Identificación molecular de Entamoeba histolytica, Entamoeba dispar y Entamoeba moshkovskii en niños con diarrea en Maracaibo, Venezuela

Introducción. Las amebas no patógenas Entamoeba dispar, Entamoeba moshkovskii y Entamoeba bangladeshi son morfológicamente idénticas a Entamoeba histolytica, parásito responsable de la amebiasis, por lo cual se necesitan técnicas moleculares para diferenciarlas.Objetivo. Determinar la frecuencia de las diferentes especies de Entamoeba mediante reacción en cadena de la polimerasa (Polymerase Chain Reaction, PCR) en muestras fecales de niños menores de cinco años con diarrea, provenientes de Maracaibo (Venezuela).Materiales y métodos. Se recolectó una muestra fecal por individuo en 75 niños con diarrea (grupo de casos) y en 25 niños sin diarrea (grupo control). Las heces se evaluaron mediante examen microscópico, método de concentración de formól-éter y PCR múltiple anidada en una sola ronda para identificar E. histolytica, E. dispar y E. moshkovskii. Además, se hizo una encuesta en la que se recopilaron los datos demográficos, signos, manifestaciones clínicas y estrato socioeconómico de los niños.Resultados. El 48 % de los participantes (38 del grupo de casos y 10 del grupo de control) tenían enteroparásitos. Solo en las muestras de cuatro de los niños, se encontraron quistes del complejo Entamoeba (tres en el grupo de casos y uno en el de control). Mediante PCR se amplificaron nueve muestras (9 %) para la detección de las amebas estudiadas. En el grupo de casos se registraron tres (28,13 %) de E. histolytica, cuatro (30,50 %) de E. dispar y una (9,37 %) de E. moshkovskii, en tanto que solo una (25 %) muestra amplificó para E. dispar en el grupo de control.Conclusión. En general, predominó E. dispar; sin embargo, todos los infectados con E. histolytica se detectaron en el grupo de niños con diarrea y se detectó el primer caso de E. moshkovskii en la región.

Molecular Identification and Prevalence of Entamoeba histolytica, Entamoeba dispar and Entamoeba moshkovskii in Erbil City, Northern Iraq

The present study was conducted to evaluate the infection rates of Entamoeba histolytica, Entamoeba dispar, and Entamoeba moshkovskii among asymptomatic individuals in Erbil City, northern Iraq. The research intent was to discover whether pathogenic or nonpathogenic species cause a high rate of symptomless Entamoeba infections. Stool samples were microscopically examined, and the 18S-rRNA gene was targeted utilizing the nested PCR technique in the positive specimens. Initial results based on morphological features showed that the Entamoeba prevalence rate was 7.4%. Significantly higher rates of infections were seen in females than in males and in low-income people than in moderate-income people. The incidence rates among the asymptomatic individuals, as determined by molecular analysis, were as follows: E. histolytica – 6%, E. dispar – 4.3%, and E. moshkovskii – 0.3%. Of all the Entamoeba positive samples, a single infection with E. histolytica was identified in 41.4% samples; the single infection with E. dispar in 18.6% samples, 35.7% samples had mixed infections with two Entamoeba species, and 4.3% had mixed infections with three species. The current study concluded that 7.4% of healthy people, who live in the endemic area under investigation, carry Entamoeba species asymptomatically. Additionally, the majority of asymptomatic Entamoeba infections were caused by the pathogenic E. histolytica (81.4%) compared to E. dispar (58.6%), and E. moshkovskii with the lowest rate of infection. Single and co-infections with E. histolytica and E. dispar were noted. E. moshkovskii, which was identified for the first time in the region, was only seen in mixed infections.

First report of Entamoeba moshkovskii in human stool samples from symptomatic and asymptomatic participants in Kenya

Entamoeba moshkovskii is a member of the Entamoeba complex and a colonizer of the human gut. We used nested polymerase chain reaction (PCR) to differentiate Entamoeba species in stool samples that had previously been screened by microscopy. Forty-six samples were tested, 23 of which had previously been identified as Entamoeba complex positive by microscopy. Of the 46 specimens tested, we identified nine (19.5%) as E. moshkovskii-positive. In seven of these nine E. moshkovskii-positive samples, either E. dispar or E. histolytica (or both) were also identified, suggesting that co-infections may be common. E. moshkovskii was also detected in both symptomatic and asymptomatic participants. To the best of our knowledge, this is the first report of E. moshkovskii in Kenya.

Differential detection of Entamoeba species in stool samples collected from children in District Swat, Khyber Pakhtunkhwa Pakistan

BackgroundAmoebiasis is an intestinal disease caused by enteric protozoan called Entamoeba histolytica belongs to the Genus Entamoeba. The main reason of infection is the contamination of food and water due to the poor sanitation. Among Entamoeba species, Entamoeba histolytica is highly pathogenic while the other species are non-pathogenic and needs no medical treatment.MethodologyA total of 400 stool samples were collected from different areas of district Swat and were processed for screening of amoebic cells. Microscopically identified samples containing amoebic cells were stored at −20 °C till DNA extraction. Extracted DNA was used in a PCR reaction with specific reference primers to amplify the target DNA.ResultsOut of all 400 stool samples 111 (27.7%) were found positive through microscopy while PCR reaction confirmed 80 out of microscope positive samples. Among 80 PCR positive samples, the infection with Entamoeba dispar was most common (57.5%) followed by E. histolytica (47.5%) and Entamoeba moshkovskii (20%). The positive cases for mono-infection of E. dispar were 33 (41.25%), followed by E.histolytica 25 (31.25%) and E. moshkovskii 7 (8.75%). The co-infection of E. histolytica with E. dispar and E. moshkovskii was 6 (7.5%) and 2 (2.5%), respectively. Similarly the co-infection of Entamoeba dispar with Entamoeba moshkovskii was also 2 (2.5%) while 5 (6.25%) samples were observed with mixed infection of E. histolytica, E. dispar and E. moshkovskii.Significance of the studyThe aim of the study was to detect and differentiate the E. histolytica, Entamoeba dispar and Entamoeba moshkovskii using conventional microscopy and polymerase chain reaction. The results suggested that the use of PCR is necessary to differentiate E. histolytica from E. dispar and E. moshkovskii and therefore, to avoid unnecessary treatment the present study recommend the use of PCR for the routine diagnosis of amoebiasis in the study area. It is also suggested that further studies from this area may also facilitate the understanding of genetic diversity of these pathogens.