Gupta Rashmi, Mirdha Bijay Ranjan, Guleria Randeep, Kumar Lalit, Samantaray Jyotish Chandra, Agarwal Sanjay Kumar, Kabra Sushil Kumar, Luthra Kalpana
Department of Microbiology, All Indian Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India.
Diagn Microbiol Infect Dis. 2009 Aug;64(4):381-8. doi: 10.1016/j.diagmicrobio.2009.04.008.
A total of 327 clinical specimens, including both invasive and noninvasive samples, obtained from 275 patients with various types of underlying immunocompromised conditions and a clinical suspicion of Pneumocystis pneumonia (PCP) were subjected to 2 different nested polymerase chain reaction (PCR) assays. The target genes used for nested PCR were mitochondrial large subunit ribosomal RNA (mtLSU rRNA) and internal transcribed spacer (ITS) region. The results were compared with a single-round PCR targeting major surface glycoprotein (MSG) gene. Amplification was successful in 16% of cases by mtLSU rRNA nested PCR, in 14.5% by ITS nested PCR, and in 10.9% by MSG PCR. The nested mtLSU rRNA PCR was found to be more sensitive (100% sensitive and 98.7% specific) and useful in detecting PCP for its use in routine diagnosis in our settings. Thus, this assay may be quite useful in the identification of patients who are in the early stage of Pneumocystis jirovecii infection with an organism load that could not be easily detected by the single-step PCR.
从275例患有各种潜在免疫功能低下疾病且临床怀疑患有肺孢子菌肺炎（PCP）的患者身上获取了总共327份临床标本，包括侵袭性和非侵袭性样本，并对其进行了两种不同的巢式聚合酶链反应（PCR）检测。用于巢式PCR的靶基因是线粒体大亚基核糖体RNA（mtLSU rRNA）和内部转录间隔区（ITS）区域。将结果与靶向主要表面糖蛋白（MSG）基因的单轮PCR进行比较。通过mtLSU rRNA巢式PCR，16%的病例扩增成功；通过ITS巢式PCR，14.5%的病例扩增成功；通过MSG PCR，10.9%的病例扩增成功。发现巢式mtLSU rRNA PCR在我们的环境中用于常规诊断时，对检测PCP更敏感（敏感性为100%，特异性为98.7%）且有用。因此，该检测方法在鉴定处于耶氏肺孢子菌感染早期且病原体载量难以通过单步PCR轻易检测到的患者时可能非常有用。
