Effect of intracellular resuscitation of Legionella pneumophila in Acanthamoeba polyphage cells on the antimicrobial properties of silver and copper
Effect of intracellular resuscitation of Legionella pneumophila in Acanthamoeba polyphage cells on the antimicrobial properties of silver and copper
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DOI：
10.1021/es060412t
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发表时间：
2006-12-01
影响因子：
11.4
通讯作者：
Ohgaki, Shinichiro
中科院分区：
文献类型：
--
作者：
Hwang, Myoung Goo;Katayama, Hiroyuki;Ohgaki, Shinichiro
研究了嗜肺军团菌在饮用水（50 mL，pH7.0，25 ℃）条件下进入活的但不可培养（VBNC）状态的特性以及阿米巴多噬菌体细胞的细胞内复苏。在此基础上，研究了L.与铜绿假单胞菌的情况进行了差异性比较，以确定嗜肺假单胞菌对抗菌银和铜试剂的耐受性。L.的数量。在合成饮用水中培养30天内，可培养状态的嗜肺军团菌的数量迅速减少到检测限以下（5.0 log减少），而L.在同一时期，处于存活状态的嗜肺假单胞菌的浓度变化仅为0.1 log减少，并且水平持续190天;相反，铜绿假单胞菌甚至在饮用水中繁殖，并且持续保持其可培养性和存活力190天。不同的是，E.大肠杆菌在可培养和活状态下同时减少为3.0 log和1.6 log减少。L. VBNC状态的嗜肺菌在与A.在相同的环境中（接种的阿米巴的初始种群被调整为1.0 × 10（5）阿米巴/mL），铜绿假单胞菌也在阿米巴细胞中繁殖。最后，L.共孵育10天后，在1.7 × 10（7）CFU/mL浓度下检测到处于增殖期的嗜肺菌，认为该菌群来源于阿米巴细胞破坏引起的阿米巴内细菌释放。暴露于银和铜的共生相的细菌在30分钟内完全失活（超过7个对数减少），而内共生相的细菌对暴露于相同浓度的银和铜显示出高得多的抗性。L. pneumophila和铜绿假单胞菌; 7天后，多噬菌体细胞在银暴露（0.1 mgAg/L）下存活至5.6 x 10（1）和1.1 x 10（1）CFU/mL的水平，在铜暴露（1.0 mgCu/L）下存活至7.3 x 10（3）和6.1 x 10（4）CFU/mL的水平。
The property of Legionella pneumophila entering into a viable but noncultivable (VBNC) state under drinking water conditions (50 mL, pH 7.0, and 25 degrees C) and the intracellular resuscitation in Acanthamoeba polyphage cells were investigated. Then, the survival profiles of L. pneumophila residing in the planktonic phase and the endosymbiosis phase against antimicrobial silver and copper reagents were differentially compared with the case of Pseudomonas aeruginosa. The number of L. pneumophila in a cultivable state was rapidly reduced to below the detection limit (5.0 log reduction) within 30 days of incubation in synthetic drinking water, while the number of L. pneumophila in a viable state varied in only 0.1 log reduction during the same period, and the levels were sustained constantly for 190 days; in contrast, P. aeruginosa multiplied even in drinking water and continuously maintained its cultivability and viability for 190 days. Distinctively, the numbers of E. coli in both cultivable and viable states were simultaneously diminished as 3.0 log and 1.6 log reduction. The cultivability of L. pneumophila in the VBNC state was recovered and started to multiply after coincubation with A. polyphage in the same environment (initial population of inoculated amoeba was adjusted as 1.0 x 10(5) amoeba/mL), and P. aeruginosa also multiplied in amoeba cells. Finally, the populations of L. pneumophila in the planktonic phase after 10 days coincubation were detected at 1.7 x 10(7)CFU/mL, and this population was considered to have originated from the release of bacteria residing inside amoeba caused by the destruction of amoeba cells. Bacteria in the planktonic phase that were exposed to silver and copper were completely inactivated (more than 7 log reduction) within 30 min, while bacteria in the endosymbiosis phase showed much higher resistance against the exposure to the same concentrations of silver and copper. L. pneumophila and P. aeruginosa in A. polyphage cells survived to levels of 5.6 x 10(1) and 1.1 x 10(1) CFU/mL at the silver exposure (0.1 mgAg/L) and 7.3 x 10(3) and 6.1 x 10(4) CFU/mL at the copper exposure (1.0 mgCu/L), respectively, after 7 days.