Iron availability influences aggregation, biofilm, adhesion and invasion of Pseudomonas aeruginosa and Burkholderia cenocepacia
Iron availability influences aggregation, biofilm, adhesion and invasion of Pseudomonas aeruginosa and Burkholderia cenocepacia
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DOI：
10.1177/039463200501800407
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发表时间：
2005-10-01
影响因子：
3.5
通讯作者：
Valenti, P
中科院分区：
文献类型：
--
作者：
Berlutti, F;Morea, C;Valenti, P
铜绿假单胞菌和新洋葱伯克霍尔德菌是囊性纤维化（CF）患者的主要条件致病菌。在健康人的下呼吸道以及所有粘膜中，含有非常低的游离铁浓度（10（-18）M），而在CF患者的痰铁浓度非常高，显示中值为63 x10（-6）M。催化活性铁的积累通过产生活性氧簇并增加细菌生长和毒力而严重促成肺部疾病中的后续临床并发症。本研究中报告的数据表明，低铁浓度（Fe 3 + 1 μ M）诱导铜绿假单胞菌和B中的自由生活形式和运动性。cenocepacia，而高铁浓度（Fe 3 + 10和100 μ M）刺激聚集和生物膜的形成已经在流体相，从而表明聚集和生物膜的形成是积极的铁调制在这些细菌。此外，不同的形态（自由生活，聚集体和生物膜）显示出不同的粘附和入侵支气管细胞系A549的能力。铜绿假单胞菌PAO 1聚集体，主要是生物膜，表现出最高的粘附效率，而B。新洋葱PV 1的聚集体或生物膜最低。铜绿假单胞菌生物膜的侵入效率显著降低，B的细胞内化显著增加。新洋葱虫生物膜已被报道。因此，铁的可利用性是铜绿假单胞菌和B. cenocepacia通过离开能动的自由生活形式并进入新的生活方式，即生物膜来抵消。这些数据可能有助于解释CF患者痰液中的铁过载，诱导非运动形式，聚集体和生物膜，可能有助于穿透宿主上皮屏障，从而促进这些机会性病原体的感染，定植，持久性和全身性传播。
Pseudomonas aeruginosa and Burkholderia cenocepacia are predominant opportunistic pathogens in cystic fibrosis (CF) patients. In healthy humans the lower respiratory tract as well as all mucosa, contains a very low free iron concentration (10(-18) M), while in CF patients' sputum iron concentration is very high, showing a median value of 63x10(-6) M. Accumulation of catalytic reactive iron heavily contributes to subsequent clinical complications in the lung disorders by the production of reactive oxygen species and increases bacterial growth and virulence. The data reported in this study indicate that low iron concentration (Fe3+ 1 mu M) induced free-living forms and motility both in P. aeruginosa and B. cenocepacia, while high iron concentrations (Fe3+ 10 and 100 mu M) stimulated aggregation and biofilm formation already in the fluid phases, so demonstrating that aggregation and biofilm formation are positively iron-modulated in these bacteria. Moreover, the different morphological forms (free-living, aggregates and biofilm) showed different capabilities of adhering and invading the bronchial cell line A549. P. aeruginosa PAO1 aggregates, and mostly biofilm, exerted the highest adhesion efficiency, while B. cenocepacia PV1 aggregates or biofilm the lowest. A significant reduction in invasion efficiency by P. aeruginosa biofilm and a significant increase in cell internalization by B. cenocepacia biofilm has been reported. Therefore, the iron availability is an important signal to which P. aeruginosa and B. cenocepacia counteract by leaving the motile free-living forms and entering into a new lifestyle, i.e. biofilm. These data could contribute to explain that the iron-overload of the sputum of CF patients, inducing nonmotile forms, aggregates and biofilm, may facilitate penetration of host epithelial barriers contributing to the establishment of infection, colonization, persistence and systemic spread of these opportunistic pathogens.