Mycoplasma pneumoniae biofilms grown in vitro: traits associated with persistence and cytotoxicity
Mycoplasma pneumoniae biofilms grown in vitro: traits associated with persistence and cytotoxicity
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DOI：
10.1099/mic.0.000928
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发表时间：
2020-07-01
期刊：
影响因子：
2.8
通讯作者：
Balish, Mitchell F.
中科院分区：
文献类型：
--
作者：
Feng, Monica;Schaff, Andrew C.;Balish, Mitchell F.
非典型细菌病原体肺炎支原体是人类社区获得性肺炎的主要病原体；感染通常是顽固性、复发性和对抗生素治疗耐药。这些特征表明了一种促进在宿主中长期定居的机制。在体外环境中，肺炎支原体形成的生物膜是不寻常的，因为运动性在它们的形成和发展中只起到非常有限的作用。鉴于肺炎支原体生物膜的不同寻常的性质，与持久性相关的表型仍然是悬而未决的问题，例如哪些特性可能有利于细菌，同时将宿主损害降至最低。肺炎支原体还会产生几种细胞毒性分子，包括社区获得性呼吸窘迫综合征(CADS)毒素、H_2S和H_2O_2，但它在生长过程中如何部署这些药物尚不清楚。虽然几种破坏生物膜的生化技术都是无效的，但需要超声波来破坏肺炎支原体的生物膜以产生单个细胞进行比较研究，这表明不寻常的物理性质可能与非典型的细胞膜有关。然而，像其他细菌一样，生物膜比分散的细胞更不容易受到抗生素抑制和补体杀伤的影响，随着生物膜的成熟，耐药性会增加。与H_2S和H_2O_2产生相关的CADS毒素水平和酶活性在生物膜形成的早期最高，并随着时间的推移而下降，表明与慢性感染有关的毒力减弱。总而言之，这些发现导致了一个模型，说明肺炎支原体生物膜如何有助于肺炎支原体感染的建立和传播，以及生物膜塔和单个细胞如何参与持久性和慢性病。
The atypical bacterial pathogen Mycoplasma pneumoniae is a leading etiological agent of community-acquired pneumonia in humans; infections are often recalcitrant, recurrent and resistant to antibiotic treatment. These characteristics suggest a mechanism that facilitates long-term colonization in hosts. In an in vitro setting, M. pneumoniae forms biofilms that are unusual in that motility plays no more than a very limited role in their formation and development. Given the unusual nature of M. pneumoniae biofilms, open questions remain concerning phenotypes associated with persistence, such as what properties might favour the bacteria while minimizing host damage. M. pneumoniae also produces several cytotoxic molecules including community-acquired respiratory distress syndrome (CARDS) toxin, H2S and H2O2, but how it deploys these agents during growth is unknown. Whereas several biochemical techniques for biofilm disruption were ineffective, sonication was required for dis-ruption of M. pneumoniae biofilms to generate individual cells for comparative studies, suggesting unusual physical properties likely related to the atypical cell envelope. Nonetheless, like for other bacteria, biofilms were less susceptible to antibiotic inhi-bition and complement killing than dispersed cells, with resistance increasing as the biofilms matured. CARDS toxin levels and enzymatic activities associated with H2S and H2O2 production were highest during early biofilm formation and decreased over time, suggesting attenuation of virulence in connection with chronic infection. Collectively, these findings result in a model of how M. pneumoniae biofilms contribute to both the establishment and propagation of M. pneumoniae infections, and how both biofilm towers and individual cells participate in persistence and chronic disease.