Email Alert | RSS    帮助

中国防痨杂志 ›› 2018, Vol. 40 ›› Issue (4): 378-383.doi: 10.3969/j.issn.1000-6621.2018.04.007

• 论著 • 上一篇    下一篇

CDG-3荧光探针检测结核分枝杆菌的初步研究

武剑楠,孔成成,霍凤敏,孙照刚()   

  1. 101149 首都医科大学附属北京胸科医院国家结核病临床实验室 北京市结核病胸部肿瘤研究所耐药结核病研究北京市重点实验室
  • 收稿日期:2017-12-29 出版日期:2018-04-10 发布日期:2018-05-14
  • 通信作者: 孙照刚 E-mail:sunzg75@163.com
  • 基金资助:
    北京结核病临床数据和样本资源库建设项目(D131100005313012);北京市医院管理局临床医学发展专项(XMLX201812);首都卫生发展科研专项(2018-2-1042)

Preliminary study of a CDG-3 fluorescent probe for detection of Mycobacterium tuberculosis

Jian-nan WU,Cheng-cheng KONG,Feng-min HUO,Zhao-gang SUN()   

  1. National Clinical Laboratory on Tuberculosis, Beijing Key Laboratory for Drug Resistance Tuberculosis Research, Beijing Chest Hospital, Capital Medical University, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing 101149, China
  • Received:2017-12-29 Online:2018-04-10 Published:2018-05-14
  • Contact: Zhao-gang SUN E-mail:sunzg75@163.com

摘要:

目的 探讨CDG-3荧光探针[β-内酰胺酶(BlaC)特异性绿色荧光探针]用于结核病诊断的潜在可能性。方法 为明确CDG-3荧光探针的特异性,选取结核分枝杆菌(Mycobacterium tuberculosis,MTB)标准株H37Rv,牛和非洲分枝杆菌标准株,35种临床相对常见的不同非结核分枝杆菌(nontuberculous mycobacteria,NTM)标准株和6种呼吸道感染病原菌标准株,与CDG-3荧光探针反应后进行检测;为初步了解CDG-3荧光探针临床应用效果,收集2016年1月至9月于北京胸科医院门诊就诊的200例疑似肺结核患者的痰标本分别进行金胺O荧光染色法、培养法(罗氏固体培养联合MGIT960液体培养,二者只要有一种结果为阳性即认为培养阳性)和CDG-3荧光探针检测,并对检测结果进行分析。结果 以H37Rv为标准,CDG-3荧光探针检测牛和非洲分枝杆菌标准株结果均为阳性。试验的35种NTM标准株中,CDG-3荧光探针检测结果阳性的菌株仅有3株,分别是堪萨斯分枝杆菌、玛尔摩分枝杆菌和草分枝杆菌;其余32株的检测结果为阴性。6种呼吸道感染病原菌中,5种检测结果为阴性,1种(诺卡菌)为阳性。在临床痰标本实验中,CDG-3荧光探针对痰MTB的阳性检出率为53.0%(106/200),高于金胺O荧光染色法(29.5%,59/200)与培养法(35.0%,70/200)的阳性率,差异有统计学意义(χ 2值分别为33.587、21.121,P值均为0.000)。以培养法结果为标准,CDG-3荧光探针检测的敏感度为84.3%(59/70),高于金胺O荧光染色法(70.0%,49/70);特异度为63.8%(83/130),低于金胺O荧光染色法(92.3%,120/130);以临床诊断为标准,CDG-3荧光探针检测的敏感度为64.4%(96/149),高于金胺O荧光染色法(39.6%,59/149)和培养法(44.3%,66/149);特异度为95%(19/20),低于金胺O荧光染色法(100%,20/20),高于培养法(90%,18/20)。 结论 CDG-3荧光探针对MTB的选择性较好,受NTM干扰较小,与呼吸道感染病原菌的反应还需进一步研究;CDG-3荧光探针技术具有快速、简便、检出效率高等优势,但特异度有待进一步提高。

关键词: 分枝杆菌,结核, 分枝杆菌,非典型性, 实验室技术和方法, 临床对照试验, CDG-3荧光探针

Abstract:

Objective To explore the potential use of fluorescent probe CDG-3 (a BlaC-specific green fluorescent probe) in the diagnosis of tuberculosis (TB).Methods To clarify the specificity of CDG-3, it was tested with Mycobacterium tuberculosis (MTB) H37Rv, Mycobacterium bovis, Mycobacterium africanum, standard strains of 35 clinically relatively different nontuberculous mycobacteria (NTM) and six different standard strains of respiratory tract pathogens by microscopic examination. To understand the clinical value of CDG-3, a total of 200 morning sputum specimens of outpatients with suspected pulmonary tuberculosis were collected between January and September 2016 in Beijing Chest Hospital. The specimens were evaluated by smear-microscopy, solid Roche culture, MGIT 960 liquid culture and the CDG-3 probe. Culture results were considered positive as long as either the solid Roche culture or MGIT 960 liquid culture results were positive.Results were analyzed statistically with SPSS 19.0 software.Results Using H37Rv as a standard, results obtained with the CDG-3 fluorescence probe for the detection of standard strains of Mycobacterium bovis and Mycobacterium africanum were all positive. Three of the 35 kinds of NTM standard strains (M.kansassi, M.malmoense and M.phlei) also tested positive, while the other 32 strains gave negative results. CDG-3 gave a positive fluorescence signal with Nocardia, but not with the other five respiratory tract pathogens. Testing sputum specimens using CDG-3 gave a positive rate for MTB of 53.0% (106/200), significantly higher than that for smear-microscopy (29.5%, 59/200) and mycobacterium culture (35.0%, 70/200) (χ 2=33.587,P=0.000;χ 2=21.121,P=0.000). Using culture results as the standard, the sensitivity of the CDG-3 probe (84.3%, 59/70) was higher than that of smear-microscopy (70.0%, 49/70); while its specificity was lower (63.8%, 83/130, compared to 92.3%, 120/130). Relative to clinical diagnosis (149 confirmed TB patients), the sensitivity of the CDG-3 probe (64.4%, 96/149) was higher than that of smear-microscopy (39.6%,59/149) and culture (44.3%,66/149), while the specificity of the CDG-3 probe (95%, 19/20) was lower than that of smear-microscopy (100%, 20/20) but higher than that of culture (90%, 18/20). Conclusion The CDG-3 fluorescent probe offers excellent specificity for MTB over many NTMs. The interaction between CDG-3 and respiratory tract pathogens needs further study. The CDG-3 probe has the advantages of being rapid, simple and giving a high detection efficiency, but its specificity is not so ideal.

Key words: Mycobacterium tuberculosis, Mycobacteria,atypical, Laboratory techniques and procedures, Controlled clinical trial, CDG-3 fluorescent probe