The present invention concerns gp36 immunoreactive compositions for E. canis and gp 47 immunoreactive compositions for E. chaffeensis. In particular, epitopes for E. canis gp36 and E. chaffeensis gp 47 are disclosed. In certain embodiments, the immunoreactive compositions comprise tandem repeats having carbohydrate moieties.

Targeted disruption of a specific gene and its subsequent restoration in obligate intracellular bacteria remains extremely challenging due to their absolute requirement for residence inside a host cell to replicate. Here, targeted allelic exchange mutations were created to inactivate two genes and then to restore one of the two genes of a rickettsial pathogen, Ehrlichia chaffeensis. These methods were then also successfully utilized in Ehrlichia canis and Anaplasma phagocyophilum. The resultant mutated pathogens are useful in immunogenic compositions for reducing the incidence of or severity of infection with ricksettsial pathogens.

Nucleic acids include sequences encoding Ehrlichia ruminantium epitopes which induce a CD4 immune response, and sequences encoding Ehrlichia ruminantium epitopes which induce a CD8 immune response. Multi-epitope DNA vaccines include the nucleic acids and polypeptides are encoded by the nucleic acids. Methods of eliciting an immune response against heartwater disease in a subject make use of the nucleic acids, multi-epitope DNA vaccines and polypeptides.

Nucleic acids include sequences encoding Ehrlichia ruminantium epitopes which induce a CD4 immune response, and sequences encoding Ehrlichia ruminantium epitopes which induce a CD8 immune response. Multi-epitope DNA vaccines include the nucleic acids and polypeptides are encoded by the nucleic acids. Methods of eliciting an immune response against heartwater disease in a subject make use of the nucleic acids, multi-epitope DNA vaccines and polypeptides.

Provided herein are chimeric polypeptides that may be used, e.g., for the diagnosis of or vaccination against Ehrlichia chaffeensis and/or Ehrlichia canis.

Provided herein are chimeric polypeptides that may be used, e.g., for the diagnosis of or vaccination against Ehrlichia chaffeensis and/or Ehrlichia canis.

The present invention provides antigens, for use in the treatment or prevention of C. burnetii infection. Also provided are nucleic acids encoding such antigens, and antibodies raised against such antigens.

The present invention provides antigens, for use in the treatment or prevention of C. burnetii infection. Also provided are nucleic acids encoding such antigens, and antibodies raised against such antigens.

The present disclosure provides compositions and methods for reducing the incidence of and/or severity of diseases associated with tick-borne pathogens. In preferred forms, the compositions comprise a recombinant antigenic protein subunit that has been glycosylated. Some preferred subunits include the MAP1 protein of Ehrlichia ruminantium, the p30-1 sequence from Ehrlichia canis, the p28-Omp19 protein from Ehrlichia chaffeensis, and the MSP4 protein from Anaplasma marginale. Administration of such compositions to an animal in need thereof provides protection against clinical signs of infection in susceptible animals.

The present disclosure provides compositions and methods for reducing the incidence of and/or severity of diseases associated with tick-borne pathogens. In preferred forms, the compositions comprise a recombinant antigenic protein subunit that has been glycosylated. Some preferred subunits include the MAP1 protein of Ehrlichia ruminantium, the p30-1 sequence from Ehrlichia canis, the p28-Omp19 protein from Ehrlichia chaffeensis, and the MSP4 protein from Anaplasma marginale. Administration of such compositions to an animal in need thereof provides protection against clinical signs of infection in susceptible animals.