Piepel G F, Deatherage Kaiser B L, Amidan B G, Sydor M A, Barrett C A, Hutchison J R
Applied Statistics and Computational Sciences, Pacific Northwest National Laboratory, Richland, WA, USA.
Chemical and Biological Signature Science Group, Pacific Northwest National Laboratory, Richland, WA, USA.
J Appl Microbiol. 2016 Jul;121(1):149-62. doi: 10.1111/jam.13128. Epub 2016 May 6.
We sought to evaluate the effects of Bacillus species, low surface concentrations, and surface material on recovery efficiency (RE), false-negative rate (FNR) and limit of detection for recovering Bacillus spores using a validated macrofoam-swab sampling procedure.
The performance of a macrofoam-swab sampling method was evaluated using Bacillus anthracis Sterne (BAS) and Bacillus atrophaeus Nakamura (BG) spores applied at nine low target surface concentrations (2 to 500 CFU per plate or coupon) to positive-control plates and test coupons (25·8064 cm(2) ) of four surface materials (glass, stainless steel, vinyl tile and plastic). The Bacillus species and surface material had statistically significant effects on RE, but surface concentration did not. Mean REs were the lowest for vinyl tile (50·8% with BAS and 40·2% with BG) and the highest for glass (92·8% with BAS and 71·4% with BG). FNR values (which ranged from 0 to 0·833 for BAS and from 0 to 0·806 for BG) increased as surface concentration decreased in the range tested. Surface material also had a statistically significant effect on FNR, with FNR the lowest for glass and highest for vinyl tile. Finally, FNR tended to be higher for BG than for BAS at lower surface concentrations, especially for glass.
Concentration and surface material had significant effects on FNR, with Bacillus species having a small effect. Species and surface material had significant effects on RE, with surface concentration having a nonsignificant effect.
The results provide valuable information on the performance of the macrofoam-swab method for low surface concentrations of Bacillus spores, which can be adapted to assess the likelihood that there is no contamination when all macrofoam-swab samples fail to detect B. anthracis.
我们试图通过一种经过验证的大泡沫拭子采样程序，评估芽孢杆菌种类、低表面浓度和表面材料对芽孢杆菌孢子回收效率（RE）、假阴性率（FNR）和检测限的影响。
使用炭疽芽孢杆菌斯特恩株（BAS）和萎缩芽孢杆菌中村株（BG）的孢子，以九种低目标表面浓度（每平板或试片2至500 CFU）应用于阳性对照平板和四种表面材料（玻璃、不锈钢、乙烯基瓷砖和塑料）的测试试片（25.8064平方厘米），评估大泡沫拭子采样方法的性能。芽孢杆菌种类和表面材料对RE有统计学显著影响，但表面浓度没有。乙烯基瓷砖的平均RE最低（BAS为50.8%，BG为40.2%），玻璃的平均RE最高（BAS为92.8%，BG为71.4%）。在所测试的范围内，随着表面浓度降低，FNR值（BAS为0至0.833，BG为0至0.806）增加。表面材料对FNR也有统计学显著影响，玻璃的FNR最低，乙烯基瓷砖的FNR最高。最后，在较低表面浓度下，BG的FNR往往高于BAS，尤其是对于玻璃。
浓度和表面材料对FNR有显著影响，芽孢杆菌种类的影响较小。种类和表面材料对RE有显著影响，表面浓度的影响不显著。
结果为低表面浓度芽孢杆菌孢子的大泡沫拭子方法的性能提供了有价值的信息，可用于评估当所有大泡沫拭子样本均未检测到炭疽芽孢杆菌时无污染的可能性。
