The use of MM3 monoclonal antibodies for the early immunodiagnosis of ovine fascioliasis.
This study reports a new capture ELISA (MM3-SERO) for the serodiagnosis of sheep fascioliasis, based on the use of the monoclonal antibody (mAb) MM3. Like our previously reported indirect ELISA method, based on the use of a FPLC-purified fraction (fraction IV) of the Fasciola hepatica excretion/secretion antigens (ESAs), this new test was able to detect animals infected with very small numbers of metacercariae (5-40) and showed no cross-reaction with sera from sheep infected with other parasites, i.e., Moniezia spp., Cysticercus tenuicollis, and Dicrocoelium dendriticum. In contrast with these 2 methods, some sera (mainly those obtained from animals infected with D. dendriticum) showed high reactivities in indirect ELISA with whole F. hepatica ESAs used as control. Interestingly, the MM3-SERO ELISA has a better signal-to-noise ratio than the fraction-IV ELISA, thus allowing detection of seroconversion in infected sheep on average 1 wk earlier (3.2 +/- 0.4 wk postinfection [PI] for MM3-SERO ELISA vs. 4.2 +/- 0.9 wk PI for fraction IV ELISA). Moreover, the antibody response detected with MM3-SERO ELISA was more uniform, with seroconversion always occurring at 4 wk PI in sheep with 1-2 flukes and at 3 wk PI in sheep with more than 2 flukes. The MM3-SERO ELISA was also used to evaluate the kinetics of antibody response against MM3-recognized antigens in sera from sheep experimentally infected with F. hepatica and then treated with triclabendazole. Our results showed that antibody levels dropped by about 25% during the 4-wk observation period following the flukicide treatment, whereas they remained invariably high in all sheep left untreated. We conclude that the MM3-SERO ELISA is a 100% sensitive and 100% specific test for the early serodiagnosis of sheep fascioliasis. Preliminary studies in our laboratory seem to indicate that this method may also be useful for the determination of anti-F. hepatica antibodies in serum and milk of other ruminants. A commercial version of MM3-SERO is currently available from BIO X Diagnostics (La Jemelle, Belgium).
Mezo
Mercedes
M
Centro de Investigaciones Agrarias, Mabegondo, P.O. Box 10, 15080, A Coruña, Spain.
González-Warleta
Marta
M
Ubeira
Florencio M
FM
D000818:Animals; D000871:Anthelmintics / Q000627:therapeutic use; D000909:Antibodies, Helminth / Q000096:biosynthesis / Q000097:blood*; D000911:Antibodies, Monoclonal / Q000276:immunology; D000947:Antigens, Helminth / Q000276:immunology / Q000302:isolation & purification; D001562:Benzimidazoles / Q000627:therapeutic use; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000662:veterinary*; D005210:Fasciola hepatica / Q000276:immunology*; D005211:Fascioliasis / Q000175:diagnosis / Q000188:drug therapy / Q000276:immunology / Q000662:veterinary*; D005243:Feces / Q000469:parasitology; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000097:blood; D007700:Kinetics; D012680:Sensitivity and Specificity; D012756:Sheep; D012757:Sheep Diseases / Q000175:diagnosis* / Q000188:drug therapy / Q000276:immunology / Q000469:parasitology; D013997:Time Factors; D000077682:Triclabendazole
D000871:Anthelmintics; D000909:Antibodies, Helminth; D000911:Antibodies, Monoclonal; D000947:Antigens, Helminth; D001562:Benzimidazoles; D007074:Immunoglobulin G; D000077682:Triclabendazole