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International audience; Different transmission routes, including the ingestion of undercooked meat, can result in Toxoplasma gondii infection in humans. The development of effective prevention strategies is hampered by a lack of quantitative information on the contamination level of different types of meat. Therefore, we developed a method for detection and quantification of T. gondii. The method involved preparation of crude DNA extract from hundred gram samples of meat, magnetic capture of T. gondii DNA and, quantitative real-time PCR targeting the T. gondii 529-bp repeat element. The detection limit of this assay was approximately 230 tachyzoites per 100 g of meat sample. There was a linear relation between the number of parasites added to the samples and Cp-values. Results obtained with the PCR method were comparable to bioassay results for experimentally infected pigs, and to serological findings for sheep. In addition, the T. gondii in 50% of the positive sheep samples could be genotyped by sequencing of the GRA6 gene, after isolation of the gene by magnetic capture. Two subtypes of GRA6 type II were identified in the 16 samples from sheep. For seven samples, the identification of T. gondii as type II was confirmed by microsatellite typing. The PCR method can be used as an alternative to bioassay for detection and genotyping of T. gondii, and to quantify the organism in meat samples of various sources.

International audience

One-third of the human world population is infected with the protozoan parasite Toxoplasma gondii Toxoplasmosis is an old disease but is still very underreported and neglected disease.

Toxoplasma gondii is an underestimated food borne zoönoses with a human disease burden that probably equals salmonellosis. Modern pig production systems have led to a disappearance of Toxoplasma infections, but a reemergence has recently been observed on animal friendly pig farms. This project provides strong support for a role of rodents in the transfer of Toxoplasma infection to the pigs on such farms. Rodent control should be included in the quality assurance programs of animal friendly production systems. Toxoplasma gondii is een onderschatte voedsel gerelateerde zoönose waarvan de ziektelast voor de mens waarschijnlijk gelijk is aan salmonellose. Modernisering van de varkenshouderij heeft geleid tot een verdwijning van Toxoplasma infecties, maar een heropleving is recent geconstateerd in de welzijnsvriendelijke varkenshouderij. Dit project geeft sterke aanwijzingen dat plaagdieren een rol kunnen spelen bij de overdracht van Toxoplasma op de varkens van dergelijke bedrijven. Plaagdierbestrijding dient opgenomen te worden in de kwaliteitssystemen voor de welzijnsvriendelijke varkenshouderij.