Rapid Susceptibility Testing of MDR M. tuberculosis- Phase II

耐多药结核分枝杆菌快速药敏试验 - II 期

• 批准号: 7156284
• 负责人: MYRON SASSER
• 金额: $ 39.69万
• 依托单位: MIDI, INC.
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2008-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7156284
• 关键词: antibiotics; culture; hydroxy fatty acid; sputum; tuberculosis

DESCRIPTION (provided by applicant): The long-term objective of this project is the development of a system based on high performance liquid chromatography (HPLC) for rapid and accurate antibiotic susceptibility testing of Mycobacterium tuberculosis (MTB). Susceptible and resistant strains of MTB, exposed to anti-MTB antibiotics, exhibit pronounced differences in mycolic acid content. Initial research will focus on adapting the HPLC-based susceptibility testing to current commercially available growth/susceptibility systems. The MIDI Sherlock(r) Mycobacteria Identification System is an HPLC-based system that has FDA 510(k) clearance for identification of MTB. The MIDI Sherlock software will be modified to allow for automated calculation of ratios of mycolic acid content of MTB strains from "control" or from antibiotic-containing media. Although isoniazid causes 35-40% loss of mycolic acids, in susceptible strains, with as little as 20 minutes exposure to the inhibitor, rifampin, ethambutol and pyrazinamide may require up to 72 h for optimal determination. This is in contrast to the typical 6-9 days required for other automated susceptibility test systems. As the highly specific pattern of mycolic acids of MTB is seen in the analysis, contamination by non-mycobacterial species do not cause false resistance evaluations, thus solving a serious problem in other automated systems. A "mixed culture" algorithm will be evaluated for effectiveness in identifying contamination by non-TB mycobacteria. Initial research will use commercially available media and anti-MTB antibiotics to determine resistance or susceptibility by mycolic acid content analysis. This will facilitate adoption of the mycolic acid test by laboratories having the growth-based systems. Although not crucial to the success of the project, direct-from-sputum analysis for MTB identification and susceptibility testing will also be evaluated.

描述(申请人提供)：该项目的长期目标是开发一种基于高效液相色谱法的系统，用于快速准确地检测结核分枝杆菌(MTB)的抗生素敏感性。接触抗结核分枝杆菌抗生素的结核分枝杆菌敏感株和耐药株在霉菌酸含量上表现出明显的差异。最初的研究将侧重于使基于高效液相的药敏试验适应目前商业上可用的生长/药敏系统。MIDI Sherlock(R)分枝杆菌鉴定系统是一种基于高效液相的系统，已通过FDA 510(K)认证来鉴定结核分枝杆菌。MIDI Sherlock软件将进行修改，以允许自动计算“对照”或含有抗生素的培养液中结核分枝杆菌菌株的真菌酸含量比率。虽然异烟肼会导致35-40%的霉菌酸损失，但在敏感菌株中，只需接触该抑制剂20分钟，利福平、乙胺丁醇和吡津酰胺可能需要长达72小时才能获得最佳检测结果。这与其他自动药敏测试系统通常需要6-9天形成鲜明对比。由于在分析中可以看到结核分枝杆菌真菌酸的高度特异性，非分枝杆菌的污染不会导致错误的耐药性评估，从而解决了其他自动化系统中的一个严重问题。将评估“混合培养”算法在识别非结核分枝杆菌污染方面的有效性。初步研究将使用市场上可获得的培养基和抗结核分枝杆菌抗生素，通过霉菌酸含量分析来确定耐药性或敏感性。这将有助于拥有基于生长的系统的实验室采用霉菌酸测试。虽然对该项目的成功不是至关重要的，但也将对用于结核杆菌鉴定和药敏试验的直接痰分析进行评估。