It is related this invention, to the polynucleotide array which the new Lawsonia intracellularis polypeptide the code is done. In addition as for that, the DNA fragment which includes these arrays, it is related to rearrangement plasmid DNA, and the rearrangement microbe which lives. Furthermore, it is related this invention, to the polypeptide which the code is done by these nucleotide arrays. In addition as for this invention, it is related to the manner of preparing the immunogenicity constituent, and these immunogenicity constituents for preventing the Lawsonia intracellularis infection. In addition as for this invention, it is related to the diagnostic test for the detecting Lawsonia intracellularisDNA, detection of the Lawsonia intracellularis antigen, and detection of the antibody for Lawsonia intracellularis.本発明は、新規Lawsonia intracellularisポリペプチドをコードするポリヌクレオチド配列に関連する。それはまた、これらの配列を含むDNA断片、組換えプラスミドDNA、および生きた組換え微生物に関連する。さらに、本発明は、これらのヌクレオチド配列によってコードされるポリペプチドに関連する。本発明はまた、Lawsonia intracellularis感染の予防のための免疫原性組成物、およびこれらの免疫原性組成物の調製の方法に関連する。本発明はまた、Lawsonia intracellularisDNAの検出、Lawsonia intracellularis抗原の検出、およびLawsonia intracellularisに対する抗体の検出のための診断テストに関連する。