Abstract.
Toxoplasma gondii is a protozoan parasite with a worldwide distribution. In both sheep and humans, if the parasite is encountered during pregnancy, fetal infection and abortion can occur. Therefore, Toxoplasma infection in sheep has a major economic impact upon sheep farming. Clinically, there is a need to distinguish recent (acute) infections from longstanding (chronic) infections. However, current serological techniques, such as detection of anti-T. gondii IgG, cannot discriminate between acute and chronic infections. Increasing immunoglobulin avidity is a good determining factor of how recent an infection is. In this study, we describe the application and validation of a T. gondii IgG avidity ELISA, based on the use of an affinity-purified, native T. gondii P30 antigen. The assay was used to examine sera from eight sheep experimentally infected with T. gondii and found that all seroconverted within 21 days post-infection (p.i.), beginning with avidities that were initially low but that increased over time, with all sheep reaching high IgG avidity within 10 weeks p.i. In addition, sera from clinically healthy but T. gondii-seropositive lambs and ewes and seropositive ewes with a history of abortion were also subjected to a preliminary serological investigation. High IgG avidities were found in 80% of the seropositive lambs, in 90% of the clinically healthy ewes and in 97% of the ewes with abortion problems. These findings indicate that the animals had most likely contacted the parasite a longer time ago.
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References
Abu-Zeid YA (2002) Protein G ELISA for detection of antibodies against Toxoplasma SAG1 in dromedaries. J Egypt Soc Parasitol 32:247–257
Aubert D, Maine GT, Villena I, Hunt JC, Howard L, Sheu M, Brojanac S, Chovan LE, Nowlan SF, Pinon JM (2000) Recombinant antigens to detect Toxoplasma gondii-specific immunoglobulin G and immunoglobulin M in human sera by enzyme immunoassay . J Clin Microbiol 38:1144–1150
Björkman C, Naslund K, Stenlund S, Maley SW, Buxton D, Uggla A (1999) An IgG avidity ELISA to discriminate between recent and chronic Neospora caninum infection. J Vet Diagn Invest 11:41–44
Duncanson P, Terry RS, Smith JE, Hide G (2001) High levels of congenital transmission of Toxoplasma gondii in a commercial sheep flock. Int J Parasitol 31:1699–1703
Gottstein B, Hentrich B, Wyss R, Thür B, Busato A, Stärk KD, Müller N (1998) Molecular and immunodiagnostic investigations on bovine neosporosis in Switzerland. Int J Parasitol 28:679–691
Hill D, Dubey JP (2002) Toxoplasma gondii: transmission, diagnosis and prevention. Clin Microbiol Infect 8:634–640
Jenum PA, Stray-Pedersen B, Gundersen AG (1997) Improved diagnosis of primary Toxoplasma gondii infection in early pregnancy by determination of antitoxoplasma immunoglobulin G avidity. J Clin Microbiol 35:1972–1977
Joynson DHM, Wreghitt TG (2001) Toxoplasma infection in immunosuppressed (HIV-negative) patients. In: Joynson DHM, Wreghitt TG (eds) Toxoplasmosis: a comprehensive clinical guide. Cambridge University Press, Cambridge, pp 178–192
Lekutis C, Ferguson DJ, Grigg ME, Camps M, Boothroyd JC (2001) Surface antigens of Toxoplasma gondii: variations on a theme. Int J Parasitol 31:1285–1292
Sager H, Gloor M, Björkman C, Kritzner S, Gottstein B (2003) Assessment of antibody avidity in aborting cattle by a somatic Neospora caninum-tachyzoite antigen IgG avidity ELISA. Vet Parasitol 112:1–10
Seefeldt SL, Kirkbride CA, Dubey JP (1989) Comparison of enzyme-linked immunosorbent assay, indirect fluorescent antibody test, and direct agglutination test for detecting Toxoplasma gondii antibodies in naturally aborted ovine fetuses. J Vet Diagn Invest 1:124–127
Silva NM, Lourenço EV, Silva DAO, Mineo JR (2002) Optimisation of cut-off titres in Toxoplasma gondii specific ELISA and IFAT in dog sera using immunoreactivity to SAG-1 antigen as a molecular marker of infection. Vet J 163:94–98
Villavedra M, Battistoni JJ, Rossi S, Carol H, Nieto A (2001) Avidity analysis of the human immune response to a chitin binding protein of Toxoplasma gondii. Int J Parasitol 31:1087–1092
Wastling JM, Harkins D, Maley S, Innes E, Panton W, Thomson K, Buxton D (1995) Kinetics of the local and systemic antibody response to primary and secondary infection with S48 Toxoplasma gondii in sheep. J Comp Pathol 112:53–62
Werre SR, Jacobson RH, Bowman DD, Dubey JP, Mohammed HO (2002) Evaluation of kinetics and single-read enzyme-linked immunoassays for detection of Toxoplasma gondii antibodies in sheep. J Vet Diagn Invest 14:225–230
Wyss R, Sager H, Müller N, Inderbitzin F, König M, Audigé L, Gottstein B (2000) The occurrence of Toxoplasma gondii and Neospora caninum as regards meat hygiene. Schweiz Arch Tierheilkd 142:95–108
Acknowledgements.
This work was supported by the Swiss Federal Veterinary Office (grant 1.01.02) and BBW grant C01.0122 within the framework of COST 854 ACTION. We are grateful to Ursula Mäusli for her technical assistance in the laboratory.
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Sager, H., Gloor, M., Tenter, A. et al. Immunodiagnosis of primary Toxoplasma gondii infection in sheep by the use of a P30 IgG avidity ELISA. Parasitol Res 91, 171–174 (2003). https://doi.org/10.1007/s00436-003-0964-9
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DOI: https://doi.org/10.1007/s00436-003-0964-9