Colite necrohemorrágica causada por Entamoeba histolytica em um cão

Background: Intestinal amebiasis with morphological lesions and clinical manifestations is uncommon in dogs. The disease is caused by the protozoan Entamoeba histolytica, which is commonly observed in its natural hosts, humans and some non-human primates. It is occasionally found in the company of animals, usually associated with contact with infected humans. Thus, the objective here is to describe a case of necro-hemorrhagic colitis caused by E. histolytica in a dog infected with the canine distemper virus, in order to characterize the epidemiological and clinicopathological aspects of the disease.Case: An adult, mixed-breed bitch displaying anorexia and ataxia was referred to the veterinary hospital for treatment. Clinical evaluation showed a cachectic animal with 12% dehydration, ocular discharge, and bilateral purulent nasal dis-charge. A clinical diagnosis of distemper was made, and treatment was instituted. The dog’s signs progressed to walking in circles, aimlessly, with lethargy and blindness. After three days of the onset of neurological signs, the dog developed diarrhea with hematochezia. With no improvement noted, we elected to euthanize the dog. At necropsy, edema was present in subcutaneous tissues, and the lungs had yellow areas in the cranio-ventral portions, which the court was flowing purulent discharge. In the large intestine, segmental distention of the distal portion of the descending colon was observed. The segment was approximately 15 cm in length and consisted of irregular reddish areas. There was also slight thickening of the wall with edematous mucosa containing blood clots, fibrin, and multiple areas of ulceration. Microscopically showed necro-hemorrhagic colitis associated with rounded structures, approximately 15 μm in size, containing abundant eosinophilic cytoplasm that was slightly granular or vacuolated. They also contained nuclei and nucleoli that were central or slightly eccentric. These organisms were consistent with amoeba trophozoites. There was also demyelinating encephalitis associated with malacia, corpuscular intranuclear eosinophilic inclusions and / or intracytoplasmic inclusions in ependymal cells, astrocytes, and gemistocytes, characteristic of infection with canine distemper virus. Using immunohistochemistry with polyclonal anti-E. histolytica antibodies in the dilution of 1:1000, trophozoites were immunomarked, confirming the suspected amebiasis.Discussion: The diagnosis of intestinal amebiasis was based on clinical signs and by morphological characteristics on gross and microscopic examination, and was confirmed as E. histolytica by immunohistochemistry. Limited information on theepidemiology and pathological findings of infection with Entamoeba sp. has been reported in the literature, as it is relatively uncommon in pets. Affected animals are usually asymptomatic, but immunosuppression caused by canine distemper virus may have triggered the clinical manifestations of the disease in this dog. Enteritis due Entamoeba sp. should be considered in dogs with chronic weight loss and bloody diarrhea. It should also be included in the differential diagnoses for weight loss and hemorrhagic gastroenteritis, such as canine parvovirus, canine adenovirus 1, Pythium insidiosum, and Giardia sp

Influence of inflammation on parasitism and area of experimental amoebic liver abscess: an immunohistochemical and morphometric study

The influence of inflammation on the number of trophozoites and on the murine amoebic liver abscess area following infection with Entamoeba histolytica and E. dispar was evaluated. Immunohistochemistry and digital morphometry were used to identify and quantify the trophozoites, neutrophils, macrophages, and lesions. Positive correlation was observed between the number of trophozoites and inflammatory cells. A significant decrease in parasitism and inflammation in groups treated with dexamethasone was observed. The scarceness or absence of trophozoites in the treated groups suggest the importance of the inflammatory response in the production of amoebic hepatic abscesses in spite of the inherent virulence of the parasite being decisive in the establishment of the lesion

IgG Induced by Vaccination With Ascaris suum Extracts Is Protective Against Infection

