Development and initial evaluation of a lateral flow dipstick test for antigen detection of Entamoeba histolytica in stool sample.
Entamoeba histolytica infection remains a public health concern in developing countries. Early diagnosis of amoebiasis can avoid disease complications, thus this study was aimed at developing a test that can rapidly detect the parasite antigens in stool samples. Rabbits were individually immunized with recombinant pyruvate phosphate dikinase (rPPDK) and E. histolytica excretory-secretory antigens to produce polyclonal antibodies. A rapid dipstick test was produced using anti-rPPDK PAb lined on the dipstick as capture reagent and anti-EhESA PAb conjugated to colloidal gold as the detector reagent. Using E. histolytica-spiked in stool sample of a healthy individual, the detection limit of the dipstick test was found to be 1000 cells ml-1. Meanwhile when rPPDK was spiked in the stool sample, the minimum concentration detected by the dipstick test was 0.1 μg ml-1. The performances of the dipstick, commercial Techlab E. histolytica II enzyme-linked immunosorbent assays (ELISA) and real-time PCR were compared using 70 stool samples from patients infected with Entamoeba species (n = 45) and other intestinal pathogens (n = 25). When compared to real-time PCR, the diagnostic sensitivity of the dipstick for detection of E. histolytica was 65.4% (n = 17/26); while the diagnostic specificity when tested with stool samples containing other intestinal pathogens was 92% (23/25). In contrast, Techlab E. histolytica II ELISA detected 19.2% (5/26) of the E. histolytica-positive samples as compared to real-time PCR. The lateral flow dipstick test produced in this study enabled rapid detection of E. histolytica, thus it showed good potential to be further developed into a diagnostic tool for intestinal amoebiasis.
a Institute for Research in Molecular Medicine , Universiti Sains Malaysia , Penang , Malaysia.
Syazwan
S
Saidin
a Institute for Research in Molecular Medicine , Universiti Sains Malaysia , Penang , Malaysia.
Muhammad Hafiznur
MH
Yunus
a Institute for Research in Molecular Medicine , Universiti Sains Malaysia , Penang , Malaysia.
Nurulhasanah
N
Othman
b Faculty of Medicine, Department of Parasitology , University of Malaya , Kuala Lumpur , Malaysia.
Yvonne Ai-Lian
YA
Lim
c Department of Medical Microbiology and Parasitology, School of Medical Sciences , Universiti Sains Malaysia , Kubang Kerian , Malaysia.
Zeehaida
Z
Mohamed
c Department of Medical Microbiology and Parasitology, School of Medical Sciences , Universiti Sains Malaysia , Kubang Kerian , Malaysia.
Nik Zairi
NZ
Zakaria
a Institute for Research in Molecular Medicine , Universiti Sains Malaysia , Penang , Malaysia.
Rahmah
R
Noordin
D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology*; D000953:Antigens, Protozoan / Q000276:immunology*; D004404:Dysentery, Amebic / Q000175:diagnosis* / Q000469:parasitology; D004748:Entamoeba histolytica / Q000201:enzymology / Q000276:immunology* / Q000302:isolation & purification; D004797:Enzyme-Linked Immunosorbent Assay; D005243:Feces / Q000469:parasitology; D005260:Female; D006801:Humans; D057230:Limit of Detection; D011772:Pyruvate, Orthophosphate Dikinase / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D011817:Rabbits; D011934:Reagent Strips; D060888:Real-Time Polymerase Chain Reaction; D011994:Recombinant Proteins; D012680:Sensitivity and Specificity; D012698:Serologic Tests
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D011934:Reagent Strips; D011994:Recombinant Proteins; D011772:Pyruvate, Orthophosphate Dikinase
Entamoeba histolytica; excretory-secretory antigens; lateral flow rapid test; pyruvate phosphate dikinase; stool antigen detection