Franzen C, Müller A, Hegener P, Salzberger B, Hartmann P, Fätkenheuer G, Diehl V, Schrappe M
Department of Internal Medicine I, University of Cologne, Germany.
J Clin Microbiol. 1995 Sep;33(9):2294-6. doi: 10.1128/jcm.33.9.2294-2296.1995.
Intestinal microsporidiosis has been implicated as a major cause of chronic diarrhea in human immunodeficiency virus (HIV)-infected patients. So far diagnosis depends on direct visualization of the parasites by light and transmission electron microscopy. We evaluated the diagnostic value of microsporidian DNA amplification by PCR on duodenal biopsy specimens obtained from patients with and without intestinal microsporidiosis caused by Enterocytozoon bieneusi. Thirteen HIV-infected patients (all CDC stage C3) were studied. Eight patients had intestinal microsporidiosis caused by E. bieneusi (n = 6), Septata intestinalis (n = 1), and Encephalitozoon cuniculi (n = 1); microsporidioses were diagnosed by light microscopy of stool samples and confirmed by light and electron microscopy of intestinal biopsy specimens. Five patients had no microsporidia in their stool samples or in their intestinal biopsy specimens, as examined by light and electron microscopy. Additionally, DNA prepared from Toxoplasma gondii derived from mouse ascites was used as a further control. A 353-bp DNA fragment of the small-subunit rRNA gene could be amplified from all six biopsy specimens infected with E. bieneusi, and the nature of the PCR products was confirmed by Southern blot hybridization. No amplification of DNA fragments was seen by using DNA extracted from biopsy specimens with S. intestinalis or E. cuniculi infection or without microsporidian infection and with template DNA extracted from T. gondii. The results suggest that PCR testing of intestinal biopsy specimens may be a useful approach to diagnosing microsporidiosis in HIV-infected patients.
肠道微孢子虫病被认为是人类免疫缺陷病毒（HIV）感染患者慢性腹泻的主要原因。到目前为止，诊断依赖于通过光学显微镜和透射电子显微镜直接观察寄生虫。我们评估了聚合酶链反应（PCR）扩增微孢子虫DNA对十二指肠活检标本的诊断价值，这些标本取自患有和未患有由比氏肠胞微孢子虫引起的肠道微孢子虫病的患者。对13名HIV感染患者（均为疾病控制中心C3期）进行了研究。8名患者患有由比氏肠胞微孢子虫（n = 6）、肠 septata（n = 1）和兔脑炎微孢子虫（n = 1）引起的肠道微孢子虫病；微孢子虫病通过粪便样本的光学显微镜诊断，并通过肠道活检标本的光学和电子显微镜确诊。5名患者的粪便样本和肠道活检标本经光学和电子显微镜检查均未发现微孢子虫。此外，从鼠腹水来源的刚地弓形虫制备的DNA用作进一步对照。从所有6份感染比氏肠胞微孢子虫的活检标本中均可扩增出小亚基rRNA基因的353 bp DNA片段，PCR产物的性质通过Southern印迹杂交得以证实。使用从感染肠septata或兔脑炎微孢子虫的活检标本或未感染微孢子虫的活检标本中提取的DNA以及从刚地弓形虫中提取的模板DNA，均未观察到DNA片段的扩增。结果表明，对肠道活检标本进行PCR检测可能是诊断HIV感染患者微孢子虫病的一种有用方法。
