Molloy S L, Ives R, Hoyt A, Taylor R, Rose J B
Department of Biology, University of Hawaii at Hilo, Hilo, HI, USA.
J Appl Microbiol. 2008 Apr;104(4):998-1007. doi: 10.1111/j.1365-2672.2007.03655.x. Epub 2007 Nov 27.
To evaluate throughput of seeded Legionella pneumophila bacteria in domestic point-of-use filters.
The filters were challenged with tap water seeded with Leg. pneumophila. After multiple challenge events (4.25 x 10(11) CFU per filter), the levels of Legionella were lower in the effluent from the filter containing both copper and silver (mean 4.48 x 10(3) CFU ml(-1)) than in the effluent from the filter containing copper only (1.26 x 10(4) CFU ml(-1); P < 0.001). After a single challenge event of approx. 5 x 10(9) CFU L. pneumophila per filter, there was no significant difference between the levels of Legionella in the effluents from a carbon filter containing copper and a carbon filter with no metals (mean 6.87 x 10(2) and 6.89 x 10(2) CFU ml(-1), respectively; P = 0.985).
Legionella was detected in filter effluent up to 6 weeks after being challenged, indicating that while filters may reduce the levels during an initial contamination event, the exposure is extended as the accumulated bacteria slough off over time.
This study has provided an understanding of the response of Legionella to the use of silver and copper in domestic point-of-use carbon filters.
评估家用终端过滤器中接种嗜肺军团菌的细菌通量。
用接种嗜肺军团菌的自来水对过滤器进行挑战。在多次挑战事件后（每个过滤器4.25×10¹¹CFU），含铜和银的过滤器流出物中的军团菌水平（平均4.48×10³CFU/ml）低于仅含铜的过滤器流出物中的水平（1.26×10⁴CFU/ml；P<0.001）。在每个过滤器约5×10⁹CFU嗜肺军团菌的单次挑战事件后，含铜的碳过滤器和不含金属的碳过滤器流出物中的军团菌水平之间没有显著差异（分别为平均6.87×10²和6.89×10²CFU/ml；P = 0.985）。
在受到挑战后长达6周的时间里，在过滤器流出物中检测到军团菌，这表明虽然过滤器在初始污染事件期间可能会降低水平，但随着时间的推移，积累的细菌脱落，暴露时间会延长。
本研究提供了对军团菌对家用终端碳过滤器中银和铜使用的反应的理解。
