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.