Human ascariasis has a global and cosmopolitan distribution, and has been characterized as the most prevalent neglected tropical disease worldwide. The development of a preventive vaccine is highly desirable to complement current measures required for this parasitic infection control and to reduce chronic childhood morbidities. In the present study, we describe the mechanism of protection elicited by a preventive vaccine against ascariasis. Vaccine efficacy was evaluated after immunization with three different Ascaris suum antigen extracts formulated with monophosphoryl lipid A (MPLA) as an adjuvant: crude extract of adult worm (ExAD); crude extract of adult worm cuticle (CUT); and crude extract of infective larvae (L3) (ExL3). Immunogenicity elicited by immunization was assessed by measuring antibody responses, cytokine production, and influx of tissue inflammatory cells. Vaccine efficacy was evaluated by measuring the reductions in the numbers of larvae in the lungs of immunized BALB/c mice that were challenged with A. suum eggs. Moreover, lung physiology and functionality were tested by spirometry to determine clinical efficacy. Finally, the role of host antibody mediated protection was determined by passive transfer of serum from immunized mice. Significant reductions in the total number of migrating larvae were observed in mice immunized with ExL3 61% (p < 0.001), CUT 59% (p < 0.001), and ExAD 51% (p < 0.01) antigens in comparison with non-immunized mice. For the Ascaris antigen-specific IgG antibody levels, a significant and progressive increase was observed with each round of immunization, in association with a marked increase of IgG1 and IgG3 subclasses. Moreover, a significant increase in concentration of IL-5 and IL-10 (pre-challenge) in the blood and IL-10 in the lung tissue (post-challenge) was induced by CUT immunization. Finally, ExL3 and CUT-immunized mice showed a marked improvement in lung pathology and tissue fibrosis as well as reduced pulmonary dysfunction induced by Ascaris challenge, when compared to non-immunized mice. Moreover, the passive transfer of specific IgG antibodies from ExL3, CUT, and ExAD elicited a protective response in naïve mice, with significant reductions in parasite burdens in lungs of 65, 64, and 64%, respectively. Taken together, these studies indicated that IgG antibodies contribute to protective immunity

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Influência da Salmonella Enterica Sorovar Typhimurium sobre a virulência da Entamoeba Dispar e da Entamoeba Histolytica in vitro e na colite amebiana experimental

