Toxoplasma gondii causes alterationsin tunica mucosa and submucosal plexus of the jejunum and proximal colon of rats

Intestinal inflammatory diseases are characterized by alterations that affect the intestinal mucosal cells, goblet cells, local immune system cells and enteric nervous system cells. The secretion of the intestinal epithelium is coordinated by the action of the submucosal plexus through chemical mediators, produced and released by enterocytes, lymphocytes and goblet cells that interact with neurons and enteric glial cells (EGCs), regulating the intestinal mucosa to amplify the immunobiological response, facilitate the intestinal transit and provide a direct action against infectious agents, among them Toxoplasma gondii, an etiological agent of toxoplasmosis, a worldwide-spread zoonosis. To investigate the effects of the chronic infection caused by T. gondii on the mucosal tunica, tela submucosa and submucosal plexus of the jejunum and proximal colon of rats. 20 Rattus norvegicus were utilized, and distributed into a control group (CG), which received one mL of sterile saline solution orally, and an infected group (IG), orally inoculated with a solution containing 500 oocysts of ME-49 strain of T. gondii in one mL of distilled water. Thirty-six days later, they were submitted to anesthetic procedure and euthanized. Samples of the jejunum and the proximal colon were harvested, fixed and submitted to histological processing to evaluate the submucosal tela and tunica using Hematoxilyn eosin, Periodic Acid Schiff and Alcian Blue staining techniques. Total preparations of the submucosal plexus were also done with Giemsa, histochemistry for NADH-diaphorase enzyme and immunohistochemistry to stain nervous and enteric glial cells, vasoactive intestinal polypeptide and S-100β pan glial proteins, respectively. Organs were harvested to perform bioassays in mice. The experimental protocol was efficient to induce infection in rats of IG in which anti-T. gondiiantibodies were detected in a serum exam and tissue cysts were isolated by bioassay. The following was observed in the jejunum: decrease of 12.3% of the tunica mucosa thickness, increase of 7.9% of the submucosal tela, 7.10% of villus height and 17.37% of crypt depths. The number of stained neurons by Giemsa and NADH-diaphorase decreased 15.38%and 40.71%, whereas the areas of the cell bodies increased 5.57 and 23.60%, respectively. There was a 19% reduction in the number of EGCs in the jejunum submucosal plexus. In the proximal colon, the tunica mucosa thickened 48.14% and the crypts deepened 43.02%. The total population of submucosal neurons stained by Giemsa decreased 16.20%. However, the neurons stained by immunohistochemistry for vasoactive intestinal polypeptide increased 25.95%. Intra-epithelial lymphocytes increased 62.86%. Goblet cells capable of producing sulfomucins were reduced by 22.87%. The chronic infection caused by T. gondii significantly altered the tunica mucosa, submucosal tela and induced the death of neurons in the submucosal plexus of the jejunum and proximal colon of rats.Doenças inflamatórias do intestino são caracterizadas por alterações que afetam as células da mucosa intestinal, as células caliciformes, células do sistema imune local, além de causar danos às células do sistema nervoso entérico.A secreção no epitélio intestinal é coordenada pela ação do plexo submucoso do sistema nervoso entérico, por meio de mediadores químicos produzidos e liberados por enterócitos, linfócitos e células caliciformes, que interagem com neurônios e células da glia entérica regulando a mucosa intestinal no intuito de ampliar a resposta imunobiológica, facilitar o trânsito intestinal e promover uma ação direta contra agentes infecciosos, dentre eles, o Toxoplasma gondii, agente etiológico da toxoplasmose, zoonose de distribuição mundial. Investigar os efeitos da infecção crônica causada pelo T. gondiisobre a túnica mucosa, tela submucosae o plexo submucoso do jejuno e do cólon proximal de ratos. Foram utilizados 20 Rattus norvegicus, distribuídos em grupo controle (GC), que receberam um mL de solução salina estéril por via oral e grupo infectado (GI), inoculados com solução contendo 500 oocistos da cepa ME-49 de T. gondiiem um mL de água destilada pela mesma via. Trinta e seis dias após,foram submetidos ao procedimento anestésico, seguido pela eutanásia. Amostras do jejuno e do cólon proximal foram coletadas, fixadas e submetidas ao processamento histológico para avaliação da túnica mucosa e tela submucosa,coradaspelas técnicas de Hematoxilina eosina, Periodic Acid Schiff e Alcian Blue. Foram elaborados preparados totais do plexo submucoso para evidenciar neurônios e células da glia entérica através das técnicas de Giemsa, histoquímica para enzima NADH-diaforase e imunohistoquímica para evidenciar o polipeptídeo intestinal vasoativo e a proteína pan glial S-100β, respectivamente.Foram coletados órgãos para realização de bioprova em camundongos. O protocolo experimental foi eficaz na indução da infecção nos ratos do GI, nos quais anticorpos anti-T. gondiiforam detectados em exame sorológico e cistos teciduais foram isolados por meio da bioprova. No jejuno observamos:redução de 12,3% da espessura da túnica mucosa;aumento de 7,9% da espessura da tela submucosa; 7,10% na altura dos vilos e 17,37% da profundidade das criptas. O número de neurônios evidenciados pelas técnicas de Giemsa e NADH-diaforase positivos sofreu redução de 15,38 e 40,71%, enquanto as áreas dos corposcelulares aumentaram 5,57 e 23,60%, respectivamente. Houve redução de 19% de células da glia entérica no plexo submucoso do jejuno. No cólon proximal, houve aumento na espessura da túnica mucosa e da profundidade das criptas em 48,14 e 43,02%, respectivamente. A população total de neurônios submucosos evidenciados pela técnica de Giemsa reduziu em 16,20%. Já os neurônios evidenciados pela imunohistoquímica parapolipeptídeo intestinal vasoativo aumentaram em 25,95%. Os linfócitosintra-epiteliais aumentaram 62,86%. As células caliciformes produtoras de sulfomucinas reduziram em 22,87%. A infecção crônica provocada pelo Toxoplasma gondiicausou alterações significativas na túnica mucosa e tela submucosa, provocou a morte de células da glia entérica no plexo submucoso do jejuno e em neurônios submucosos do jejuno e do cólon proximal de ratos.1 CD-ROM (116 f.

