Diagnosis and isolation of Toxoplasma gondii in horses from Brazilian slaughterhouses.
Abstract: This study aimed to investigate anti-Toxoplasma gondii antibodies and to isolate the parasite from the brains of horses processed at slaughterhouses in Brazil. We collected brain and blood samples from 398 horses of various ages, from six Brazilian states. Serum samples were evaluated by indirect fluorescent antibody test (IFAT cut-off titre ≥ 1:64), and brains were submitted to mouse bioassay. Among the 398 horses, positivity for T. gondii was identified in 46 (11.6%) by IFAT and in 14 (3.5%) by mouse bioassay. In 12 of those 14 bioassays, mice were positive only by IFAT (cut-off titre ≥ 1:16), T. gondii being isolated in the remaining two. Using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of 18S rDNA to differentiate among T. gondii, Neospora caninum, and Sarcocystis neurona, we found that two of the 14 brains were positive for T. gondii only. For genotyping of the two isolates and the PCR-positive brain, we performed PCR-RFLP based on 13 markers, and SAG2 all samples were Toxoplasma gondii type I. Collectively, IFAT of horse sera and mouse bioassay identified positivity in 60 (15%) of the samples. Our results show that some horses sent to slaughter in Brazil have been exposed to T. gondii.
Publication Date: 2013-03-19 PubMed ID: 23538498DOI: 10.1590/s1984-29612013005000009Google Scholar: Lookup
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- Journal Article
Summary
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The study examines the presence of Toxoplasma gondii, a type of parasite, in horses from Brazilian slaughterhouses through tests on brain and blood samples. The results show a small portion of the horses studied have been exposed to this parasite.
Methodology
- The research involved collecting brain and blood samples from 398 horses of various ages. These horses were sourced from slaughterhouses in six Brazilian states.
- The obtained serum samples were thoroughly analysed using an indirect fluorescent antibody test, also known as IFAT. A titre of 1:64 or above was considered the cut-off for confirming the presence of T. gondii antibodies.
- The brain samples were tested using mouse bioassay where live mice were exposed to the horse brain samples to see if the parasite would infect them.
Data Observations
- Out of the 398 horses examined, antibodies for T. gondii were detected in 46 (11.6%) through the IFAT test.
- Through the mouse bioassay test, only 14 (3.5%) of horses’ brain samples showed positivity for T. gondii.
- In the 14 positive bioassay cases, IFAT showed positivity in 12, with T. gondii isolated in the remaining two.
- Further testing using PCR-RFLP analysis of 18S rDNA revealed that only two of the 14 brain samples showed T. gondii exclusively, whereas the others were either negative or presented co-infections.
Typing and Genotyping
- To identify the specific type of T. gondii found, researchers performed PCR-RFLP based on 13 markers. They found that all samples that were tested positive belonged to Toxoplasma gondii type I.
- The collective outcome of IFAT and mouse bioassay revealed 60 (15%) positive samples, indicating the exposure to T. gondii.
Conclusion
- The results of this survey indicate that a percentage of the horses sent for slaughter in Brazil are infected with T. gondii. This suggests the necessity for more thorough screening and investigations in Brazilian slaughterhouses.
Cite This Article
APA
Evers F, Garcia JL, Navarro IT, Zulpo DL, Nino Bde S, Ewald MP, Pagliari S, Almeida JC, Freire RL.
(2013).
Diagnosis and isolation of Toxoplasma gondii in horses from Brazilian slaughterhouses.
Rev Bras Parasitol Vet, 22(1), 58-63.
https://doi.org/10.1590/s1984-29612013005000009 Publication
Researcher Affiliations
MeSH Terms
- Abattoirs
- Animals
- Antibodies, Protozoan / blood
- Brazil
- Horse Diseases / blood
- Horse Diseases / diagnosis
- Horse Diseases / parasitology
- Horses
- Toxoplasma / immunology
- Toxoplasma / isolation & purification
- Toxoplasmosis, Animal / blood
- Toxoplasmosis, Animal / diagnosis
Citations
This article has been cited 11 times.- Rossi GAM, de Freitas Costa E, Gabriël S, Braga FR. A Systematic Review and Meta-Analysis on the Occurrence of Toxoplasmosis in Animals Slaughtered in Brazilian Abattoirs. Animals (Basel) 2022 Nov 10;12(22).
- Stelzer S, Basso W, Benavides Silván J, Ortega-Mora LM, Maksimov P, Gethmann J, Conraths FJ, Schares G. Toxoplasma gondii infection and toxoplasmosis in farm animals: Risk factors and economic impact. Food Waterborne Parasitol 2019 Jun;15:e00037.
- Pena HFJ, Pinheiro TM, Soares HS, Oliveira S, Alves BF, Ferreira MN, Gennari SM. Typical Brazilian genotype of Toxoplasma gondii isolated from a horse destined for human consumption in Europe from a slaughterhouse. Parasitol Res 2018 Oct;117(10):3305-3308.
- Klun I, Uzelac A, Villena I, Mercier A, Bobić B, Nikolić A, Rajnpreht I, Opsteegh M, Aubert D, Blaga R, van der Giessen J, Djurković-Djaković O. The first isolation and molecular characterization of Toxoplasma gondii from horses in Serbia. Parasit Vectors 2017 Apr 4;10(1):167.
- Razmi GR, Abedi V, Yaghfoori S. Serological study of Toxoplasma gondii infection in Turkoman horses in the North Khorasan Province, Iran. J Parasit Dis 2016 Jun;40(2):515-9.
- Belluco S, Mancin M, Conficoni D, Simonato G, Pietrobelli M, Ricci A. Investigating the Determinants of Toxoplasma gondii Prevalence in Meat: A Systematic Review and Meta-Regression. PLoS One 2016;11(4):e0153856.
- Bryan LK, Hamer SA, Shaw S, Curtis-Robles R, Auckland LD, Hodo CL, Chaffin K, Rech RR. Chagas disease in a Texan horse with neurologic deficits. Vet Parasitol 2016 Jan 30;216:13-7.
- Aroussi A, Vignoles P, Dalmay F, Wimel L, Dardé ML, Mercier A, Ajzenberg D. Detection of Toxoplasma gondii DNA in horse meat from supermarkets in France and performance evaluation of two serological tests. Parasite 2015;22:14.
- Miao Q, Wang X, She LN, Fan YT, Yuan FZ, Yang JF, Zhu XQ, Zou FC. Seroprevalence of Toxoplasma gondii in horses and donkeys in Yunnan Province, Southwestern China. Parasit Vectors 2013 Jun 6;6:168.
- Ullah A, Geng M, Chen W, Zhu Q, Shi L, Zhang X, Akhtar MF, Wang C, Khan MZ. Effect of Parasitic Infections on Hematological Profile, Reproductive and Productive Performance in Equines. Animals (Basel) 2025 Nov 14;15(22).
- de Oliveira UV, Varjão JL, de Jesus Deiró AG, Maciel BM, Silva FL, Pinheiro AM, Gondim LFP, Munhoz AD. Isolation of Toxoplasma gondii from the masseter muscles of equines destined for human consumption in a slaughterhouse in southern Brazil. J Parasit Dis 2025 Mar;49(1):121-129.
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