Use of attenuated strains of parasites for the prevention or treatment of pathologies associates with an apicomplexan

1. Method for the prevention or the treatment, in a neonate mammal, of a pathology associated with an apicomplexan of the family of Cryptosporidiidae, comprising a step of administration, to said neonate mammal, of strains of Sarcocystidae selected from Toxoplasma spp or Neospora spp isolated from their natural environment and having an immunostimulant effect.

2. Method for the prevention or the treatment, in a neonate mammal, of a pathology associated with an apicomplexan of the family of Cryptosporidiidae according to claim 1 , in which said mammal is a human being or an animal.

3. Method for the prevention or the treatment, in a neonate mammal, of a pathology associated with an apicomplexan of the family of Cryptosporidiidae according to claim 2 , in which said animal belongs to the group comprising or constituted by ovines, caprines, porcines, bovines, equines, camelids, canids or felids.

4. Method for the prevention or the treatment, in a neonate mammal, of a pathology associated with an apicomplexan of the family of Cryptosporidiidae according to claim 1 , in which said strains of Toxoplasma spp or of Neospora spp have at least an adhesin MIC-1 and/or an adhesin MIC-3 inactivated by a genetic modification relating to at least one of the mic-1 and/or mic-3 genes.

5. Method for the prevention or the treatment, in a neonate mammal, of a pathology associated with an apicomplexan of the family of Cryptosporidiidae according to claim 1 , in which said strains of Toxoplasma spp or of Neospora spp have the two adhesins MIC-1 and MIC-3 inactivated by a genetic modification relating to the two mic-1 and mic-3 genes.

6. Method for the prevention or the treatment, in a neonate mammal, of a pathology associated with an apicomplexan of the family of Cryptosporidiidae according to claim 4 , in which the strains of Toxoplasma spp or of Neospora spp are respectively Toxoplasma gondii or Neospora caninum.

7. Method for the prevention or the treatment, in a neonate mammal, of a pathology associated with an apicomplexan of the family of Cryptosporidiidae according to claim 1 , in which the immunostimulant effect of said strains leads to the secretion of interleukin-12 (IL-12) and then of interferon-γ (IFN-γ).

8. Method for the prevention or the treatment, in a neonate mammal, of a pathology associated with an apicomplexan of the family of Cryptosporidiidae according to claim 7 , in which the secretion of interleukin-12 (IL-12) and of interferon-γ (IFN-γ) begins between 3 and 9 days after using said strains of Toxoplasma spp or of Neospora spp as immunostimulant.

9. Method for the prevention or the treatment, in a neonate mammal, of a pathology associated with an apicomplexan of the family of Cryptosporidiidae according to claim 1 , in which said pathology associated with an apicomplexan of the family Cryptosporidiidae is cryptosporidiosis.

10. Method for the prevention or the treatment, in a neonate mammal, of a pathology associated with an apicomplexan of the family of Cryptosporidiidae according to claim 9 , in which the apicomplexan of the family Cryptosporidiidae responsible for the cryptosporidiosis is at least one apicomplexan selected from the group constituted by Cryptosporidium parvum, Cryptosporidium bovis, Cryptosporidium andersoni, Cryptosporidium ryanae, Cryptosporidium muris, Cryptosporidium ubiquitum, Cryptosporidium hominis, Cryptosporidium canis, Cryptosporidium felis, Cryptosporidium baileyi, Cryptosporidium meleagridis or Cryptosporidium xiaoi.

11. Method for the prevention or the treatment, in a neonate mammal, of a pathology associated with an apicomplexan of the family of Cryptosporidiidae according to claim 6 , comprising a step of administration, to said neonate mammal, of strains of Toxoplasma gondii or Neospora caninum isolated from their natural environment and having an immunostimulant effect, said strains of Toxoplasma gondii or of Neospora caninum having the two adhesins MIC-1 and MIC-3 inactivated by a genetic modification relating to the two mic-1 and mic-3 genes, in which said pathology associated with an apicomplexan of the family Cryptosporidiidae is cryptosporidiosis.

12. Method for the prevention or the treatment, in a neonate mammal, of a pathology associated with an apicomplexan of the family of Cryptosporidiidae according to claim 6 , comprising a step of administration, to said neonate mammal, of strains of Toxoplasma gondii or Neospora caninum isolated from their natural environment and having an immunostimulant effect, said strains of Toxoplasma gondii or of Neospora caninum having the two adhesins MIC-1 and MIC-3 inactivated by a genetic modification relating to the two mic-1 and mic-3 genes, in which said strains of Toxoplasma gondii or of Neospora caninum are administered to the mammal at a rate from 20 to 10 9 tachyzoites.

13. Method for the prevention or the treatment, in a neonate mammal, of a pathology associated with an apicomplexan of the family of Cryptosporidiidae according to claim 1 , in which said strains are in a galenic form comprising or constituted by liquid suspensions, solid or liquid dispersions, powders, pastes or lyophilizates.

14. Method for the prevention or the treatment, in a neonate mammal, of a pathology associated with an apicomplexan of the family of Cryptosporidiidae according to claim 1 , in which said strains are associated with at least one other antigen, or at least one adjuvant, or at least one stabilizer, or at least one preservative or a mixture of at least two of said products for increasing the immune response of said mammal.

15. Method for the prevention or the treatment, in a neonate mammal, of a pathology associated with an apicomplexan of the family of Cryptosporidiidae according to claim 5 , in which the strains of Toxoplasma spp or of Neospora spp are respectively Toxoplasma gondii or Neospora caninum.