Morphometric study of the hepatic lesions experimentally induced in hamsters by<i>Entamoeba dispar</i>and<i>E. histolytica</i>

Costa, Camila Adriana Barbosa; Brito, Keyla Novaes Oliveira de; Gomes, Maria Aparecida; Caliari, Marcelo Vidigal

doi:10.1051/parasite/2007144329

Cited by 16 publications

(17 citation statements)

References 11 publications

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“…In accordance, no significant differences in the extension of the necrotic area were observed in livers from hamsters inoculated with E. histolytica or E. dispar ( E. histolytica : 5.2 × 10 5 ± 7.2 × 10 5 ; E. dispar : 3.1 × 10 6 ± 2.7 × 10 6 ; p > 0.05). The data corresponding to the number of trophozoites and extension of the necrotic areas after 24, 48, 72, 144, and 192 h of infection were collected and analyzed previously and they were used in the present study [7]. Neither macro- nor microscopic lesions were observed in animals inoculated with E. histolytica or E. dispar flora.…”

Section: Resultsmentioning

confidence: 99%

“…Interestingly, Costa et al . reported that the number of trophozoites increased in livers of hamsters infected with both strains at 24 h of inoculation, suggesting that the complement and antibodies actions were not able to completely eliminate the trophozoites [7]. As a consequence, this fact could select subpopulations of resistant parasites and contribute to the development of hepatic abscesses.…”

Section: Discussionmentioning

confidence: 99%

“…Two groups of 30 hamsters 60-days old were inoculated via the intrahepatic route with 100,000 trophozoites of E. dispar MCR and E. histolytica EGG strains, respectively. Maintenance, growth and inoculation of trophozoites were made as described in previous work [7]. The E. dispar and E. histolytica strains were identified by zymodeme analysis and PCR [14,15].…”

Section: Methodsmentioning

confidence: 99%

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Entamoeba histolytica and E. dispar trophozoites in the liver of hamsters: in vivo binding of antibodies and complement

et al. 2010

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BackgroundHuman amoebiasis is caused by the parasitic protozoan Entamoeba histolytica that lives in the large intestine of hosts, where can produce asymptomatic colonization until severe invasive infections with blood diarrhea and spreading to other organs. The amoebic abscesses in liver are the most frequent form of amoebiasis outside intestine and still there are doubts about the pathogenic mechanisms involved in their formation. In this study we evaluated the in situ binding of antibodies, C3 and C9 complement components on trophozoites, in livers of hamsters infected with E. histolytica or E. dispar. These parameters were correlated with the extension of the hepatic lesions observed in these animals and with trophozoites survivor.MethodsHamsters were inoculated intra-hepatically with 100,000 trophozoites of E. histolytica or E. dispar strain and necropsied 12, 24, 48, 72, 144 and 192 h after inoculation. Antibodies, C3 and C9 binding to trophozoites were detected by immunohistochemistry. The estimation of the necrosis area and the number of labeled trophozoites was performed using digital morphometry analysis.ResultsIn the liver sections of animals inoculated with the amoebas, the binding of antibodies to E. histolytica trophozoites was significantly lower than to E. dispar trophozoites. Trophozoites of E. dispar were also more frequently vacuolated and high labeled cellular debris observed in the lesions. Positive diffuse reaction to C3 complement component was more intense in livers of animals inoculated with E. histolytica after 24 and 72 h of infection. C3(+) and C9(+) trophozoites were detected in the vascular lumen, granulomas and inside and in the border of necrotic areas of both infected group animals. C3(+) and C9(+) trophozoite debris immunostaining was higher in livers of E. dispar than in livers of E. histolytica. A positive correlation between necrotic areas and number of C9(+) trophozoites was observed in animals inoculated with E. dispar.ConclusionMorphological and immunohistochemical results suggest that antibodies and complement are able to bind and destroy some trophozoites in the liver of experimentally infected hamsters, perhaps selecting the more resistant parasites which are responsible by progression of amoebic abscesses. The findings indicate that E. histolytica possesses an enhanced ability in vivo to evade the immune responses compared to E. dispar, although it also causes experimental hepatic lesions.

