Brown G S, Betty R G, Brockmann J E, Lucero D A, Souza C A, Walsh K S, Boucher R M, Tezak M S, Wilson M C, Rudolph T, Lindquist H D A, Martinez K F
Sandia National Laboratories, Albuquerque, NM 87185, USA.
J Appl Microbiol. 2007 Oct;103(4):1074-80. doi: 10.1111/j.1365-2672.2007.03331.x.
To evaluate US Centers for Disease Control and Prevention recommended swab surface sample collection method for recovery efficiency and limit of detection for powdered Bacillus spores from nonporous surfaces.
Stainless steel and painted wallboard surface coupons were seeded with dry aerosolized Bacillus atrophaeus spores and surface concentrations determined. The observed mean rayon swab recovery efficiency from stainless steel was 0.41 with a standard deviation (SD) of +/-0.17 and for painted wallboard was 0.41 with an SD of +/-0.23. Evaluation of a sonication extraction method for the rayon swabs produced a mean extraction efficiency of 0.76 with an SD of +/-0.12. Swab recovery quantitative limits of detection were estimated at 25 colony forming units (CFU) per sample area for both stainless steel and painted wallboard.
The swab sample collection method may be appropriate for small area sampling (10 -25 cm2) with a high agent concentration, but has limited value for large surface areas with a low agent concentration. The results of this study provide information necessary for the interpretation of swab environmental sample collection data, that is, positive swab samples are indicative of high surface concentrations and may imply a potential for exposure, whereas negative swab samples do not assure that organisms are absent from the surfaces sampled and may not assure the absence of the potential for exposure.
It is critical from a public health perspective that the information obtained is accurate and reproducible. The consequence of an inappropriate public health response founded on information gathered using an ineffective or unreliable sample collection method has the potential for undesired social and economic impact.
评估美国疾病控制与预防中心推荐的拭子表面样本采集方法，用于从无孔表面采集粉状芽孢杆菌孢子的回收效率和检测限。
在不锈钢和涂漆墙板表面试片上接种干燥雾化的萎缩芽孢杆菌孢子，并测定表面浓度。从不锈钢表面观察到的人造纤维拭子平均回收效率为0.41，标准差（SD）为±0.17；涂漆墙板表面的平均回收效率为0.41，标准差为±0.23。对人造纤维拭子的超声提取方法进行评估，平均提取效率为0.76，标准差为±0.12。不锈钢和涂漆墙板表面每个样本区域的拭子回收定量检测限估计为25个菌落形成单位（CFU）。
拭子样本采集方法可能适用于高病原体浓度下的小面积采样（10 - 25平方厘米），但对于低病原体浓度的大面积表面采样价值有限。本研究结果为解释拭子环境样本采集数据提供了必要信息，即拭子样本呈阳性表明表面浓度高，可能意味着有接触风险，而拭子样本呈阴性并不能确保采样表面不存在生物体，也不能确保不存在接触风险。
从公共卫生角度来看，所获得的信息准确且可重复至关重要。基于使用无效或不可靠样本采集方法收集的信息做出不适当的公共卫生反应，可能会产生不良的社会和经济影响。
