Lactobacillus plantarum strain1 - LP1 (1.1 x 108CFU/ml), c) heat-inactivated Lactobacillus plantarum strain2 - LP2 (2.0 x 109CFU/ml), d) heat-inactivated Lactobacillus plantarum strain1 culture supernatant (CS1), and e) heat-inactivated Lactobacillus plantarum strain2 culture supernatant (CS2). Explants exposed to heat-inactivated L. plantarum strain 1 and 2 showed multifocal to difuse villi atrophy, villi apical necrosis and enterocyte flattening. Morphological assessment revealed similar results with bacterial adhesion to mucus and intestinal epithelial cells and, morphometric analysis showed a decreased villi height compared to the control group. Alterations in explants treated with the culture supernatant of both strains include mild villi atrophy and mild enterocyte apical necrosis. Morphological assesment reveled numerous well delineated villi and, morphometric analysis showed a significant increase in villi height compared to the control group. In general, exposure to the culture supernatants improved the intestinal morphology.(AU)

No presente estudo, foram realizadas análises histológica, morfométrica e ultraestrutural para investigar as alterações da mucosa intestinal em explantes jejunais de leitões expostos a duas cepas e concentrações de Lactobacillus plantarum inativado pelo calor e seus sobrenadantes de cultura. Os explantes jejunais foram incubados durante quatro horas, em meio de cultura DMEM com: a) meio de cultura (grupo controle); b) Lactobacillus plantarum, cepa 1 - LP1 (1,1 x 108CFU/mL); c) Lactobacillus plantarum, LP2 (2,0 x 109CFU/mL); d) sobrenadante da cultura do Lactobacillus plantarum, cepa 1 (SC1); e e) sobrenadante da cultura do Lactobacillus plantarum, cepa 2 (SC2). Os explantes expostos às cepas 1 e 2 do L. plantarum inativado pelo calor mostraram atrofia difusa de vilosidades, necrose apical das vilosidades e achatamento de enterócitos. A avaliação morfológica revelou resultados semelhantes, com adesão bacteriana ao muco e às células epiteliais intestinais, e a análise morfométrica mostrou uma diminuição da altura das vilosidades em relação ao grupo controle. Alterações nos explantes tratados com o sobrenadante da cultura de ambas as cepas caracterizaram-se por atrofia leve das vilosidades e necrose apical leve dos enterócitos. A avaliação morfológica revelou vilosidades bem delineadas, e a análise morfométrica mostrou um aumento significativo na altura das vilosidades em comparação ao grupo controle. Em geral, a exposição aos sobrenadantes da cultura melhora a morfologia intestinal.(AU)

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.