用聚合酶链反应（PCR）检测支气管肺泡灌洗（BAL）液中的嗜肺军团杆菌

本文研究了由嗜肺军团杆菌的巨噬细胞感染性增效子（ｍｉｐ）基因设计的一对引物，用ＰＣＲ扩增嗜肺军团杆菌３、５、７、８血清型的４个标准菌株的特异ＤＮＡ序列，研究了用该引物扩增ＢＡＬ液中嗜肺军团菌特异ＤＮＡ序列的方法、灵敏度及特异性。结果表明：用上述引物扩增嗜肺军团菌４个标准菌株的ＤＮＡ，均可得到２０７ｂｐ的特异扩增产物，ＢＡＬ液中的军团菌经离心及裂解液裂解后，可直接进行ＤＮＡ扩增，当ＢＡＬ与液中军团菌量为２×１０３ＣＦＵ／ｍｌ时，即可检测出特异扩增带（电泳法），除军团菌外，其它受试细菌均无此特异性扩增，用本法对４２例临床非典型肺炎患者的ＢＡＬ液进行嗜肺军团菌的检测，在４２份嗜肺军团菌培养均为阴性的ＢＡＬ液中，其中一例ＰＣＲ检测军团菌为阳性。本研究提示：用ＰＣＲ检测ＢＡＬ液中的军团菌是可行的，并有快速、灵敏、特异之忧点。

DETECTION OF LEGIONEIIA NEUMOPHILA IN BRONCHOALVEOLAR LAVAGE FLUID BY POLYMERASE CHAIN REACTION

By using primers according to the macrophage infectivitypotentiator(mip)gene of Legionella pneumophila,a specific DNAfragment(207 bp)can be amplified from 4 L. pneumophila strains(serogroup 3,5,7,8)and from L.pneumophila in bronchoalveolar lavage(BAL)fluid.There was not the specific amplification DNA if thetemplates were from other bacteria tested. After optimization of theconditions for DNA extraction from BAL fluid,a 1.5 ml BAL fluidseeded with L. pneumophila 2x103CFU/ml tested positive afteramplification.A total of 42 BAL fluid specimens from patients withsevere atypical pneumonia were used to detect L. pneumophila by thisprocedure. Among 42 culture-negative samples one sample was posi-tiveafter amplification. This result shows that it is available to detect L.pneumophila in BAL fluid by PCR.