Cheong Bosco, He Changchunzi, Laurenson Ian, Claxton Pauline, Kostrzewa Markus, Drobniewski Francis, Larrouy-Maumus Gerald
Department of Life Sciences, Faculty of Natural Sciences, Centre for Bacterial Resistance Biology, Imperial College London, London, United Kingdom.
Adult Infectious Diseases and Center for Bacterial Resistance Biology, Department of Infectious Diseases, Imperial College London Department of Infectious Disease, London, United Kingdom.
Microbiol Spectr. 2025 Sep 2;13(9):e0035625. doi: 10.1128/spectrum.00356-25. Epub 2025 Jul 22.
Managing tuberculosis cases requires species and drug susceptibility identification, which are limited by the time taken by testing procedures due to slow bacterial growth. Lipid-based matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) is a promising tool for identifying pathogenic mycobacterial species. This study aims to define and use species-specific lipid profiles of members of the complex (MTBC) obtained by MALDI-TOF MS, to directly discriminate from other members of the MTBC, such as , , and bacillus Calmette-Guerin (BCG). Reference strains ( H37Rv, , , and BCG) were grown in Middlebrook 7H11 media (supplemented with 10% oleic acid-albumin-dextrose-catalase growth supplement) and incubated for up to 6 weeks at 37°C to generate the large biomass (~10 bacteria) required for optimization, to assess reproducibility of the assay, and to set the reference lipid database. In clinical use, standard shorter culture periods would be sufficient. A blinded study was then performed using a collection of 46 mycobacterial clinical isolate strains composed of 30 . , 2 . , 9 . BCG, and 5 . and grown under the same conditions. Cultured mycobacteria were heat-inactivated and loaded onto the matrix-assisted laser desorption target, followed by the addition of the matrix. Acquisition of the data was done using the negative ion mode. Using the species-specific glycolipid, sulfolipids, was discriminated within MTBC using the MALDI-TOF process with a sensitivity and specificity of 86.7% (95% confidence interval [CI] 69.3-96.2) and 93.7% (95% CI 69.8-99.8), respectively. Direct detection of within the MTBC based on mycobacterial lipid profiling provides a safe and accurate method, based on the detection of the sulfolipids, as a species-specific lipid biomarker of .IMPORTANCETuberculosis remains a major infectious disease in humans and mammals, but one of the major challenges is to accurately discriminate from the other mycobacterial species belonging to the MTBC. Here we report on a novel assay that can detect directly within the MTBC. This approach is simple and relies on the detection of species-specific lipids by routine MALDI-TOF MS.
管理结核病病例需要进行菌种鉴定和药敏试验，由于细菌生长缓慢，检测程序所需时间限制了这些鉴定。基于脂质的基质辅助激光解吸/电离飞行时间质谱（MALDI-TOF MS）是鉴定致病性分枝杆菌菌种的一种有前景的工具。本研究旨在定义并使用通过MALDI-TOF MS获得的结核分枝杆菌复合群（MTBC）成员的种特异性脂质谱，以直接区分MTBC的其他成员，如牛分枝杆菌、非洲分枝杆菌、堪萨斯分枝杆菌和卡介苗（BCG）。参考菌株（结核分枝杆菌H37Rv、牛分枝杆菌、非洲分枝杆菌和卡介苗）在Middlebrook 7H11培养基（补充10%油酸-白蛋白-葡萄糖-过氧化氢酶生长补充剂）中培养，并在37°C下孵育长达6周，以产生优化所需的大量生物量（约10个细菌），评估检测的可重复性，并建立参考脂质数据库。在临床应用中，标准的较短培养期就足够了。然后进行了一项盲法研究，使用了46株分枝杆菌临床分离菌株，其中包括30株结核分枝杆菌、2株牛分枝杆菌、9株卡介苗和5株其他分枝杆菌，并在相同条件下培养。将培养的分枝杆菌热灭活后加载到基质辅助激光解吸靶上，然后加入基质。使用负离子模式采集数据。使用种特异性糖脂、硫脂，通过MALDI-TOF方法在MTBC内区分结核分枝杆菌，灵敏度和特异性分别为86.7%（95%置信区间[CI]69.3 - 96.2）和93.7%（95% CI 69.8 - 99.8）。基于分枝杆菌脂质谱在MTBC内直接检测结核分枝杆菌提供了一种安全准确的方法，该方法基于硫脂的检测，作为结核分枝杆菌的种特异性脂质生物标志物。
结核病仍然是人类和哺乳动物中的一种主要传染病，但主要挑战之一是准确区分结核分枝杆菌与属于MTBC的其他分枝杆菌菌种。在此，我们报告了一种可以在MTBC内直接检测结核分枝杆菌的新检测方法。这种方法简单，依赖于通过常规MALDI-TOF MS检测种特异性脂质。
