No abstract

Leishmania modified the quantity of cells in and morphology of mice ilea.

Evaluating the histopathological and morphometric changes caused by Leishmania (Leishmania) infantum chagasi infection either in the presence or absence of B‐1 cells. Wild‐type Balb/c and XID mice were used. Half of XID mice received B‐1 cells adoptive transfer (XID + B1). Five animals from each group were infected (Balb/c I, XID I and XID + B1 I), totalizing six groups (n = 5). After 45 days of infection, the ileum was collected for histological processing and analysis. After infection, the XID animals showed an increase in the thickness of the intestinal layers, in the depth and width of the crypt and in the villi width. However, the Balb/c I group showed a reduction in almost all these parameters, whereas the villi width was increased. The villi height decreased in the infected XID animals; however, it was increased in the XID + B1 I group. Leishmania (L) infantum chagasiinfection caused a decrease in the number of Paneth cells; however, their area was increased. Finally, goblet cells and enterocytes presented different change profiles among groups. This study showed that the parasite infection causes structural and histopathological alterations in the intestine. These changes might be influenced by the absence of B‐1 cells.

Leishmania (Viannia) braziliensis is one of the main causes of cutaneous leishmaniasis in the Americas. This species presents genetic polymorphism that can cause destructive lesions in oral, nasal, and oropharyngeal tracts. In a previous study, the parasite caused several histopathological changes to hamster ileums. Our study evaluates immune response components, morphological changes, and effects on neurons in the ileums of hamsters infected by three different strains of L. (V.) braziliensis in two infection periods. For the experiment, we separated hamsters into four groups: a control group and three infected groups. Infected hamsters were euthanized 90- or 120-days post infection. We used three strains of L. (V.) braziliensis: the reference MHOM/BR/1975/M2903 and two strains isolated from patients who had different responses to Glucantime® treatment (MHOM/BR/2003/2314 and MHOM/BR/2000/1655). After laparotomy, ileums were collected for histological processing, biochemical analysis, and evaluation of neurons in the myenteric and submucosal plexuses of the enteric nervous system (ENS). The results demonstrated the increase of blood leukocytes after the infection. Optical microscopy analysis showed histopathological changes with inflammatory infiltrates, edemas, ganglionitis, and Leishmania amastigotes in the ileums of infected hamsters. We observed changes in the organ histoarchitecture of infected hamsters when compared to control groups, such as thicker muscular and submucosa layers, deeper and wider crypts, and taller and broader villi. The number of intraepithelial lymphocytes and TGF-β-immunoreactive cells increased in all infected groups when compared to the control groups. Mast cells increased with longer infection periods. The infection also caused remodeling of intestinal collagen and morphometry of myenteric and submucosal plexus neurons; but this effect was dependent on infection duration. Our results show that L. (V.) braziliensis infection caused time-dependent alterations in hamster ileums. This was demonstrated by the reduction of inflammatory cells and the increase of tissue regeneration factors at 120 days of infection. The infected groups demonstrated different profiles in organ histoarchitecture, migration of immune cells, and morphometry of ENS neurons. These findings suggest that the small intestine (or at least the ileum) is a target organ for L. (V.) braziliensis infection, as the infection caused changes that were dependent on duration and strain.

Cerca de um quarto da população mundial está infectada por geohelmintos. O objetivo deste trabalho foi investigar a prevalência e os preditores associados às enteroparasitoses em crianças atendidas durante duas décadas. Um estudo retrospectivo foi realizado com crianças (0-18 anos) atendidas no período de 1997 a 2016 por uma instituição pública do Sul do Brasil. A análise dos dados foi realizada utilizando-se o Stata® 9.1. Foram analisados 7.292 registros; a prevalência global foi de 25,5%. A maioria dos registros apresentou infecção por protozoário (69,4%). Os parasitas intestinais mais prevalentes foram Entamoeba coli (9,4%) e Giardia duodenalis (8,9%). Associações estatisticamente significativas (p<0,05) foram encontradas entre parasitas intestinais e variáveis preditoras de sexo e idade. As maiores taxas de infecção foram detectadas em indivíduos de 0 a 4 anos por G. duodenalis (OR 7,2, p<0,001). As menores taxas de infecção foram no grupo 10-14 (OR 1,7, p<0,001). Em todas as faixas etárias, G. duodenalis causou mais infecções e foi mais comum no sexo masculino (OR 1,3; p<0,001).