Influence of Streptococcus pneumoniae Within-Strain Population Diversity on Virulence and Pathogenesis.
Influence of Streptococcus pneumoniae Within-Strain Population Diversity on Virulence and Pathogenesis.
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DOI：
10.1128/spectrum.03103-22
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发表时间：
2023-02-14
影响因子：
3.7
通讯作者：
中科院分区：
文献类型：
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作者：
许多细菌病原体的短生成时间允许在常规培养过程中积累新生突变，用于细菌储备的制备和繁殖。以人类主要病原体肺炎链球菌为例，我们试图确定标准实验室处理微生物对菌株内遗传多样性的影响，并探讨这些变化如何影响毒力特征和实验结果。单次培养过夜的肺炎链球菌D39导致细菌冷冻库中以前罕见的基因型富集，并通过获得突变向细菌群体引入新的变异。对来自不同实验室的D39菌群的比较表明，在个体培养过程中发生的细菌种群结构变化如何累积导致固定的、不同的变化，从而深刻地改变毒力特征。D39通过小鼠感染模型（一种用于标准化毒力的过程），导致D39培养收集库中原本罕见的高适应度基因型（频率<2%）的富集，以及先前优势基因型的丢失。在最显著的例子中，选择携带sdhB突变的频率<2%的基因型与增强的全身毒力有关，sdhB基因被认为是建立肺部感染所必需的。来自相同冷冻砧木的3个单独传代的D39培养物显示出相当大的遗传差异，尽管毒力相当。实验室细菌学涉及高密度培养物的使用，我们通常认为是克隆的，但实际上是由不同丰度的多种基因型组成的群体。我们已经证明，一种广泛使用的肺炎链球菌菌株的单一种群的遗传结构可以通过短期的实验室处理和培养而发生重大改变，并且随着时间的推移，这可能导致毒力特征的变化。我们的研究结果表明，在比较不同实验室使用同一菌株产生的数据时应谨慎，但在比较实验室内随时间的数据时也应谨慎。鉴于近年来下一代测序技术成本的大幅降低，我们提倡对细菌分离物进行频繁的采样和测序。
The short generation time of many bacterial pathogens allows the accumulation of de novo mutations during routine culture procedures used for the preparation and propagation of bacterial stocks. Taking the major human pathogen Streptococcus pneumoniae as an example, we sought to determine the influence of standard laboratory handling of microbes on within-strain genetic diversity and explore how these changes influence virulence characteristics and experimental outcomes. A single culture of S. pneumoniae D39 grown overnight resulted in the enrichment of previously rare genotypes present in bacterial freezer stocks and the introduction of new variation to the bacterial population through the acquisition of mutations. A comparison of D39 stocks from different laboratories demonstrated how changes in bacterial population structure taking place during individual culture events can cumulatively lead to fixed, divergent change that profoundly alters virulence characteristics. The passage of D39 through mouse models of infection, a process used to standardize virulence, resulted in the enrichment of high-fitness genotypes that were originally rare (<2% frequency) in D39 culture collection stocks and the loss of previously dominant genotypes. In the most striking example, the selection of a <2%-frequency genotype carrying a mutation in sdhB, a gene thought to be essential for the establishment of lung infection, was associated with enhanced systemic virulence. Three separately passaged D39 cultures originating from the same frozen stocks showed considerable genetic divergence despite comparable virulence. IMPORTANCE Laboratory bacteriology involves the use of high-density cultures that we often assume to be clonal but that in reality are populations consisting of multiple genotypes at various abundances. We have demonstrated that the genetic structure of a single population of a widely used Streptococcus pneumoniae strain can be substantially altered by even short-term laboratory handling and culture and that, over time, this can lead to changes in virulence characteristics. Our findings suggest that caution should be applied when comparing data generated in different laboratories using the same strain but also when comparing data within laboratories over time. Given the dramatic reductions in the cost of next-generation sequencing technology in recent years, we advocate for the frequent sampling and sequencing of bacterial isolate collections.
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影响因子：
3.9
作者：
Connor TR;Loman NJ;Thompson S;Smith A;Southgate J;Poplawski R;Bull MJ;Richardson E;Ismail M;Thompson SE;Kitchen C;Guest M;Bakke M;Sheppard SK;Pallen MJ
通讯作者：
Pallen MJ
链球菌基因组演化的机理。
影响因子：
3.2
作者：
Andam, Cheryl P.;Hanage, William P.
通讯作者：
Hanage, William P.
影响因子：
10.7
作者：
Green AE;Howarth D;Chaguza C;Echlin H;Langendonk RF;Munro C;Barton TE;Hinton JCD;Bentley SD;Rosch JW;Neill DR
通讯作者：
Neill DR
影响因子：
3.2
作者：
Klockgether, Jens;Munder, Antje;Tuemmler, Burkhard
通讯作者：
Tuemmler, Burkhard
影响因子：
4.2
作者：
Serrano, I.;Melo-Cristino, J.;Ramirez, M.
通讯作者：
Ramirez, M.