Enzyme-linked immunosorbent assay based on monoclonal and polyclonal antibodies for the detection of Entamoeba histolytica antigens in faecal specimens.
A murine monoclonal antibody (MAb) (Eh208C2-2) raised against crude lysate of the pathogenic HM-1:IMSS strain of Entamoeba histolytica was used in an enzyme-linked immunosorbent assay for the detection of E. histolytica antigens in faecal specimens. The detection limit of the assay was 110 and 280 amoebae/ml of the HM-1:IMSS and HK-9 strains in phosphate-buffered saline, respectively. The assay was applied to single stool samples from 3 groups of individuals comprising 40 patients whose stools were positive for E. histolytica trophozoites and/or cysts (group I), 48 patients whose stools were negative for E. histolytica but positive for other parasites (group II), and 36 parasitologically-negative healthy controls (group III). Positivity rates of 77.5%, 2.1% and 2.7% were found in samples from groups I, II and III respectively. Specificity, positive and negative predictive values, and efficiency of the assay were 97.6%, 93.9%, 90.1% and 91.1% respectively. When group I samples were further divided into a trophozoite-positive subgroup IA (13 samples) and a cyst-positive subgroup IB (27 samples), the positive rates were 100% and 66.7%, respectively (P < 0.025).
Wonsit
R
R
Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
Thammapalerd
N
N
Tharavanij
S
S
Radomyos
P
P
Bunnag
D
D
D000818:Animals; D000913:Antibodies, Protozoan / Q000032:analysis; D000953:Antigens, Protozoan / Q000032:analysis*; D004748:Entamoeba histolytica / Q000276:immunology* / Q000302:isolation & purification; D004749:Entamoebiasis / Q000175:diagnosis; D004797:Enzyme-Linked Immunosorbent Assay; D005243:Feces / Q000469:parasitology*; D006801:Humans
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan