Predation in Homogeneous and Heterogeneous Phage Environments Affects Virulence Determinants of Pseudomonas aeruginosa
Predation in Homogeneous and Heterogeneous Phage Environments Affects Virulence Determinants of Pseudomonas aeruginosa
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DOI：
10.1128/aem.03817-12
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发表时间：
2013-05-01
影响因子：
4.4
通讯作者：
van de Ven, Theo G. M.
中科院分区：
文献类型：
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作者：
Hosseinidoust, Zeinab;Tufenkji, Nathalie;van de Ven, Theo G. M.
在有溶噬体存在的情况下，细菌变异的出现一直是进化研究的基本依据之一。然而，关于噬菌体耐药性获得对细菌适应性和毒力的影响的不同研究结果不一致。我们采用实验进化的方法，在两种不同的同质噬菌体环境和一种异质噬菌体环境下，在选择压力下产生了三种铜绿假单胞菌的变体。与对照相比，变异的适合度和毒力决定因素，如生长、运动、生物膜形成、抗氧化应激以及铁载体和发色团的产生，都发生了显著变化。通过不同噬菌体处理产生的具有相似菌落形态的变异具有不同的表型性状。与某些表型性状相关基因的mRNA转录也发生了显著变化；然而，测序未显示所选基因位点有任何点突变。此外，小菌落变异和黑素变异的出现以及某些变异的pyocyanin和pyoverdin产量的增加被认为会影响种群的毒力。从本研究中获得的知识将从根本上有助于我们理解噬菌体选择压力下细菌的进化动力学，这对于在医学环境中有效利用噬菌体至关重要。
The rise of bacterial variants in the presence of lytic phages has been one of the basic grounds for evolution studies. However, there are incongruent results among different studies investigating the effect of phage resistance acquisition on bacterial fitness and virulence. We used experimental evolution to generate three classes of Pseudomonas aeruginosa variants under selective pressure from two different homogeneous phage environments and one heterogeneous phage environment. The fitness and virulence determinants of the variants, such as growth, motility, biofilm formation, resistance to oxidative stress, and the production of siderophores and chromophores, changed significantly compared to the control. Variants with similar colony morphology that were developed through different phage treatments have different phenotypic traits. Also, mRNA transcription for genes associated with certain phenotypic traits changed significantly; however, sequencing did not reveal any point mutations in selected gene loci. Furthermore, the appearance of small colony variants and melanogenic variants and the increase in pyocyanin and pyoverdin production for some variants are believed to affect the virulence of the population. The knowledge gained from this study will fundamentally contribute to our understanding of the evolutionary dynamics of bacteria under phage selective pressure which is crucial to the efficient utilization of bacteriophages in medical contexts.