细菌细胞外囊泡向不同的细菌物种,损害细胞分裂和减少它们的病原性
Yu Kawagishi1, Kazunori Murase1, Anna Grebenshchikova1
1Department of Microbiology, Kyoto University Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan.
概括
大肠杆菌的细胞外囊泡 (EVs) 通过破坏细胞分裂来抑制A组链球菌的生长. 这些细菌EV还减少了毒性和病原性,揭示了新的物种间竞争机制.
科学领域:
- 微生物学 微生物学
- 细菌的传播 细菌的传播
- 跨物种的相互作用 跨物种的相互作用
背景情况:
- 细菌细胞外囊泡 (EVs) 介导通信和宿主相互作用.
- 细菌EVs在物种间相互作用中的作用及其生态意义尚不清楚.
- 研究一种细菌物种的EV如何影响另一种细菌物种对于理解微生物群落至关重要.
研究的目的:
- 阐明埃舍里希亚大肠杆菌EVs抑制A组链球菌 (GAS) 增长的机制.
- 确定大肠杆菌EVs对GAS的生理和生态影响.
- 探索细菌EVs在物种间竞争和毒性调节中的潜力.
主要方法:
- 研究了大肠杆菌EVs与GAS细胞的相互作用.
- 使用显微镜分析了GAS细胞分裂过程,包括隔膜形成和糖体重塑.
- 在对大肠杆菌EVs的反应中进行了GAS的基因表达分析.
- 在小鼠模型中评估了大肠杆菌EVs对GAS病原性的影响.
主要成果:
- 大肠杆菌EVs附着在GAS细胞上,诱导有缺陷的细胞分裂,其特征是多个和Z环形成.
- EVs抑制了糖体的重塑,导致细胞延长和细胞分离失败,最终抑制了生长.
- 大肠杆菌EVs改变了大约10%的GAS基因的表达,影响了复制,分裂和新陈代谢.
- EVs显著降低关键的GAS毒性基因 (例如,slo,nga,hasA) 的调节,并在体内减弱GAS的致病性.
结论:
- 大肠杆菌EV具有跨物种竞争功能,通过诱导细胞分裂缺陷抑制GAS生长.
- 在GAS中EV介导的基因表达变化有助于减少毒性和致病性.
- 这项研究强调了细菌EVs在塑造微生物社区动态和物种间竞争中的重要作用.
相关概念视频
Intracellular Movement of Viruses and Bacteria
2.7K
Intracellular bacteria and viruses often comprise a group of highly infectious pathogens that can cause several diseases. Bacterial pathogens include those belonging to the genus Rickettsia responsible for conditions such as rocky mountain spotted fever and the Mediterranean spotted fever; Chlamydia, a genus responsible for a sexually transmitted disease; Coxiella burnetii, an agent responsible for Q fever. Viral pathogens include vaccinia—a poxvirus, and herpes simplex virus—a...
2.7K
Bacterial Signaling
30.8K
Bacterial signaling can occur within bacteria (intracellular) or between bacteria (intercellular). At times, a group of bacteria behaves like a community. To achieve this, they engage in quorum sensing, the perception of higher cell density that causes changes in gene expression. Quorum sensing involves both extracellular and intracellular signaling. The signaling cascade starts with a molecule called an autoinducer (AI). Individual bacteria produce AIs that move out of the bacterial cell...
30.8K
Defense Against Bacterial Pathogens
1.3K
The human immune system is a complex network of cells, tissues, and organs that work together to defend the body against bacterial infections. It consists of various immune cells, each playing a specific role in the defense mechanism.
Phagocytes
Phagocytes are the frontline soldiers of the immune system. They include neutrophils and macrophages. Neutrophils are the most abundant type of white blood cell and are quickly mobilized to the site of infection. Macrophages are larger cells that patrol...
Phagocytes
Phagocytes are the frontline soldiers of the immune system. They include neutrophils and macrophages. Neutrophils are the most abundant type of white blood cell and are quickly mobilized to the site of infection. Macrophages are larger cells that patrol...
1.3K
Lysogenic Cycle of Bacteriophages
61.5K
In contrast to the lytic cycle, phages infecting bacteria via the lysogenic cycle do not immediately kill their host cell. Instead, they combine their genome with the host genome, allowing the bacteria to replicate the phage DNA along with the bacterial genome. The incorporated copy of the phage genome is called the prophage. Some prophages can re-activate and enter the lytic cycle. This often occurs in response to a perturbation, such as DNA damage, but can also transpire in the absence of...
61.5K
Lytic Cycle of Bacteriophages
69.9K
Bacteriophages, also known as phages, are specialized viruses that infect bacteria. A key characteristic of phages is their distinctive “head-tail” morphology. A phage begins the infection process (i.e., lytic cycle) by attaching to the outside of a bacterial cell. Attachment is accomplished via proteins in the phage tail that bind to specific receptor proteins on the outer surface of the bacterium. The tail injects the phage’s DNA genome into the bacterial cytoplasm. In the...
69.9K
Overview of Exosomes
2.7K
Exosomes are stable, lipid bilayer-enclosed vesicles capable of crossing biological barriers. They can carry a wide range of molecules required for intercellular communication. Once exosomes are released from the cell where they originated, they enter a recipient cell through various pathways such as fusion, receptor-mediated endocytosis, macropinocytosis, and phagocytosis.
Stahl et al. discovered exosomes in 1983, but the exosomes were initially considered waste products released from the...
Stahl et al. discovered exosomes in 1983, but the exosomes were initially considered waste products released from the...
2.7K