Exportado OPUSMade available in DSpace on 2019-08-10T00:45:21Z (GMT). No. of bitstreams: 1 tese_vers_o_p_s_gradua__o_pdf.pdf: 7378750 bytes, checksum: 1a074a468ad54424204e6be59fff6bdf (MD5) Previous issue date: 13A amebíase é a protozoose mais grave que atinge o ser humano e a segunda maior causa de morte entre as doenças parasitárias, superada apenas pela malária. Considera-se que apenas a Entamoeba histolytica é capaz de penetrar nos tecidos e produzir amebíase invasiva. Contudo, alguns estudos têm demonstrado que a Entamoeba dispar é capaz de produzir lesões em modelos experimentais. Com o objetivo de determinar se as bactérias enteropatogênicas contribuem para aumentar a expressão gênica dos fatores de virulência amebianos, bem como de induzir lesões mais intensas, propusemos avaliar a influência da bactéria Salmonella enterica sorovar Typhimurium sobre a virulência da Entamoeba dispar e da Entamoeba histolytica em trofozoítos isolados da cultura in vitro e avaliar patologicamente a colite amebiana, em ratos infectados com trofozoítos amebianos e co-infectados com S. Typhimurium. As cepas MCR, ADO e VEJ de E. dispar e, EGGp e EGGa de E. histolytica foram cultivadas separadamente e, associadas ou não à bactéria S. Typhimurium. Em seguida foi realizada a extração do RNA dessas culturas para produção de cDNA dos fatores de virulência de E. histolytica e E.dispar e quantificada a expressão dos fatores de virulência. Para a indução de colite amebiana, 8 ratos wistar (Rattus norvegicus) por grupo, previamente submetidos a uma intubação intragástrica da S. Typhimurium, foram inoculados pela via intracecal com 5x105 trofozoítos. Como grupos controles, 40 ratos foram somente inoculados com trofozoítos amebianos das cepas de Entamoeba estudadas. Outros 16 ratos constituíram os grupos controles somente infectados com S. Typhimurium e controle não infectado. Todos os ratos foram sacrificados 7 dias após a infecção amebiana para a coleta do ceco, confecção de lâminas histológicas para análise histopatológica e morfométrica e, para a realização de reações imuno-histoquímicas anti IL-1á, IL4, COX-2 e MUC-2. Nosso estudo permitiu observar que a co-cultura de E. dispar com a enterobactéria S. Typhimurium foi capaz de aumentar a expressão dos fatores de virulência amebianos amebaporo A, cisteína proteinase-5 e lectina ligante de Galactose e N-Acetilgalactosamina. Ao contrário do observado por outros autores, as cepas de E. dispar por nós estudados foram capazes de expressar o fator de virulência amebiano cisteína proteinase-5. A co-cultura de E. histolytica com a enterobactéria S. Typhimurium foi capaz de aumentar a expressão do fator de virulência amebiano amebaporo A. Também verificamos que na maioria dos grupos analisados, a associação in vivo da E. dispar ou da E. histolytica com a S. Typhimurium foi capaz de aumentar a intensidade da colite amebiana ulcerativa, também acompanhada pelo aumento da expressão de mediadores pró-inflamatórios e da redução da expressão de IL-4. Além disso, na maioria dos grupos analisados, a associação in vivo da E. dispar ou da E. histolytica com a S. Typhimurium foi capaz de aumentar a expressão da mucina MUC2, em virtude da maior intensidade da agressão à mucosa colônica. Diante dos resultados obtidos, concluímos que a interação da S. Typhimurium com a E. dispar e a E. histolytica foi capaz aumentar a virulência destas espécies de amebas levando à colite ulcerativa amebiana de maior intensidade.Amebiasis is the most serious protozoa that hits the human intestine and is the second-leading cause of death among parasitic diseases, surpassed only by malaria. It is considered that only Entamoeba histolytica is able to penetrate tissues and produce invasive amebiasis. However, some studies have shown that Entamoeba dispar is capable of producing lesions in experimental models. In order to determine if the enteropathogenic bacteria contribute to increase the gene expression of amebic virulence factors, as well as to induce more intense lesions, we propose to evaluate the influence of Salmonella Enterica sorovar Typhimurium on the virulence of Entamoeba dispar and Entamoeba histolytica in trophozoites isolated from the in vitro culture and pathologically evaluate amoebic colitis in rats infected with amoebic trophozoites and co-infected with S. typhimurium. E. dispar, MCR, ADO and VEJ strains from E. dispar and, EGGp and EGGa from E. histolytica were cultured separately and associated or not with the S. Typhimurium bacterium. Then, the RNA extraction from these cultures was carried out to produce cDNA from the virulence factors of E. histolytica and E.dispar and quantified the expression of the virulence factors. For the induction of amoebic colitis, 8 wistar rats (Rattus norvegicus) per group, previously submitted to an intragastric intubation of S. Typhimurium, were inoculated by the intracecal route with 5x105 trophozoites. As control groups, 40 rats were only inoculated with amebian trophozoites from the Entamoeba strains studied. Another 16 rats were the control groups infected only with S. typhimurium and uninfected control. All rats were sacrificed 7 days after amebic infection to collect cecum, histological slides for histopathological and morphometric analysis, and for the immunohistochemical anti-IL1á, IL4, COX-2 and MUC-2 immunohistochemical reactions . Our study showed that the co-culture of E. dispar with the S. typhimurium enterobacterium was able to increase the expression of amebaporo A, cysteine proteinase-5 and Galactose-binding lectin and N-acetylgalactosamine virulence factors. Contrary to what was observed by other authors, E. dispar strains studied by us were able to express the amoebic virulence factor cysteine proteinase-5. The co-culture of E. histolytica with the S. typhimurium enterobacterium was able to increase the expression of the amebian virulence factor amebaporo A. We also found that in the majority of the groups analyzed, the in vivo association of E. dispar or E. histolytica with S. typhimurium was able to increase the intensity of ulcerative amebic colitis, also accompanied by increased expression of proinflammatory mediators and reduced IL-4 expression. In addition, in most of the analyzed groups, the in vivo association of E. dispar or E. histolytica with S. typhimurium was able to increase MUC-2 mucin expression, due to the greater intensity of aggression to the colonic mucosa. In view of the results obtained, we conclude that the interaction of S. Typhimurium with E. dispar and E. histolytica was able to increase the virulence of these species of amoebae leading to ulcerative amebic colitis of greater intensity

