2つの防御システムは,第7のパンデミックビブリオコレラからプラズミッドを排除します
Milena Jaskólska1, David W Adams2, Melanie Blokesch3
1Laboratory of Molecular Microbiology, Global Health Institute, School of Life Sciences, Station 19, EPFL-SV-UPBLO, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
Nature
|April 7, 2022
まとめ
2つの新しいプラズミド防御システム,DdmABCとDdmDEは,パンデミックなVibrio cholerae株で特定されました. これらのシステムは プラズミドを排除し 細菌菌に対して防御し 細菌の進化と 抗生物質耐性の広がりに 影響を及ぼします
科学分野:
- 細菌の遺伝学と進化
- 微生物の病原性
- 移動性遺伝子要素
背景:
- 水平遺伝子転送 (HGT) は,プラズミドやバクテリオファージなどの移動性遺伝子要素を通じて細菌の適応を促します.
- バクテリアは侵入する 移動性遺伝子要素に対して 多様な防御メカニズムを持っています
- 第7回コロラ大流行の原因となったビブリオ・コレラエ・エル・トル菌株は 独特の遺伝子特性を備えています
研究 の 目的:
- パンデミック性ビブリオコレラの プラズミド防御システムを特定し,特徴づけること.
- 防衛システムのメカニズムと標的を調査する
- パンデミックV.コレラの進化と抗生物質耐性の拡散におけるこれらのシステムの役割を理解する.
主な方法:
- ビブリオ・コレラエ・エル・トル菌株の遺伝子解析
- プラズミドとバクテリオファージの挑戦試験
- 防衛システムDdmABCとDdmDEのためのアクション研究のメカニズム
- プラズミドを運ぶ細胞の適性検査
主要な成果:
- 2つの保存されたプラズミド防御システム,DdmABCとDdmDEは,パンデミックV.コレラで特定されました.
- これらのシステムは,小さなマルチコピーのプラズミッドを分解するために協力します.
- DdmABCは,中断性感染 (Abi) を通して細菌菌に対する防御を提供し,IncC多剤耐性プラズミッドを含む大きなプラズミッドを運ぶ細胞にフィットネスコストを課します.
- プラズミドはパンデミックなV.コレラ菌株では希少であり,環境株では豊富である.
結論:
- DdmABCとDdmDEシステムは,プラズミド輸送を制御することによって,パンデミックV.コレラの進化の重要な要因である.
- これらの発見は,パンデミック株におけるプラズミドの低い流行を説明し,抗生物質耐性プラズミドの拡散を理解するための意味を持つ.
- これらの防御システムの相互作用が 流行するV.コレラ菌の系統の成功を形作っています
関連する概念動画
CRISPR and crRNAs
17.6K
Bacteria and archaea are susceptible to viral infections just like eukaryotes; therefore, they have developed a unique adaptive immune system to protect themselves. Clustered regularly interspaced short palindromic repeats and CRISPR-associated proteins (CRISPR-Cas) are present in more than 45% of known bacteria and 90% of known archaea.
The CRISPR-Cas system stores a copy of foreign DNA in the host genome and uses it to identify the foreign DNA upon reinfection. CRISPR-Cas has three different...
The CRISPR-Cas system stores a copy of foreign DNA in the host genome and uses it to identify the foreign DNA upon reinfection. CRISPR-Cas has three different...
17.6K
Defense Against Bacterial Pathogens
1.6K
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...
1.6K
The Antiviral System of Bacteria and Archaea: CRISPR
171
CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats is a adaptive immune system found in bacteria and archaea that protects against viral infections. This system enables prokaryotic cells to identify, remember, and neutralize foreign genetic elements, primarily bacteriophages, by storing fragments of the invader’s DNA as a genetic memory.The CRISPR immune response begins during an initial infection. Cas (CRISPR-associated) proteins play a central role in this...
171
Gram-negative Bacterial Protein Secretion Systems
188
Gram-negative bacteria utilize sophisticated protein secretion systems to transport proteins across their double-membrane envelope into the extracellular environment or host cells. Based on their mechanism of action, these systems are classified into one-step and two-step pathways.One-Step Secretion Systems (Types I, III, IV, and VI)One-step secretion systems bypass the periplasm entirely, forming a continuous channel that spans both the inner and outer membranes:Type I Secretion System (T1SS):...
188
Plasmids
247
Plasmids are extrachromosomal DNA molecules found in bacteria, archaea, and some eukaryotic microbes like yeast. These small, circular DNA structures typically contain fewer than 30 genes, although some may exist linearly. Plasmids vary in their number within a cell, known as copy number. Single-copy plasmids are present in one copy per cell and multi-copy plasmids are present in multiple copies, reaching over 100 copies per cell.Plasmids usually replicate independently of the chromosomal DNA...
247
DNA Bacteriophages
195
Bacteriophages, or phages, are viruses that specifically infect bacteria, utilizing their genetic material to hijack host cellular machinery for replication. DNA bacteriophages employ single-stranded DNA (ssDNA) or double-stranded DNA (dsDNA) genomes. These phages exhibit diverse replication strategies and host interactions, influencing their ecological roles and applications in biotechnology and medicine.ssDNA BacteriophagesssDNA phages, with their small genomes, utilize unique strategies to...
195


