Saini Divey, Hopkins Gregory W, Chen Ching-Ju, Seay Sarah A, Click Eva M, Lee Sunhee, Hartings Justin M, Frothingham Richard
Duke Human Vaccine Institute, PO Box 103020, Duke University Medical Center, Durham, North Carolina 27710, USA.
J Pharmacol Toxicol Methods. 2011 Mar-Apr;63(2):143-9. doi: 10.1016/j.vascn.2010.09.002. Epub 2010 Sep 16.
Multiple factors influence the viability of aerosolized bacteria. The delivery of aerosols is affected by chamber conditions (humidity, temperature, and pressure) and bioaerosol characteristics (particle number, particle size distribution, and viable aerosol concentration). Measurement of viable aerosol concentration and particle size is essential to optimize viability and lung delivery. The Madison chamber is widely used to expose small animals to infectious aerosols.
A multiplex sampling port was added to the Madison chamber to measure the chamber conditions and bioaerosol characteristics. Aerosols of three pathogens (Bacillus anthracis, Yersinia pestis, and Mycobacterium tuberculosis) were generated under constant conditions and their bioaerosol characteristics were analyzed. Airborne microbes were captured using an impinger or BioSampler. The particle size distribution of airborne microbes was determined using an aerodynamic particle sizer (APS). Viable aerosol concentration, spray factor (viable aerosol concentration/inoculum concentration), and dose presented to the mouse were calculated. Dose retention efficiency and viable aerosol retention rate were calculated from the sampler titers to determine the efficiency of microbe retention in lungs of mice.
B. anthracis, Y. pestis, and M. tuberculosis aerosols were sampled through the port. The count mean aerodynamic sizes were 0.98, 0.77, and 0.78 μm with geometric standard deviations of 1.60, 1.90, and 2.37, and viable aerosol concentrations in the chamber were 211, 57, and 1 colony-forming unit (CFU)/mL, respectively. Based on the aerosol concentrations, the doses presented to mice for the three pathogens were 2.5e5, 2.2e4 and 464 CFU.
Using the multiplex sampling port we determined whether the animals were challenged with an optimum bioaerosol based on dose presented and respirable particle size.
多种因素影响雾化细菌的生存能力。气溶胶的输送受腔室条件（湿度、温度和压力）以及生物气溶胶特性（颗粒数量、粒径分布和存活气溶胶浓度）的影响。测量存活气溶胶浓度和粒径对于优化生存能力和肺部递送至关重要。麦迪逊腔室被广泛用于使小动物暴露于感染性气溶胶中。
在麦迪逊腔室上添加了一个多重采样端口，以测量腔室条件和生物气溶胶特性。在恒定条件下生成三种病原体（炭疽芽孢杆菌、鼠疫耶尔森菌和结核分枝杆菌）的气溶胶，并分析其生物气溶胶特性。使用撞击式采样器或生物采样器捕获空气中的微生物。使用空气动力学粒径分析仪（APS）确定空气中微生物的粒径分布。计算存活气溶胶浓度、喷雾因子（存活气溶胶浓度/接种物浓度）以及给予小鼠的剂量。根据采样器滴度计算剂量保留效率和存活气溶胶保留率，以确定小鼠肺部微生物保留的效率。
通过该端口对炭疽芽孢杆菌、鼠疫耶尔森菌和结核分枝杆菌气溶胶进行了采样。计数平均空气动力学粒径分别为0.98、0.77和0.78μm，几何标准差分别为1.60、1.90和2.37，腔室内的存活气溶胶浓度分别为211、57和1个菌落形成单位（CFU）/mL。根据气溶胶浓度，三种病原体给予小鼠的剂量分别为2.5e5、2.2e4和464 CFU。
使用多重采样端口，我们根据给予的剂量和可吸入粒径确定动物是否受到了最佳生物气溶胶的攻击。