<strong>The long-lasting </strong><em><strong>Ascaris suum</strong></em><strong> antigens in the lungs shapes the tissue adaptation modifying the pulmonary architecture and immune response after infection</strong> <strong>in mice</strong> (<strong>MATERIALS AND METHODS)</strong>

This shared document refers to the additional information on "material and methods" contained in the paper titled (The long-lasting Ascaris suum antigens in the lungs shapes the tissue adaptation modifying the pulmonary architecture and immune response after infection in mice).</p

Colite necrohemorrágica causada por Entamoeba histolytica em um cão

Background: Intestinal amebiasis with morphological lesions and clinical manifestations is uncommon in dogs. The disease is caused by the protozoan Entamoeba histolytica, which is commonly observed in its natural hosts, humans and some non-human primates. It is occasionally found in the company of animals, usually associated with contact with infected humans. Thus, the objective here is to describe a case of necro-hemorrhagic colitis caused by E. histolytica in a dog infected with the canine distemper virus, in order to characterize the epidemiological and clinicopathological aspects of the disease.Case: An adult, mixed-breed bitch displaying anorexia and ataxia was referred to the veterinary hospital for treatment. Clinical evaluation showed a cachectic animal with 12% dehydration, ocular discharge, and bilateral purulent nasal dis-charge. A clinical diagnosis of distemper was made, and treatment was instituted. The dog’s signs progressed to walking in circles, aimlessly, with lethargy and blindness. After three days of the onset of neurological signs, the dog developed diarrhea with hematochezia. With no improvement noted, we elected to euthanize the dog. At necropsy, edema was present in subcutaneous tissues, and the lungs had yellow areas in the cranio-ventral portions, which the court was flowing purulent discharge. In the large intestine, segmental distention of the distal portion of the descending colon was observed. The segment was approximately 15 cm in length and consisted of irregular reddish areas. There was also slight thickening of the wall with edematous mucosa containing blood clots, fibrin, and multiple areas of ulceration. Microscopically showed necro-hemorrhagic colitis associated with rounded structures, approximately 15 μm in size, containing abundant eosinophilic cytoplasm that was slightly granular or vacuolated. They also contained nuclei and nucleoli that were central or slightly eccentric. These organisms were consistent with amoeba trophozoites. There was also demyelinating encephalitis associated with malacia, corpuscular intranuclear eosinophilic inclusions and / or intracytoplasmic inclusions in ependymal cells, astrocytes, and gemistocytes, characteristic of infection with canine distemper virus. Using immunohistochemistry with polyclonal anti-E. histolytica antibodies in the dilution of 1:1000, trophozoites were immunomarked, confirming the suspected amebiasis.Discussion: The diagnosis of intestinal amebiasis was based on clinical signs and by morphological characteristics on gross and microscopic examination, and was confirmed as E. histolytica by immunohistochemistry. Limited information on theepidemiology and pathological findings of infection with Entamoeba sp. has been reported in the literature, as it is relatively uncommon in pets. Affected animals are usually asymptomatic, but immunosuppression caused by canine distemper virus may have triggered the clinical manifestations of the disease in this dog. Enteritis due Entamoeba sp. should be considered in dogs with chronic weight loss and bloody diarrhea. It should also be included in the differential diagnoses for weight loss and hemorrhagic gastroenteritis, such as canine parvovirus, canine adenovirus 1, Pythium insidiosum, and Giardia sp