Entamoeba histolytica and Entamoeba dispar: differentiation by Enzyme-Linked Immunosorbet Assay (ELISA) and its clinical correlation in pediatric patients

Studies were carried out at a mexican pediatric hospital to determine the ratio between the pathogenic species Entamoeba histolytica and non-pathogenic species E. dispar using an enzyme-linked immunosorbent assay (ELISA) to detect the lectin (1 galactose N-acetyl D-galactosamine) of E. histolytica in feces. A close correlation was noted between the presence of the E. histolytica lectin and clinical symptoms. In the study, amebas were detected by microscopy in 120 children (either E. histolytica or E. dispar). But while almost all (13/14) of the children with E. histolytica had clinical symptoms, dysentery-feces with mocus and blood, diarrhea, cramping abdominal pain, tenesmus rectal, flatulence, vomiting and headache, almost none (1/106) of the children infected with the non-pathogenic ameba E. dispar had signs and symptoms. This suggests that much of the amebiasis diagnoses made in Mexico are, in fact, due to non-pathogenic E. dispar.

Intestinal amoebiasis: delayed-type hypersensitivity response in mice.

Delayed-type hypersensitive (DTH) response was evaluated in C3H/HeJ mice intestinally infected with Entamoeba histolytica. Infected and non-infected control mice were challenged with amoebic antigen on day 5, 10, 15, 20, 25, 30, 40, 50, and 60 post-infection. Maximum footpad swelling was observed after 24 hours of the challenge. The E. histolytica-infected mice exhibited a DTH response on day 5, 15, 20, 25, 40 and 60 post-infection. However, on day 10, 30, and 50, such response was similar to that of the non-infected control mice. The mice developed an evident DTH response late in the course of infection (25 days post-infection). The infected mice did not show any alteration to their DTH response against heterologous unrelated antigen (sheep red blood cells), suggesting that cellular anergy was antigen-specific.

Ausência de amebíase invasiva em aidéticos homossexuais masculinos, no Recife / Absence of invasive amoebiasis in male homosexual AIDS patients in Recife

The purpose of this paper was to determine if among male homosexual AIDS [correction of SIDA] patients, the Entamoeba histolytica was able to product invasive illness. From the 77 investigated patients only one (1.3 per cent) has cysts of E. histolytica in his stools. The electrophoresis of the only isolated strain has shown it was from zimodeme I, non pathogenic. The research of antiamebic antibodies was negative in the serum of the totality of patients. Those results showed that even in immunocompromised patients with AIDS [correction of SIDA], E. histolytica strain found in Recife was not able to produce disease. The utilization of metronidazol is not indicated in amoebic cysts carriers.

Amibiasis, aspectos de interés para el internista / Amebiasis. interesting aspects for the internist

La amibiasis es una enfermedad parasitaria común, de distribución mundial, que tiene gran impacto en la salud. Entamoeba histolytica es el protozario causante de este padecimiento. Puede vivir en forma comensal en el intestino humano, pero en ocasiones invade la mucosa intestinal y otros tejidos, principalmente hígado y pulmón. La infección depende de factores provenientes del parásito y del huésped y se encuentra estrechamente relacionada con el nivel socioeconómico de las comunidades. A pesar de que la amibiasis responde al tratamiento, en ocasiones puede ser letal; es por ello muy importante contar con un diagnóstico oportuno y un tratamiento eficaz. Para lograrlo se han estudiado ampliamente los diferentes aspectos de esta enfermedad, así como la biología de Entamoeba histolytica. El objetivo de esta revisión es proporcionar un panorama generalizado y actualizado sobre los aspectos de esta parasitosis

Seroepidemiología de la amebiasis / Seroepidemiological study of amebiasis

Por medio de la técnica de ELISA se estudiaron 35 sueros de personas del distrito de Sapillica (Piura) y 36 sueros de estudiantes de la Joya (Arequipa) encontrándose que el 46 por ciento de los sueros de Sapillica y el 72 por ciento de los sueros de La Joya eran positivos para anticuerpos contra Entamoeba histolytica.

Autoimmunity in amoebiasis.

Amoebic liver abscess (ALA) and symptomatic intestinal amoebiasis cases were assessed by indirect haemagglutination assay for auto-reactive IgG and IgA class of antibodies in response to healthy human serum IgG and IgA. The present results indicated the presence of autoreactive IgG and IgA class of antibodies in ALA and intestinal amoebiasis respectively.

Anti-amoebic antibody levels in gastro-intestinal disorders.

Serum anti-amoebic antibody levels were studied in 91 cases having clinical presentation of bowel disorders and 31 cases of control. Anti-amoebic antibody was positive in significant dilutions in 38 cases (31.15%) in total comprising 9 cases out of 22 cases showing presence of Ent histolytica cyst in stool, 13 cases who were positive for ova, parasite and cysts other than Ent histolytica in stool and 16 cases out of 70 cases with negative stool findings. It was positive in 5 cases out of 9 diagnosed cases of amoebic liver abscess. Assessment of immunoglobulin levels in amoebic liver abscess cases revealed high levels of immunoglobulin G and immunoglobulin M.

Antibodies against Entamoeba histolytica in individuals with intestinal amoebiasis presenting cysts and/or trophozoites in the feces

Amostras de soros foram obtidas de 154 individuos comprovadamente parasitados pela Entamoeba histolytica (78 sintomaticos e 76 assintomaticos). Doze apresentavam trofozoitas nas fezes, enquanto 142 tinham apenas cistos. Os soros foram utilizados para testar a ocorrencia de anticorpos anti-Entamoeba histolytica, empregando-se para tal, Reacao de Hemaglutinacao Indireta (HAI), Reacao de Imunofluorescencia Indireta (RIFI), Reacao de Fixacao de Complemento (RFC) e Contraimunoeletroforese (CIEP). Entre os soros dos individuos com trofozoitas em suas fezes, 75,0 por cento foram positivos para HAI e RIFI, 83,3 por cento por RFC, e 41,7 por cento por CIEP. Nos individuos que tinham apenas cistos, resultados positivos pelos mesmos testes foram respectivamente, 5,6 por cento; 12,0 por cento; 19,0 por cento e 5,6 por cento. A diferenca em relacao aos titulos de anticorpos detectados atraves de HAI, RIFI, RFC e CIEP e em relacao a presenca de trofozoitas ou cistos nas fezes foi significativa para as quatro reacoes imunologicas, quando 'X IND. 2' foi empregado (P<0,05).

Development of simple and stable ELISA for detection of copro antigen in intestinal amoebiasis.

A simple, sensitive and stable ELISA (enzyme linked immunosorbent assay) was developed using rabbit antibody to fractionated Entamoeba histolytica antigen for the detection of copro antigen in the faeces of individuals with intestinal amoebiasis. In this test none of the healthy individuals, all trophozoite positive, 40% cyst passers and 6% individuals living in endemic area showed the presence of copro antigen. ELISA using polyclonal rabbit antibody could detect 1-5 trophozoites/well and 20-50 ng protein per well of NIH-200 strain of E. histolytica and the sensitivity of the test was comparable with that using monoclonal antibody. Cross reaction was observed only with E. invadens when faeces having other parasites were screened. The reagents of ELISA were stabilized and found to be stable for more than 6 months when stored at 4 degrees C.