Application of the Polymerase Chain Reaction to the Epidemiology of Pathogenic and Nonpathogenic Entamoeba histolytica

Acuña-Soto, Rodolfo; Samuelson, John; Girolami, P De; Zárate, Lina; Millan-Velasco, F.; Schoolnick, G; Wirth, D

doi:10.4269/ajtmh.1993.48.58

Cited by 111 publications

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“…[41][42][43] Infection with E. histolytica/E. dispar in endemic areas frequently coexists with other protozoa and helminths 35 ; therefore, to avoid the interpretation biases observed in previous investigations 41 we included in the study only those cases infected with E. histolytica/E. dispar.…”

Section: Discussionmentioning

confidence: 99%

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Differentiation of entamoeba histolytica/entamoeba dispar by PCR and their correlation with humoral and cellular immunity in individuals with clinical variants of amoebiasis.

Sánchez-Guillén¹,

Pérez-Fuentes

Salgado-Rosas

et al. 2002

The American Journal of Tropical Medicine and Hygiene

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Abstract. To correlate a particular state of immunity with Entamoeba spp., we used colorimetric PCR to differentiate E. histolytica from E. dispar in individuals with amoebiasis and to associate its presence with the clinical profile, including humoral and cellular immune responses to E. histolytica. Our results showed high levels of antibody in acute amoebiasis and elevation of IL-4 production, a cytokine related to Th2 profile, associated with E. histolytica. In chronic amoebiasis, even with anti-E. histolytica seropositivity, intestinal symptoms were associated with E. dispar in all the cases, without differences in level of antibodies, BTI, CD4+/CD8+ ratio, INF-␥, and IL-4. Among asymptomatic carriers, E. dispar was more frequently found; however, identification of E. histolytica in two asymptomatic carriers associated with high levels of INF-␥, a cytokine related to Th1 profile, demonstrate the importance of making specific diagnosis of Entamoeba spp., to establish the clinical and epidemiological behavior in both intestinal and extra-intestinal amoebiasis.

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Section: Discussionmentioning

confidence: 99%

“…10 The existence of asymptomatic carriers of E. histolytica, [34][35][36][37][38] has raised doubts about the proportion of individuals infected who are truly at risk of invasive amoebiasis, and questions the human host factors, that favors this apparently commensal-like relationship with E. histolytica.…”

Section: Discussionmentioning

confidence: 99%

Differentiation of entamoeba histolytica/entamoeba dispar by PCR and their correlation with humoral and cellular immunity in individuals with clinical variants of amoebiasis.

Sánchez-Guillén¹,

Pérez-Fuentes

Salgado-Rosas

et al. 2002

The American Journal of Tropical Medicine and Hygiene

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“…Acuña-Soto et al (1993) aplicaron PCR en muestras de materia fecal para diferenciar E. histolytica patógena de no patógena en una población rural de México 38 . En 1997 se utilizó este método para diferenciar los quistes de E. histolytica y E. dispar 3,39 .…”

Section: This Article Presents a History Of Entamoeba Histolytica Spaunclassified

Historia del protozoo Entamoeba histolytica

2008

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“…21 However, E. histolytica has been reported in other areas such as Bangladesh 13 and Mexico as the predominant species and a large number of mixed infections have been reported. 22 Today, it is accepted that in areas where invasive amoebiasis is common, E. dispar is also a prevalent species. 23 We believe that E. dispar is the predominant species in the central regions of Iran.…”

Section: Distribution and Differential Diagnosis Of Entamoeba Histolymentioning

confidence: 99%

Distribution and Differential Diagnosis ofEntamoeba HistolyticafromEntamoeba Disparby the PCR-RFLP Method in Central Iran

2003

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Background: Entamoeba histolytica and Entamoeba dispar are two morphologically indistinguishable human protozoan parasites that are genetically distinct species. The potential invasive pathogenic Entamoeba histolytica and non-invasive parasite Entamoeba dispar can be differentiated by molecular and other methods. We used polymerase chain reaction (PCR) to determine the ratio of the two species in a population in Tehran and Karaj in central Iran. Materials and Methods:Human stool samples (n=12 148) were randomly collected in Tehran and Karaj and examined for E. histolytica/E. dispar cysts with direct and formalin-ether methods. Eighty-seven (0.7%) cases were positive, of which 49 (62.8%) isolates were successfully cultured in Robinson's medium. A pair of oligonucleotide primers designed from sequence data for genomic DNA coding the 30-KD surface antigen of E. histolytica/E. dispar was used to amplify a 374 base-pair (bp) fragment. The electrophoretic pattern of the PCR product digested with Hinfl restriction enzyme was used for differentiation of the two species. Results: The restriction fragment length polymorphism (RFLP) pattern obtained from a standard E. histolytica isolate had two fragments (219 bp and 155 bp), but the standard isolate of E. dispar showed three fragments (155,152 and 67 bp Entamoeba histolytica is a cosmopolitan human protozoan parasite responsible for amoebic colitis and extraintestinal amoebiasis. Although 90% of infected individuals are asymptomatic, WHO estimates that every year more than 40 to 50 million cases of invasive amoebiasis occur in the world, resulting in up to 100 000 deaths. 1,2After malaria, amoebiasis is the second most fatal human protozoan parasitic diseases in the world. Many people infected with E. histolytica are asymptomatic and never develop clinical symptoms.3 What was earlier known as E. histolytica actually comprises two genetically distinct but morphologically identical species, one potentially pathogenic and the other non-pathogenic. 4 On the basis of biochemical, immunological and genetic data, a formal re-description of E. histolytica was published in 1993, separating E. histolytica (potential pathogenic) from the harmless commensal, E. dispar.5 Diagnosis and differentiation of the two species is important in therapy and also from an epidemiological point of view. Analysis of restriction fragment length polymorphism (RFLP) and direct sequencing of various genes amplified by polymerase chain reaction (PCR) has revealed 2.2% to 17% differences in the nucleotide sequences of E. histolytica and E. dispar. 6 These findings show that PCR and restriction enzyme digestion could be used as a powerful tool for distinguishing E. histolytica from E. dispar.In Iran, there are no accurate data on E. dispar. This study was carried out to determine the ratio of E. histolytica and E. dispar in a population in Tehran and Karaj in central Iran. Distribution and Differential Diagnosis of Entamoeba Histolytica from Entamoeba Dispar by the PCR-RFLP Method in Central Iran Annals of...

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Application of the Polymerase Chain Reaction to the Epidemiology of Pathogenic and Nonpathogenic Entamoeba histolytica

Cited by 111 publications

References 0 publications

Differentiation of entamoeba histolytica/entamoeba dispar by PCR and their correlation with humoral and cellular immunity in individuals with clinical variants of amoebiasis.

Differentiation of entamoeba histolytica/entamoeba dispar by PCR and their correlation with humoral and cellular immunity in individuals with clinical variants of amoebiasis.

Historia del protozoo Entamoeba histolytica

Distribution and Differential Diagnosis ofEntamoeba HistolyticafromEntamoeba Disparby the PCR-RFLP Method in Central Iran

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