Aerosolization of Mycobacterium tuberculosis by Tidal Breathing.
Aerosolization of Mycobacterium tuberculosis by Tidal Breathing.
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DOI：
10.1164/rccm.202110-2378oc
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发表时间：
2022-07-15
影响因子：
24.7
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中科院分区：
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阻断结核病（TB）传播需要更好地了解致病微生物结核分枝杆菌（Mtb）如何以及何时雾化。虽然咳嗽通常被认为是结核分枝杆菌气溶胶的主要来源，最近的证据咳嗽独立结核分枝杆菌释放意味着替代机制的贡献。比较结核病患者在三种不同的呼吸方法（潮气呼吸（TiBr）、FVC和咳嗽）中结核分枝杆菌和总颗粒物的雾化情况。在治疗开始前，将生物气溶胶采样和活细胞荧光显微镜Mtb计数与实时测量38例GeneXpert阳性TB患者的CO2浓度和总颗粒计数相结合。对于所有机动，在五个尺寸类别中检测到的颗粒比例相似，大多数颗粒在0.5-5 μm之间。尽管咳嗽样本中的总颗粒计数是TiBr或FVC的4.8倍，但所有三种方法的Mtb阳性率相似。未观察到总颗粒产生与Mtb计数之间的相关性。相反，对于总Mtb计数，个体之间的变异性大于采样操作之间的变异性。最后，当使用24小时呼吸和咳嗽频率进行建模时，我们的数据表明，在有症状的结核病患者中，TiBr可能占每日雾化结核分枝杆菌的90%以上。假设释放的活结核菌的数量提供了一个可靠的代理患者的传染性，我们的观察意味着，溴化钛和结核菌释放的个体间变异性可能是活动性病例中结核病传播的重要因素。
Interrupting tuberculosis (TB) transmission requires an improved understanding of how and when the causative organism, Mycobacterium tuberculosis (Mtb), is aerosolized. Although cough is commonly assumed to be the dominant source of Mtb aerosols, recent evidence of cough-independent Mtb release implies the contribution of alternative mechanisms. To compare the aerosolization of Mtb bacilli and total particulate matter from patients with TB during three separate respiratory maneuvers: tidal breathing (TiBr), FVC, and cough. Bioaerosol sampling and Mtb enumeration by live-cell, fluorescence microscopy were combined with real-time measurement of CO2 concentration and total particle counts from 38 patients with GeneXpert-positive TB before treatment initiation. For all maneuvers, the proportions of particles detected across five size categories were similar, with most particles falling between 0.5–5 μm. Although total particle counts were 4.8-fold greater in cough samples than either TiBr or FVC, all three maneuvers returned similar rates of positivity for Mtb. No correlation was observed between total particle production and Mtb count. Instead, for total Mtb counts, the variability between individuals was greater than the variability between sampling maneuvers. Finally, when modelled using 24-hour breath and cough frequencies, our data indicate that TiBr might contribute more than 90% of the daily aerosolized Mtb among symptomatic patients with TB. Assuming the number of viable Mtb organisms released offers a reliable proxy of patient infectiousness, our observations imply that TiBr and interindividual variability in Mtb release might be significant contributors to TB transmission among active cases.