Effects of associations of tannins from Anacardium occidentale and Anadenanthera colubrina with cephalosporin against bovine Staphylococcus aureus isolates

ABSTRACT: The association of natural compounds isolated from medicinal plants with conventional antibiotics, both with similar mechanisms of action, have become a viable alternative strategy to overcome the problem of drug resistance. This study aimed to evaluate the in vitro antimicrobial activity of tannic substances present in the bark of Anacardium occidentale and Anadenanthera colubrina against samples of Staphylococcus aureus when in combination with cephalexin. These combinations were evaluated by determining the minimum inhibitory concentration (MIC). For this purpose, tannins and cephalexin were serially dissolved in distilled water at concentrations ranging from 0.976 mg/mL to 500 mg/mL and 2 mg/mL to 512 mg/mL, respectively. When combined, the compounds inhibited S. aureus growth forming halos ranging from 0.9 to 46 mm with an MIC of 7.8 mg/mL (tannins) and 4 µg/mL (cephalexin). The resulting effect of the combination of natural and synthetic substances with similar mechanisms of action presented better results than when tested alone. Thus, the conclusion is that both the tannins and cephalexin had their antimicrobial action enhanced when used in combination, enabling the use of lower concentrations while maintaining their antibacterial effect against strains of S. aureus

Immunocompetent host develops mild intestinal inflammation in acute infection with <i>Toxoplasma gondii</i> - Fig 5

<p>Myeloperoxidase activity in duodenum (A), jejunum (B) and ileum (C) and nitrite dosage as an indirect way to measure nitric oxide in the duodenum (D), jejunum (E) and ileum (F) at different times of early infection with oocysts of <i>T</i>. <i>gondii</i>. Data are mean ± S.E.M., * <i>p</i> < 0.05, compared to the control group (ANOVA, Tukey’s test). CG (Control group), G6, G12, G24 G48 and G72 (rats infected for 6, 12, 24, 48 or 72 hours with oocysts of ME 49 strain of <i>T</i>. <i>gondii</i>, respectively).</p

Representative photomicrographs of rat mesenteric microcirculation.

<p>CG (Control group), G6, G12 and G24 (infected for 6, 12 and 24 hours with oocysts of ME 49 strain of <i>T</i>. <i>gondii</i>). Increased number of rolling leukocytes was observed in the G6 and G12 and number of adherent in G24 in comparison with CG. Leukocytes (arrow). Final magnification: 3400x.</p

Representative photomicrograph and graphs for immunohistochemical evaluation of the expression of ICAM-1, PECAM-1 and P-selectin molecules on the mesenteric vascular endothelium of rats orally infected with <i>T</i>. <i>gondii</i> oocysts (ME49).

<p>Data are mean ± S.E.M. * <i>p</i> < 0.05, compared to the control group (ANOVA, Tukey’s test). CG (Control group), G6, G12, G24 G48 and G72 (rats infected for 6, 12, 24, 48 or 72 hours with oocysts of ME 49 strain of <i>T</i>. <i>gondii</i>, respectively).</p

Real-time quantitative PCR assay in the small intestine of <i>T</i>. <i>gondii</i> infected rats.

<p>Real-time quantitative PCR assay in the small intestine of <i>T</i>. <i>gondii</i> infected rats.</p