1.1 本规程描述了一种直接显微镜计数方法（DMC），用于计数金属加工液中抗酸染色的分枝杆菌种群。它可用于检测分枝杆菌总数的水平，包括可培养和不可培养（可能死亡或垂死）的细菌细胞。本规程适用于所有水基金属加工液（分类 D2881 )。 1.2 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 有关其他安全信息，请参阅 实验室安全:原则与实践，第4版 。 2. 1.3 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 ===意义和用途====== 5.1 分枝杆菌细胞计数密度的测量是确定分枝杆菌与职业健康之间可能关系的重要步骤- 相关过敏反应，例如接触金属加工液气溶胶的人的超敏性肺炎（HP）。众所周知，活分枝杆菌计数低估了分枝杆菌的总水平，因为它没有计算在职业健康问题调查中可能同样重要的不可培养、可能死亡或垂死的人群。本文介绍的直接显微镜计数法（DMC）对抗酸杆菌总数进行了定量评估。它包括使用酸- 快速染色，从其他细菌中选择性地识别分枝杆菌，然后在已知区域对已知体积进行计数或直接显微镜计数。尽管其他微生物，特别是放线菌，也能快速染色，但由于其形态和大小，它们与分枝杆菌不同。非分枝杆菌，耐酸微生物比分枝杆菌大50到100倍。该实践提供了有关分枝杆菌总数（可培养、不可培养、有活力和无活力）的定量信息。 结果定量表示为每毫升金属加工液样品中的分枝杆菌。 5.2 使用抗酸染色技术的DMC方法是一种半定量方法，具有相对较快的周转时间。 5.3 DMC方法也可用于现场调查研究，以表征金属加工液系统在长时间内总分枝杆菌密度的变化。 5.4 DMC方法的灵敏度检测极限取决于MF和检测的样品体积（直接或离心等）。

1.1 This practice describes a direct microscopic counting method (DMC) for the enumeration of the acid-fast stained mycobacteria population in metalworking fluids. It can be used to detect levels of total mycobacteria population, including culturable as well as non-culturable (possibly dead or moribund) bacterial cells. This practice is recommended for all water-based metalworking fluids (Classification D2881 ). 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For additional safety information, see Laboratory Safety: Principle and Practices, 4th Edition . 2 1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 5.1 Measurement of mycobacterial cell count densities is an important step in establishing a possible relationship between mycobacteria and occupational health-related allergic responses, for example, hypersensitivity pneumonitis (HP) in persons exposed to aerosols of metalworking fluids. It is known that the viable mycobacteria count underestimates the total mycobacterial levels by not counting the non-culturable, possibly dead or moribund population that is potentially equally important in the investigation of occupational health-related problems. The direct microscopic counting method (DMC) described here gives a quantitative assessment of the total numbers of acid-fast bacilli. It involves using acid-fast staining to selectively identify mycobacteria from other bacteria, followed by enumeration or direct microscopic counting of a known volume over a known area. Although other microbes—particularly the Actinomycetes—also stain acid-fast, they are differentiated from the mycobacteria because of their morphology and size. Non-mycobacteria, acid-fast microbes are 50 to 100 times larger than mycobacteria. This practice provides quantitative information on the total (culturable and non-culturable viable, and non-viable) mycobacteria populations. The results are expressed quantitatively as mycobacteria per mL of metalworking fluid sample. 5.2 The DMC method using the acid-fast staining technique is a semi-quantitative method with a relatively fast turnaround time. 5.3 The DMC method can also be employed in field survey studies to characterize the changes in total mycobacteria densities of metalworking fluid systems over a long period of time. 5.4 The sensitivity detection limit of the DMC method depends on the MF and the sample volume (direct or centrifuged, etc.) examined.