Haake G, Kaesler-Neumann I, Hennig H, Meltzer T H, Jornitz M W
Sartorius Stedim Biotech GmbH.
PDA J Pharm Sci Technol. 2012 Jul-Aug;66(4):346-53. doi: 10.5731/pdajpst.2012.00876.
The ASTM 838-05 standard describes a bacteria challenge test procedure based on Brevundimonas diminuta (ATCC 19146) to verify a 0.2 μm rated sterilizing-grade filter. For process validation procedures a correct identification of the challenge organism is essential. The test strain ATCC 700892 repeatedly used for microbial challenge tests was incorrectly named Hydrogenophaga pseudoflava but is phylogenetically linked to the genus Curvibacter, as shown in Part I of this series. Based on these studies the misconception was consolidated that Hydrogenophaga pseudoflava, a widely isolated microorganism also found in biopharmaceutical production settings, is able to penetrate 0.2 μm rated filters. Here we show that the bacteria challenge test results of the strains Curvibacter sp. ATCC 700892 and Hydrogenophaga pseudoflava ATCC 33668 are different. In previous challenge tests analytical filter membranes were used; these do not represent the process scenarios within the sterilizing filtration in industrial processes. To represent process systems, the study data presented were determined with 10" filter cartridge elements. The strain Hydrogenophaga pseudoflava ATCC 33668 is completely retained by 0.2 μm and 0.1 μm rated filters. Depending on the different 0.2 μm filter material there are different retention rates of the strain Curvibacter sp. ATCC 700892; only the 0.1 μm rated filters showed consistent complete retention. However, up to date the genus Curvibacter seems to be of low relevance within biopharmaceutical production settings.
Bacteria challenge tests are used to determine the retention performance of sterilizing-grade filters. The model organism used for bacteria challenge tests and the verification of a 0.2 μm rated sterilizing-grade filter is Brevundimonas diminuta. In previous studies another proposed, model organism used for challenge tests was incorrectly labelled as Hydrogenophaga pseudoflava. Given the predefined retention characteristics, this mislabelled organism was recommended to be included in bacteria challenge studies. However, the herein presented testing demonstrated that the organism is actually phylogenetically affiliated to the genus Curvibacter and not to the strain Hydrogenophaga pseudoflava ATCC 33668. In this report, we demonstrate that the retention of the strain Hydrogenophaga pseudoflava ATCC 33668 with 0.1 μm and 0.2 μm rated filters is comparable to the retention of Brevundimonas diminuta ATCC 19146.
ASTM 838 - 05标准描述了一种基于缺陷短波单胞菌（ATCC 19146）的细菌挑战测试程序，以验证额定孔径为0.2μm的除菌级过滤器。对于工艺验证程序，正确识别挑战微生物至关重要。在本系列的第一部分中显示，反复用于微生物挑战测试的测试菌株ATCC 700892被错误地命名为嗜氢假黄杆菌，但在系统发育上与弯曲杆菌属相关。基于这些研究，一种误解得以强化，即嗜氢假黄杆菌（一种在生物制药生产环境中也广泛分离出的微生物）能够穿透额定孔径为0.2μm的过滤器。在此我们表明，弯曲杆菌属菌株ATCC 700892和嗜氢假黄杆菌ATCC 33668的细菌挑战测试结果是不同的。在先前的挑战测试中使用的是分析滤膜；这些并不代表工业过程中除菌过滤的工艺场景。为了代表工艺系统，本文呈现的研究数据是用10英寸滤芯元件测定的。嗜氢假黄杆菌ATCC 33668菌株被额定孔径为0.2μm和0.1μm的过滤器完全截留。根据不同的0.2μm过滤材料，弯曲杆菌属菌株ATCC 700892有不同的截留率；只有额定孔径为0.1μm的过滤器显示出一致的完全截留。然而，到目前为止，弯曲杆菌属在生物制药生产环境中的相关性似乎较低。
细菌挑战测试用于确定除菌级过滤器的截留性能。用于细菌挑战测试和验证额定孔径为0.2μm的除菌级过滤器的模式生物是缺陷短波单胞菌。在先前的研究中，另一种提议用于挑战测试的模式生物被错误地标记为嗜氢假黄杆菌。鉴于预定义的截留特性，这种错误标记的生物被推荐纳入细菌挑战研究。然而，本文所呈现的测试表明，该生物实际上在系统发育上隶属于弯曲杆菌属，而不是嗜氢假黄杆菌ATCC 33668菌株。在本报告中，我们表明，额定孔径为0.1μm和0.2μm的过滤器对嗜氢假黄杆菌ATCC 33668菌株的截留情况与对缺陷短波单胞菌ATCC 19146的截留情况相当。
