エントロパトジェニックなEscherichia coliの誘導可能な束を形成するピルス
J A Girón1, A S Ho, G K Schoolnik
1Department of Microbiology and Immunology, Beckman Center, Howard Hughes Medical Institute, Stanford University, CA 94305.
まとめ
バンドル形成性ピリ (BFP) は,腸病原性Escherichia coli (EPEC) が小腸に付着し,小児性下痢を引き起こすために不可欠です. 毒性プラズミドにコードされたこれらの piliは,EPECのコロニー化と感染に不可欠です.
科学分野:
- 微生物学 微生物学とは
- パトジェネシス (病原生)
- バクテリアの粘着性
背景:
- エントロパトゲン性Escherichia coli (EPEC) は,小児性下痢の重要な原因である.
- EPECは,上皮細胞に付着したバクテリアコロニーを形成することによって,小腸を植民地化する.
- EPECの毒性における特定の細菌構造の役割は調査中です.
研究 の 目的:
- EPEC粘着性および毒性におけるバンドル形成性ピリ (BFP) の役割を調査する.
- EPECにおけるBFPの表現と組成を特徴づける.
- BFP発現の遺伝的基礎を決定する.
主な方法:
- 固体介質とHEp-2細胞でEPECを培養する.
- BFP発現を評価するためのプラズミド治癒実験.
- 抗血清の製造とEPEC感染に対する検査.
- タンパク質サブユニット分析とアミノ端末配列解析.
主要な成果:
- EPECは,血液アガーまたはHEp-2細胞で育ったとき,BFPと呼ばれるロープのような繊維の束を表現します.
- BFP発現は5つのEPEC血清群で観察され,すべて約92キロ塩基の毒性プラズミドを保持していました.
- プラズミドから治った株は,BFPの発現と粘着的な成長を失いました.
- BFPに対する抗血清は,培養された上皮細胞に感染するEPECの能力を阻害しました.
- BFPサブユニット (19,500ダルトン) は,Vibrio cholerae毒素で調節されたpilin.pilin.にアミノ端末の同質性を示しています.
結論:
- バンドル形成性ピリ (BFP) は,腸病原性Escherichia coli (EPEC) の重要な毒性因子である.
- BFPは,ホストの上皮細胞へのバクテリアの粘着を媒介し,EPECの病原化に貢献します.
- BFPの発現は特定の毒性プラズミドに依存し,その遺伝的基盤を強調しています.
関連する概念動画
Bacterial Gastroenteritis
Bacterial gastroenteritis, characterized by diarrhea, abdominal cramps, and vomiting, is often caused by ingestion of contaminated food or water and is frequently associated with pathogenic Escherichia coli strains. These microbes exploit two principal mechanisms to inflict disease.Shiga toxin–producing E. coli, also referred to as STEC—notably O157:H7—release Shiga toxins that target ribosomes, blocking protein synthesis. The B subunit of the toxin binds the host glycolipid receptor...
Gastritis II: Pathophysiology
The pathophysiology of gastritis begins with the colonization of the stomach lining by Helicobacter pylori (H. pylori). This bacterium spreads mainly via the oral-oral route through saliva or shared utensils, and can also be transmitted in overcrowded or unhygienic environments through contaminated water, despite its brief survival outside the body.ColonizationOnce ingested, H. pylori enters the stomach and begins colonization by navigating through the mucus layer lining the stomach wall. It...
Inflammatory Bowel Disease II: Ulcerative Colitis
Ulcerative colitis is a chronic inflammatory disorder of the colon characterized by continuous mucosal inflammation that typically begins in the rectum and extends proximally in a uniform pattern. Its pathogenesis involves a complex interplay of genetic predisposition, immune dysregulation, and environmental influences. These factors converge to impair the colon’s epithelial defenses and promote an exaggerated inflammatory response against luminal contents.Breakdown of the Mucosal BarrierA...
Inflammatory Bowel Disease III: Crohn's Disease
Crohn’s disease is a chronic, relapsing form of inflammatory bowel disease characterized by segmental, transmural inflammation that can affect any part of the gastrointestinal tract. Its pathogenesis arises from a combination of genetic susceptibility, environmental exposures, epithelial barrier dysfunction, and immune dysregulation. Together, these factors lead to an exaggerated immune response against components of the gut microbiome.Genetic and Environmental InfluencesMultiple genetic...
Diverticular Disease of the Colon
Diverticular disease involves the formation of diverticula—small sac-like outpouchings of the colonic wall—and their complications. It most commonly affects the sigmoid colon due to higher intraluminal pressure and structural vulnerability. It results from structural weakness and increased pressure in the colon, producing pseudodiverticula that may remain silent or progress to inflammation and serious complications.Structure of DiverticulaIn diverticulosis, these outpouchings are...
Appendicitis
Appendicitis is an acute inflammatory condition of the vermiform appendix, most commonly caused by obstruction of its lumen. The appendix is a narrow, blind-ended pouch that extends from the cecum, making it particularly prone to obstruction. Causes include fecaliths, lymphoid hyperplasia (often after viral infections), parasites, tumors, or foreign bodies. This obstruction initiates a cascade of pathological changes.Luminal Obstruction and Early InflammationAfter obstruction, normal mucosal...


