Comparison of multiplex-PCR and antigen detection for differential diagnosis of Entamoeba histolytica.
Amebiasis is an infection caused by Entamoeba histolytica. However, differentiation between E. histolytica and Entamoeba dispar, which are morphologically identical species, is essential for treatment decision, precaution of the invasive disease and public health. The purpose of the present study was to evaluate a Multiplex -PCR for detection and differentiation of E. histolytica from E. dispar from fresh stool samples in comparison with the coproantigen commercial ELISA. Microscopic examination of stools using the Coprotest method, detection of stool antigen by enzyme-linked immunosorbent assay kit and a home made Multiplex-PCR, were used for the diagnosis of amoebiasis infection. Analysis of the 127 stools samples by microscopy examination demonstrated that only 27 (21%) samples were positive for E. histolytica/E. dispar complex. Among these stool samples, 11 were positive by Multiplex-PCR, with nine presenting the diagnostic fragment characteristic of E. dispar (96 bp) and two presenting diagnostic fragment of E. histolytica (132 bp). Among negative samples detected by microscopic examination, three positive samples for E. dispar and one positive for E. histolytica by Multiplex-PCR was observed. This denotes a low sensibility of microscopic examination when a single stool sample is analyzed. Assay for detection of E. histolytica antigen was concordant with multiplex-PCR in relation to E. histolytica. Statistical analysis comparing the sensibility tests was not done because of the low number of E. histolytica cases. The results demonstrate the importance of the specific techniques use for the differentiation between E. histolytica and E. dispar.
Department of Pathology, Medical School, Fluminense Federal University, Niterói, RJ.
Helena Lúcia Carneiro
HL
Santos
Regina Helena Saramago
RH
Peralta
Heloisa Werneck
HW
de Macedo
Magali Gonçalves Muniz
MG
Barreto
José Mauro
JM
Peralta
D000818:Animals; D000953:Antigens, Protozoan / Q000032:analysis; D016054:DNA, Protozoan / Q000032:analysis* / Q000235:genetics; D003937:Diagnosis, Differential; D004747:Entamoeba / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification; D004748:Entamoeba histolytica / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification; D004749:Entamoebiasis / Q000175:diagnosis* / Q000469:parasitology; D005243:Feces / Q000469:parasitology*; D006801:Humans; D007124:Immunoenzyme Techniques; D016133:Polymerase Chain Reaction / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D000953:Antigens, Protozoan; D016054:DNA, Protozoan