Evaluation of a commercial ELISA kit for detection of antibodies against Toxoplasma gondii in serum, plasma and meat juice from experimentally and naturally infected sheep

Particle and Fibre Toxicology

Walter Basso²  Peter Deplazes²  Felix Grimm²  Renate Edelhofer¹  Sabine B Glor² 

[1] Department of Pathobiology, Institute of Parasitology and Zoology, University of Veterinary Medicine, Veterinärplatz 1, Vienna, 1210, Austria;Institute of Parasitology, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 266a, Zurich, CH-8057, Switzerland

关键词: Meat juice;    Antibodies;    Indirect haemagglutination;    IFAT;    ELISA;    Diagnosis;    Sheep;    Toxoplasma gondii;   

Others  :  1228017
DOI  :  10.1186/1756-3305-6-85

 received in 2013-02-12, accepted in 2013-03-28,  发布年份 2013

【 摘 要 】

Background

Toxoplasmosis is one of the most common food borne zoonoses worldwide, and can be a serious life-threatening disease in the congenitally infected fetus and in immunosupressed patients. Among food animals, sheep along with goats and pigs possess the highest incidence of T. gondii cysts in meat, and play a major role as a source of human infection.

Methods

In this study, a new commercial ELISA kit (PrioCHECK® Toxoplasma Ab SR, Prionics Schlieren-Zurich, Switzerland) for the detection of anti-T. gondii antibodies in serum, plasma and meat juice of sheep, was evaluated by comparing it with the indirect fluorescent antibody test (IFAT), indirect haemagglutination test (IHA) and real-time PCR, on samples from experimentally inoculated and naturally exposed sheep.

Results

The commercial ELISA detected the infection status in 50% and 100% of sheep orally inoculated with 10,000 T. gondii oocysts (n = 6), from two or three weeks post infection (wpi), respectively, both on serum and plasma samples. Meat juice from all experimentally inoculated sheep collected at slaughter (12 wpi) showed positive ELISA values. In naturally exposed sheep (n = 396), the ELISA showed a very good agreement with IFAT (kappa = 0.91-1.0) and IHA (kappa = 0.96-1.0) performed on serum; and a positive correlation was observed between ELISA values and IFAT titers. By a Receiver Operating Characteristics (ROC) curve analysis, the commercial ELISA had relative sensitivities between 93.33% and 100%, and relative specificities between 96.87% and 100% respect to IFAT and IHA, depending on the considered cut-off value and animal groups tested. Furthermore, the ELISA correctly recognized all animals reacting positive in real-time PCR. The ELISA results on meat juice agreed with those on serum samples in all experimentally inoculated animals, and in 94 out of 96 (97.9%) naturally exposed sheep, when meat juice was tested at a 1:10 dilution.

Conclusion

The commercial ELISA kit evaluated in this study could represent a valuable tool to improve the surveillance and reporting system for T. gondii in sheep populations at the farm level or for diagnosis at the slaughterhouse, contributing to the control of this widespread zoonosis.

【 授权许可】

   
2013 Glor et al.; licensee BioMed Central Ltd.

【 图 表 】

Figure 1.

Figure 2.

