To detect Lawsonia intracellularis (LI) which cause Porcine proliferative enteritis (PPE), a PCR detection method was developed with a pair of specific primers for amplification of a 294 bp DNA product from LI DNA extracted by guanidine thiocyanate-diatomaceous earth (GuSCN-DE).The test results indicated that limit detection for LI DNA was 1.7 × 102 copies and no amplification for E.coli, Salmonella, coronavirus, and pseudorabies virus.Tested on 102 clinic fecal and mucosal samples, the positive rate was 12.75％ by PCR detection and the coincidence rate was 88.04％, comparing with the commercial ELISA kit for LI detection.This assay could be used for LI rapid detection and PPE diagnosis.%为建立一种适用于临床检测胞内劳森氏茵(Lawsonia intracellularis,LI)的检测方法,本研究通过比较提取粪便样品基因组DNA的不同方法,结合PCR方法特异性扩增aspA基因检测临床样品中的LI.敏感性试验表明,阳性样本最低检出量为1.7×102 copie/μL;特异性试验表明,该方法对大肠杆菌、沙门氏茵、流行性腹泻病毒和伪狂犬病病毒扩增结果均为阴性;对102份临床样品阳性检出率为12.75%,与ELISA试剂盒检测结果符合率达88.04%;不同方法提取粪便样品基因组DNA对PCR检测敏感性的影响结果表明,固相吸附法最低检出量为2.9×102copies/μL,显著优于Chelex-100+Triton X-100法(3.32×103copie/μL)和蛋白酶K-CTAB法(2.45×106copie/μL).因此,固相吸附法结合PCR方法进行检测具有快速、特异、敏感、重复性好等优点,适用于猪增生性肠炎的临床发病诊断及流行病学监测.
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