Method and peptides for the detection of Chlamydia suis

A kit for use in the diagnosis of a Chlamydia suis infection, comprising an isolated peptide of 8 to 30 amino acids long comprising one or more peptides selected from the group consisting of the amino acid sequence of SEQ ID NO:

• 1 (GTKDASID), the amino acid sequence of SEQ ID NO:
• 2 (SQQSSIAS), a sequence at least 75% identical to SEQ ID NO:
• 1, and a sequence at least 75% identical to SEQ ID NO:
• 2, wherein said peptide(s) are immobilized on a solid support.

A method for diagnosing a Chlamydia suis infection comprising

• providing a biological sample from the subject, and
• analyzing the sample for the presence of antibodies against one or more peptides selected from the group consisting of the amino acid sequence of SEQ ID NO:
• 1 (GTKDASID), the amino acid sequence of SEQ ID NO:
• 2 (SQQSSIAS), a sequence at least 75% identical to SEQ ID NO:
• 1, and a sequence at least 75% identical to SEQ ID NO:
• 2, wherein said peptide(s) are immobilized on a solid support, and
• whereby the presence of antibodies to one or more of said peptides is indicative of a Chlamydia suis infection.

A method for differentiating a vaccinated subject from a naturally infected subject, comprising

• providing a biological sample from a subject, and
• analyzing the biological sample for the presence of antibodies against the peptide of SEQ ID NO:
• 1 (GTKDASID), or a peptide of an amino acid sequence being at least 75% identical thereto;
• and/or against a peptide of SEQ ID NO:
• 2 (SQQSSIAS), or a peptide of an amino acid sequence being at least 75% identical thereto,
• wherein the vaccinated subject is a subject vaccinated with a vaccine against Chlamydia suis that does not comprise SEQ ID NO:1 and SEQ ID NO:2,
• wherein the naturally infected subject is a subject infected with Chlamydia suis, and the presence of the antibodies is indicative of a natural Chlamydia suis infection.

A method of preparing a peptide of 8 to 30 amino acids long comprising one or more peptides selected from the group consisting of the amino acid sequence of SEQ ID NO:

• 1 (GTKDASID), the amino acid sequence of SEQ ID NO:
• 2 (SQQSSIAS), a sequence at least 75% identical to SEQ ID NO:
• 1, and a sequence at least 75% identical to SEQ ID NO:
• 2, wherein the peptides are produced by synthetic chemistry, polypeptide hydrolysis or recombinant expression.