Yagi Shigeo, Schuster Frederick L, Visvesvara Govinda S
California Department of Public Health, Viral and Rickettsial Disease Laboratory, 850 Marina Bay Parkway, Richmond, CA, 94804, USA.
Parasitol Res. 2008 Jan;102(2):211-7. doi: 10.1007/s00436-007-0749-7. Epub 2007 Sep 25.
Granulomatous amoebic encephalitis (GAE) is a usually fatal disease caused by the free-living amoebae Balamuthia mandrillaris and Acanthamoeba spp. The intent of this study was to determine if the polymerase chain reaction (PCR) could be used retrospectively to detect amoeba mitochondrial 16S ribosomal ribonucleic acid gene deoxyribonucleic acid (DNA) in confirmed archival tissue sections from GAE cases stored in our laboratories for 1 to 34 years. The DNA was extracted from deparaffinized sections, and appropriate primer sets for each of the two amoebae were used for DNA detection. Indirect immunofluorescent staining (IIF) of tissue sections was used as the standard for identification of amoebae against which the PCR results were compared. Sixty slides from a total of 56 cases were processed by PCR for amoeba 16S DNA. In 28 (47%) slides, there was agreement between the IIF and PCR results. In 41 of the slides (52%), no DNA was detected after PCR. In one slide (1%), the PCR and IIF results did not agree. While PCR supported IIF findings in about half of the slides, there are significant limitations in amoeba DNA identifications in formalin-fixed brain tissues. Degradation of amoeba DNA because of formalin fixation was probably a factor in limiting valid results.
肉芽肿性阿米巴脑炎（GAE）是一种通常致命的疾病，由自由生活的阿米巴原虫——曼氏巴罗属阿米巴和棘阿米巴属引起。本研究的目的是确定聚合酶链反应（PCR）是否可用于回顾性检测保存在我们实验室1至34年的GAE确诊病例存档组织切片中的阿米巴线粒体16S核糖体核糖核酸基因的脱氧核糖核酸（DNA）。从脱石蜡切片中提取DNA，并使用针对这两种阿米巴原虫各自的合适引物组进行DNA检测。组织切片的间接免疫荧光染色（IIF）用作鉴定阿米巴原虫的标准，并与PCR结果进行比较。对总共56例病例的60张载玻片进行了PCR检测阿米巴16S DNA。在28张（47%）载玻片中，IIF和PCR结果一致。在41张（52%）载玻片中，PCR后未检测到DNA。在1张（1%）载玻片中，PCR和IIF结果不一致。虽然PCR在大约一半的载玻片中支持了IIF的结果，但在福尔马林固定的脑组织中进行阿米巴DNA鉴定存在显著局限性。福尔马林固定导致的阿米巴DNA降解可能是限制有效结果的一个因素。
