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.

The present invention concerns gp19 immunoreactive compositions for E. canis and compositions related thereto, including vaccines, antibodies, polypeptides, peptides, and polynucleotides. In particular, epitopes for E. canis gp19 are disclosed.

The present invention concerns VLPT immunoreactive compositions for E. chaffeensis and compositions related thereto, including vaccines, antibodies, polypeptides, peptides, and polynucleotides. In particular, epitopes for E. chaffeensis VLPT are disclosed.

The present invention concerns VLPT immunoreactive compositions for E. chaffeensis and compositions related thereto, including vaccines, antibodies, polypeptides, peptides, and polynucleotides. In particular, epitopes for E. chaffeensis VLPT are disclosed.

The present invention concerns VLPT immunoreactive compositions for E. chaffeensis and compositions related thereto, including vaccines, antibodies, polypeptides, peptides, and polynucleotides. In particular, epitopes for E. chaffeensis VLPT are disclosed.

The present invention concerns VLPT immunoreactive compositions for E. chaffeensis and compositions related thereto, including vaccines, antibodies, polypeptides, peptides, and polynucleotides. In particular, epitopes for E. chaffeensis VLPT are disclosed.

Disclosed are vaccines containing one or more immunogenic polypeptides derived from an EtpE protein from an Ehrlichia sp. or nucleic acid encoding these polypeptides. Also disclosed is a method for vaccinating a subject against Ehrlichia sp. that involves administering to the subject a composition comprising any of the disclosed vaccines. Also disclosed is a method for diagnosing and/or monitoring the treatment of Ehrlichiosis in a subject that comprising assaying a biological sample (e.g., blood, serum, or plasma sample) from the subject for the presence of an antibody that specifically binds an EtpE polypeptide. Also disclosed are methods for delivering a therapeutic or diagnostic agent to a cell in a subject that involves conjugating the agent, or a delivery vehicle comprising the agent, to polypeptide containing the C-terminal domain of an EtpE protein.

The present invention provides an isolated and purified heat shock protein 60 (Hsp60) peptide having the amino acid sequence of SEQ ID NO:2. The instant invention is also directed to a vaccine against Ehrlichia comprising a peptide homologous to the amino acid sequence of SEQ ID NO:2. The instant invention is also directed to an antibody directed against a peptide homologous to the amino acid sequence of SEQ ID NO:2. The instant invention is also directed to a method of determining whether a subject is infected with Ehrlichia, comprising the steps of: contacting a sample from a subject with the antibody described herein; and detecting a resulting antibody reaction, wherein a positive reaction indicates the subject is infected with Ehrlichia.

The present invention provides an isolated and purified heat shock protein 60 (Hsp60) peptide having the amino acid sequence of SEQ ID NO:2. The instant invention is also directed to a vaccine against Ehrlichia comprising a peptide homologous to the amino acid sequence of SEQ ID NO:2. The instant invention is also directed to an antibody directed against a peptide homologous to the amino acid sequence of SEQ ID NO:2. The instant invention is also directed to a method of determining whether a subject is infected with Ehrlichia, comprising the steps of: contacting a sample from a subject with the antibody described herein; and detecting a resulting antibody reaction, wherein a positive reaction indicates the subject is infected with Ehrlichia.

Immunoreactive engineered polypeptides are provided. The engineered polypeptides can be used to diagnose or induce an immune response against E. chaffeensis or E. canis.