Kearns E A, Magaña S, Lim D V
Division of Cell Biology, Microbiology, and Molecular Biology, Department of Biology, University of South Florida, Tampa, FL 33620-5200, USA.
J Appl Microbiol. 2008 Aug;105(2):432-42. doi: 10.1111/j.1365-2672.2008.03757.x. Epub 2008 Feb 19.
Concentration of pathogens diluted in large volumes of water is necessary for their detection. An automated concentration system placed online in drinking water distribution systems would facilitate detection and mitigate the risk to public health.
A prototype concentrator based on dead-end hollow fibre ultrafiltration was used to concentrate Bacillus atrophaeus spores directly from tap water. Backflush was used to recover accumulated particulates for analysis. In field tests conducted on a water utility distribution system, 3.2 x 10(4)-1.4 x 10(6) CFU ml(-1) (6.1 x 10(6)-3.0 x 10(8) CFU) were recovered from the filter when 2.9 x 10(7)-1.0 x 10(9) CFU were spiked into the system. Per cent recovery ranged from 21% to 68% for flow volumes of 15-21 l. Tests using spore influent levels <10 CFU l(-1) (spike < 1000 CFU) yielded 23-40% recovery for volumes >100 l.
B. atrophaeus spores at levels <10 CFU l(-1) were concentrated directly from tap water using an automated dead-end hollow-fibre ultrafiltration system.
The prototype concentrator represents a critical step towards an autonomous system that could be installed in drinking water distribution lines or other critical water lines to facilitate monitoring. Recovered samples can be analysed using standard or rapid biosensor methods.
稀释在大量水中的病原体浓缩对于其检测是必要的。置于饮用水分配系统中的在线自动浓缩系统将有助于检测并降低对公众健康的风险。
基于死端中空纤维超滤的原型浓缩器用于直接从自来水中浓缩萎缩芽孢杆菌孢子。采用反冲洗回收累积的颗粒用于分析。在对一家自来水公司分配系统进行的现场测试中，当向系统中加入2.9×10⁷ - 1.0×10⁹CFU时，从过滤器中回收了3.2×10⁴ - 1.4×10⁶CFU/ml（6.1×10⁶ - 3.0×10⁸CFU）。对于15 - 21升的流量，回收率在21%至68%之间。使用孢子进水水平<10CFU/l（加标量<1000CFU）进行的测试，对于大于100升的体积，回收率为23 - 40%。
使用自动死端中空纤维超滤系统直接从自来水中浓缩水平<10CFU/l的萎缩芽孢杆菌孢子。
该原型浓缩器朝着可安装在饮用水分配管道或其他关键水管中以方便监测的自主系统迈出了关键一步。回收的样品可使用标准或快速生物传感器方法进行分析。
