[Comparative observation on the efficacy of several test/probe systems for detecting schistosome circulating antigen].
OBJECTIVE
To compare the efficacy of 5 test/probe systems for the detecting of schistosomal circulation antigen (SCA) in sera from infected rabbits.


METHODS
Nine rabbits were infected with monosexual cercariae (either male or female), 7 rabbits were infected with bisexual cercariae as controls. Blood samples were collected periodically post infection (p.i). 15 rabbits were infected each with 250 bisexual cercaria and divided into 3 groups, 2 groups were treated with allyl thiourea (295-590 mg/kg) from 19 d or 46 d respectively, to inhibit their egg formation. One untreated group was used as control. Blood samples were collected weekly until 8 wk post infection. SCA detecting methods include (1) dot-ELISA/McAb anti-surface membrane antigen of adult worms (8SE4), (2) dot-ELISA/McAb anti-CCA (3D10), (3) Sandwich dot-ELISA/McAb anti-egg antigen (MG2), (4) Sandwich-ELISA/McAb anti-egg antigen (2H10), (5) Sandwich-ELISA/McAb anti-CAA (1B10).


RESULTS
Using method (1) all of the 18 rabbits infected with monosexual cercariae were negative. Using method (2) only 1 rabbit harboured 133 male worms showed positive. Using method (5) no SCA were detected in sera from female cercariae-infected rabbits but 3 out of 9 male cercariae-infected rabbits showed positive reaction. SCA detecting results from rabbits treated with allyl thiourea: both method (1) and (3) showed negative in rabbits treated from 19 d (p.i.) but all gave positive reaction in 6-7 wk in rabbits treated from 46 d (p.i.). There were all negative detected by using method (4) and all positive at 6 wk (p.i.) detected by method (5) in rabbits of 3 groups whether treated or non-treated.


CONCLUSIONS
Various test/probe systems have different efficacy in detecting SCA but (5) of the methods (1)(2) tests/probe systems could not detect SCA in rabbits with single female cercariae infection. From the egg formation inhibition study, the SCA detected by McAb 8SE4 dot-ELISA might be related to egg maturation. Whether the surface membrane antigen of adult worm has common antigenic component with egg antigen remains to be studied.
Qiu
L
L
Institute of Parasitic Diseases, Chinese Academy of Preventive Medicine, Shanghai 200025.
Zhang
Y
Y
Li
H
H
Xue
H
H
Lou
W
W
Xu
D
D
Qian
Z
Z
Lu
P
P
Deelder
A
A
D000818:Animals; D000947:Antigens, Helminth / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D007814:Larva / Q000276:immunology; D008297:Male; D011817:Rabbits; D012549:Schistosoma japonicum / Q000276:immunology*
D000947:Antigens, Helminth