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Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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Entamoeba histolytica and E. dispar trophozoites in the liver of hamsters: in vivo binding of antibodies and complement

et al. 2010

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“…Holzer, Sommerville & Wootten (2003) described similar remarks for Sphaerospora truttae stages present within macrophages. The mechanisms related to the progression of the lesion are unknown, but some authors suggested that the destruction of E. histolytica trophozoites could promote the consequent release of toxic products and/or enzymes that would contribute to the increase of necrosis and stimulate the development of the granuloma (Rivero-Nava et al 2002;Costa et al 2007). Costa et al 2010 pointed out the induction of apoptosis by E. histolytica, through direct activation of the host cells distal apoptotic machinery.…”

Section: Parasite Distribution Within the Hostmentioning

confidence: 99%

Development of different diagnostic techniques for Endolimax piscium (archamoebae) and their applicability in Solea senegalensis clinical samples

Constenla

Padrós

Pozo

et al. 2016

Journal of Fish Diseases

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Systemic amoebiasis of sole is caused by Endolimax piscium, a cryptic parasitic archamoeba whose epidemiology and pathogeny are yet unknown. To establish reliable detection methods for this parasite, a battery of molecular diagnostic tools (ISH, PCR and qPCR) were developed and evaluated with a panel of clinical samples from symptomatic diseased fish and from apparently normal animals of different stocks. As there is neither enough background information on the epidemiology of the disease nor a validated reference method, comparison of tests used a composite reference method approach. The ISH technique was the most specific and sensitive in intestine samples and particularly useful as a reference confirmatory method, while the best method in muscle samples was qPCR. Application of the tests to asymptomatic fish demonstrated presence of parasites in a large proportion (>25%) of their intestines, suggesting that this is the point of entry of the amoebae and the initial stage in the development of the disease. The triggering factors that facilitate the breaching of the intestinal barrier by E. piscium, causing granulomatous lesions in other organs and systemic spreading, are not completely understood but our results point to the connective tissue as a preferential target for parasite development and migration.

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“…12 In addition, a gradual decrease was observed in the number of trophozoites in the course of infection. The decrease of trophozoites number associated with progressive increase of necrosis during inflammatory kinetics suggested that trophozoites destruction could promote the consequent release of toxic products that would contribute to the increase of necrosis.…”

Section: Introductionmentioning

confidence: 99%

Histopathological and immunohistochemical study of the hepatic lesions experimentally induced by Entamoeba dispar

Costa¹,

Brito²,

Gomes³

et al. 2010

Eur J Histochem

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The sequence of hepatic necrotic-inflammatory events produced by Entamoeba dispar are originally described in this work. For the first time the experimental lesions produced by E. dispar were described in details, as well as the distribution of the trophozoites detected by the immunohistochemistry. Animals experimentally infected with E. dispar presented necrosis, thrombosis and chronic granulomatous inflammation. Immunoreactive products derived from trofozoites were observed close or associated with trophozoites, epithelioid cells, leucocytes and hepatocytes. Few are the articles on the literature about virulence of E. dispar, which is approximately 9 times more frequent than to Entamoeba histolytica (E. histolytica). Variation in the virulence is therefore expected and signalizing the need of the continuity of studies with E. dispar strains from different places in the world. Taking into account that E. dispar is a closely related species to E. histolytica, these studies could determine new elements involved with E. histolytica pathogenesis, helping us to better understand the disease.

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Morphometric study of the hepatic lesions experimentally induced in hamsters byEntamoeba disparandE. histolytica

Cited by 16 publications

References 11 publications

Entamoeba histolytica and E. dispar trophozoites in the liver of hamsters: in vivo binding of antibodies and complement

Entamoeba histolytica and E. dispar trophozoites in the liver of hamsters: in vivo binding of antibodies and complement

Development of different diagnostic techniques for Endolimax piscium (archamoebae) and their applicability in Solea senegalensis clinical samples

Histopathological and immunohistochemical study of the hepatic lesions experimentally induced by Entamoeba dispar

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