Singh H B, Singh Pushpendra, Jadaun G P S, Srivastava K, Sharma V D, Chauhan D S, Sharma S K, Katoch V M
National JALMA Institute for Leprosy and Other Mycobacterial Diseases (ICMR), Tajganj, Agra-282001.
J Commun Dis. 2006 Mar;38(3):274-9.
PCR has emerged as a powerful technique for detection of various pathogens including Mycobacterium tuberculosis. In present study, eighty one samples of lymph node biopsies from clinically suspected cases of tuberculous lymphadenitis were examined for AFB, culture on Löwenstein Jensen medium and simultaneous use of two PCRs targeting IS6110 and MPB64. Positivity with M. tuberculosis culture and AFB was 13.6% and 28.4% respectively. All samples culture positive for nontuberculous mycobacteria were negative by both PCR systems. Higher proportion of positive results were observed with PCR targeting IS6110 by which 56 of 81 (69.1%) samples showed positive results as compared to PCR targeting MPB64 by which 39 of 81 (48.2 %) samples showed positive results. When combined, 63 out of 81 (77.8%) samples were detected positive for M. tuberculosis DNA. However, 7/81 (8.6 %) samples remained negative by IS6110 but positive by MPB64 method. Thus our data suggest that the use of one additional PCR (other than IS6110 system) can reduce false negativity of PCR results in the samples harboring zero copy of IS6110 element which is known to exist in Indian population.
聚合酶链反应（PCR）已成为检测包括结核分枝杆菌在内的各种病原体的强大技术。在本研究中，对81份临床疑似结核性淋巴结炎病例的淋巴结活检样本进行了抗酸杆菌（AFB）检查、在罗 - 琴培养基上培养，并同时使用两种针对IS6110和MPB64的PCR。结核分枝杆菌培养和AFB的阳性率分别为13.6%和28.4%。所有非结核分枝杆菌培养阳性的样本在两种PCR系统中均为阴性。针对IS6110的PCR观察到更高比例的阳性结果，81份样本中有56份（69.1%）呈阳性，而针对MPB64的PCR中，81份样本中有39份（48.2%）呈阳性。两者结合时，81份样本中有63份（77.8%）检测出结核分枝杆菌DNA阳性。然而，7/81（8.6%）的样本通过IS6110检测为阴性，但通过MPB64方法检测为阳性。因此，我们的数据表明，使用一种额外的PCR（IS6110系统以外）可以减少IS6110元件零拷贝样本中PCR结果的假阴性，已知这种情况在印度人群中存在。
