Aoki M, Katayama T, Yamagishi F, Yokota S, Kameda K, Saito H, Hara K, Ezaki T, Kawai T, Yotsumoto H
Research Institute of Tuberculosis, JATA, Tokyo, Japan.
Kekkaku. 1994 Oct;69(10):593-605.
Recently, a new kit to detect and identify mycobacteria in clinical specimens was developed by Japan Roche Co. Limited. The new method is based on amplification of DNA of mycobacteria in clinical specimens by PCR and hybridization of amplified DNA by microwell plate hybridization method, which is the "Amplicor Mycobacteria, Roche, (AMP-M)". Cooperative study was organized with 15 tuberculosis hospitals and institutions throughout Japan, and 349 clinical specimens from newly admitted tuberculosis patients and/or suspects were collected during July and August, 1993. All the specimens were examined by smear microscopy (Ziehl-Neelsen's staining), culture on Ogawa egg media, culture on variant 7H9 liquid media and by AMP-M. Excluding 25 specimens which had failed to identify the species of mycobacteria because of contamination, disability to multiply on the transplanted solid media and so on, the results of the examinations in 324 specimens consisting of 167 specimens from previously untreated cases and those of 157 specimens from previously treated cases were analysed. Main results obtained were as follows; 1. Of 70 smear positive specimens from previously untreated cases, culture positive on Ogawa media and 7H9 media, and by AMP-M positive were 59 (84.3%), 61 (87.1%) and 66 (94.3%), respectively. Of 97 smear negative specimens, culture positive were 20 (20.6%), 22 (22.7%) and 27 (27.8%), respectively. The AMP-M showed the highest positive rate in both groups. 2. The sensitivity and the specificity of AMP-M in previously untreated cases were calculated by assuming that positive on Ogawa and/or variant 7H9 media is "positive". The sensitivity was 95.8% (68/71) and the specificity was 94.8% (91/96) for M. tuberculosis in previously untreated cases. The sensitivity and the specificity for M. avium and M. intracellulare were all 100%, although the numbers observed were small. 3. So-called false positive of the AMP-M were observed in 5 cases out of 96 culture negatives on both Ogawa and variant 7H9 media. However, all 5 cases were positive by repeated AMP-M, 3 become culture positive later, and another 2 showed clinical findings consistent with tuberculosis. Hence, the authors considered that the false positive rate of the AMP-M method is to be very low in previously untreated cases. 4. Of 86 smear positive cases with history of previous chemotherapy, the positive culture on Ogawa media, variant 7H9 media and that by AMP-M method were 64 (74.4%), 77 (89.5%) and 85 (98.8%), respectively. In the smear negative cases, culture positive was 10 out of 71 (14.1%), 13 (18.3%) and 24 (33.8%), respectively.
最近，日本罗氏有限公司研发出一种用于检测和鉴定临床标本中分枝杆菌的新型试剂盒。该新方法基于通过聚合酶链反应（PCR）扩增临床标本中分枝杆菌的DNA，并采用微孔板杂交法对扩增后的DNA进行杂交，即“罗氏抗酸杆菌扩增检测法（AMP-M）”。日本全国15家结核病医院和机构组织了合作研究，于1993年7月至8月期间收集了349份新入院结核病患者和/或疑似患者的临床标本。所有标本均通过涂片显微镜检查（萋-尼氏染色）、小川鸡蛋培养基培养、改良7H9液体培养基培养以及AMP-M法进行检测。排除因污染、无法在移植的固体培养基上生长等原因未能鉴定出分枝杆菌种类的25份标本后，对324份标本的检测结果进行了分析，其中包括167份既往未治疗病例的标本和157份既往治疗病例的标本。主要结果如下：1. 在既往未治疗病例的70份涂片阳性标本中，小川培养基、7H9培养基培养阳性以及AMP-M法检测阳性的分别有59份（84.3%）、61份（87.1%）和66份（94.3%）。在97份涂片阴性标本中，培养阳性的分别有20份（20.6%）、22份（22.7%）和27份（27.8%）。AMP-M法在两组中的阳性率均最高。2. 假设小川培养基和/或改良7H9培养基培养阳性为“阳性”，计算AMP-M法在既往未治疗病例中的敏感性和特异性。对于既往未治疗病例中的结核分枝杆菌，敏感性为95.8%（68/71），特异性为94.8%（91/96）。对于鸟分枝杆菌和胞内分枝杆菌，尽管观察例数较少，但其敏感性和特异性均为100%。3. 在小川培养基和改良7H9培养基培养均为阴性的96份标本中，有5例出现了所谓的AMP-M法假阳性。然而，这5例经重复AMP-M法检测均为阳性，其中3例后来培养转为阳性，另外两例显示出与结核病相符的临床症状。因此，作者认为AMP-M法在既往未治疗病例中的假阳性率非常低。4. 在86例有既往化疗史的涂片阳性病例中，小川培养基培养阳性、改良7H9培养基培养阳性以及AMP-M法检测阳性的分别有64份（74.4%）、77份（89.5%）和85份（98.8%）。在涂片阴性病例中，培养阳性的分别有71份中的10份（14.1%）、13份（18.3%）和24份（33.8%）。