【 参考文献 】

• [1]Dubey JP: Toxoplasmosis in sheep-the last 20 years. Vet Parasitol 2009, 163(1–2):1-14.
• [2]Tenter AM, Heckeroth AR, Weiss LM: Toxoplasma gondii: from animals to humans. Int J Parasitol 2000, 30(12–13):1217-1258.
• [3]Buxton D: Protozoan infections (Toxoplasma gondii, Neospora caninum and Sarcocystis spp.) in sheep and goats: recent advances. Vet Res 1998, 29(3–4):289-310.
• [4]Halos L, Thébault A, Aubert D, Thomas M, Perret C, Geers R, Alliot A, Escotte-Binet S, Ajzenberg D, Dardé ML: An innovative survey underlining the significant level of contamination by Toxoplasma gondii of ovine meat consumed in France. Int J Parasitol 2010, 40(2):193-200.
• [5]Edelhofer R, Prossinger H: Infection with Toxoplasma gondii during pregnancy: seroepidemiological studies in Austria. Zoonoses Public Health 2010, 57(1):18-26.
• [6]Cook AJ, Gilbert RE, Buffolano W, Zufferey J, Petersen E, Jenum PA, Foulon W, Semprini AE, Dunn DT: Sources of Toxoplasma infection in pregnant women: European multicentre case–control study. European Research Network on Congenital Toxoplasmosis. BMJ 2000, 321(7254):142-147.
• [7]Dubey JP: Toxoplasmosis of Animals and Humans. 2nd edition. Boca Raton, Florida: CRC Press; 2009.
• [8]Villena I, Durand B, Aubert D, Blaga R, Geers R, Thomas M, Perret C, Alliot A, Escotte-Binet S, Thébault A, Boireau P, Halos L: New strategy for the survey of Toxoplasma gondii in meat for human consumption. Vet Parasitol 2012, 183(3–4):203-208.
• [9]European Food Safety Authority (EFSA): Scientific Opinion of the Panel on Biological Hazards on a request from EFSA on Surveillance and monitoring of Toxoplasma in humans, foods and animals. The EFSA Journal 2007, 583:1-64.
• [10]Juránková J, Opsteegh M, Neumayerová H, Kovarcik K, Frencová A, Baláz V, Volf J, Koudela B: Quantification of Toxoplasma gondii in tissue samples of experimentally infected goats by magnetic capture and real-time PCR. Vet Parasitol 2013, 193(1-3):95-99.
• [11]Berger-Schoch AE, Herrmann DC, Schares G, Müller N, Bernet D, Gottstein B, Frey CF: Prevalence and genotypes of Toxoplasma gondii in feline faeces (oocysts) and meat from sheep, cattle and pigs in Switzerland. Vet Parasitol 2011, 177(3–4):290-297.
• [12]Cassaing S, Bessières MH, Berry A, Berrebi A, Fabre R, Magnaval JF: Comparison between two amplification sets for molecular diagnosis of toxoplasmosis by real-time PCR. J Clin Microbiol 2006, 44(3):720-724.
• [13]World Health Organization (OIE): Principles and methods of validation of diagnostic assays for infectious diseases. 2012. [OIE Manual of Diagnostic Tests and Vaccines for Terrestrial Animals] Access on-line February 2013
• [14]Swets JA: Measuring the accuracy of diagnostic systems. Science 1988, 240(4857):1285-1293.
• [15]Gamble HR, Dubey JP, Lambillotte DN: Comparison of a commercial ELISA with the modified agglutination test for detection of Toxoplasma infection in the domestic pig. Vet Parasitol 2005, 128(3–4):177-181.
• [16]da Silva AV, Langoni H: The detection of Toxoplasma gondii by comparing cytology, histopathology, bioassay in mice, and the polymerase chain reaction (PCR). Vet Parasitol 2001, 97(3):191-198.
• [17]Ragozo AM, Yai RL, Oliveira LN, Dias RA, Dubey JP, Gennari SM: Seroprevalence and isolation of Toxoplasma gondii from sheep from Sao Paulo state. Brazil. J Parasitol 2008, 94(6):1259-1263.
• [18]Dumètre A, Ajzenberg D, Rozette L, Mercier A, Dardé ML: Toxoplasma gondii infection in sheep from Haute-Vienne, France: seroprevalence and isolate genotyping by microsatellite analysis. Vet Parasitol 2006, 142(3–4):376-379.
• [19]Zia-Ali N, Fazaeli A, Khoramizadeh M, Ajzenberg D, Dardé M, Keshavarz-Valian H: Isolation and molecular characterization of Toxoplasma gondii strains from different hosts in Iran. Parasitol Res 2007, 101(1):111-115.
• [20]Dubey JP, Sundar N, Hill D, Velmurugan GV, Bandini LA, Kwok OC, Majumdar D, Su C: High prevalence and abundant atypical genotypes of Toxoplasma gondii isolated from lambs destined for human consumption in the USA. Int J Parasitol 2008, 38(8–9):999-1006.
• [21]Dubey JP, Beattie CP: Toxoplasmosis of Animals and Man. 1st edition. Boca Raton, Florida: CRC; 1988.
• [22]Dubey JP, Thulliez P, Powell EC: Toxoplasma gondii in Iowa sows: comparison of antibody titers to isolation of T. gondii by bioassays in mice and cats. J Parasitol 1995, 81(1):48-53.
• [23]Gardner IA, Greiner M, Dubey JP: Statistical evaluation of test accuracy studies for Toxoplasma gondii in food animal intermediate hosts. Zoonoses Public Health 2010, 57(1):82-94.
• [24]Basso W, Hartnack S, Pardini L, Maksimov P, Koudela B, Venturini MC, Schares G, Sidler X, Lewis FI, Deplazes P: Assessment of diagnostic accuracy of a commercial ELISA for the detection of Toxoplasma gondii infection in pigs by comparison with IFAT, TgSAG1-ELISA and Western blot, using a Bayesian latent class approach. Int J Parasitol 2013.
• [25]Wingstrand A, Lind P, Haugegaard J, Henriksen SA, Bille-Hansen V, Sorensen V: Clinical observations, pathology, bioassay in mice and serological response at slaughter in pigs experimentally infected with Toxoplasma gondii. Vet Parasitol 1997, 72(2):129-140.
• [26]Berger-Schoch AE, Bernet D, Doherr MG, Gottstein B, Frey CF: Toxoplasma gondii in Switzerland: a serosurvey based on meat juice analysis of slaughtered pigs, wild boar, sheep and cattle. Zoonoses Public Health 2011, 58(7):472-478.
• [27]Hartley WJ, Moyle GG: Further observations on the epidemiology of ovine Toxoplasma infection. Aust J Exp Biol Med Sci 1974, 52(4):647-653.
• [28]Dubey JP, Sharma SP: Parasitemia and tissue infection in sheep fed Toxoplasma gondii oocysts. J Parasitol 1980, 66(1):111-114.
• [29]Esteban-Redondo I, Maley SW, Thomson K, Nicoll S, Wright S, Buxton D, Innes EA: Detection of T. gondii in tissues of sheep and cattle following oral infection. Vet Parasitol 1999, 86(3):155-171.
• [30]Kijlstra A, Jongert E: Toxoplasma-safe meat: close to reality? Trends Parasitol 2009, 25(1):18-22.