関連する実験動画
Updated: Jun 9, 2025

08:23
Visualization of Bacterial Resistance using Fluorescent Antibiotic Probes
Published on: March 2, 2020
12.6K
リファキシミン予防は,最後の抗生物質のダプトマイシンに対する耐性を引き起こします
Adrianna M Turner1, Lucy Li1, Ian R Monk1
1Department of Microbiology and Immunology, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia.
Nature
|October 24, 2024
まとめ
抗生物質リファキシミンの使用は,バンコミシン耐性エンテロコッカス・フェシウム (VREfm) 感染に対する最後の手段であるダプトマイシンに対する耐性を意外に引き起こします. バクテリアのRNAポリメラーゼ変異によって引き起こされるこのクロスレジスタンスメカニズムは 抗生物質の有効性を脅かしています
科学分野:
- 微生物学
- 分子生物学
- 感染症
背景:
- ヴァンコミシン耐性エンテロコッカス・フェシウム (VREfm) のような多剤耐性病原菌は,世界的な健康上の重大な脅威となっている.
- ダプトミシンはVREfm感染症の 重要な最後の抗生物質ですが 原因不明の耐性が生じています
研究 の 目的:
- VREfmにおける説明できないダプトマイシン耐性のメカニズムを調査する.
- 関連する抗生物質であるリファキシミンがダプトマイシン耐性菌に 寄与するかどうかを判断する.
主な方法:
- リファキシミン曝露後のバクテリアRNAポリメラーゼにおけるアミノ酸の変化を調査した.
- 新しいオペロン (prdRAB) のアップレギュレーションと細胞膜再構成への影響を分析した.
- ダプトマイシン結合と耐性に対するこれらの変異の影響を評価した.
主要な成果:
- リファキシミンの暴露は細菌のRNAポリメラーゼの変異を誘発し,prdRABオペロンのアップレギュレーションにつながります.
- このオペロンは細胞膜の改造を引き起こし,ダプトマイシン結合を減少させ,交叉抵抗性を与える.
- この耐性を与える突然変異は,VREfm株で世界的に流行しています.
結論:
- 以前は抵抗性のリスクが低いと考えられていたリファキシミンの広範な使用は,ダプトマイシンの臨床効果を損なう可能性があります.
- この予期せぬクロスレジスタンスメカニズムは 現在の抗生物質管理の仮定の欠陥を示しています
- リファキシミンの使用は,特に肝疾患の患者では,最後の手段として抗生物質を保存するために緊急に再評価する必要があります.
関連する概念動画
Development of Antibiotic Resistance
Antibiotic resistance is a major public health concern that arises when bacteria evolve mechanisms to withstand the effects of antibiotic treatments. This resistance can be intrinsic, acquired through genetic mutations, or transferred between bacteria via horizontal gene transfer. The development of antibiotic resistance poses significant challenges in treating bacterial infections and necessitates ongoing research to develop new therapeutic strategies.Intrinsic resistance occurs when bacterial...
Combined Effects of Drugs: Synergism
3.7K
Synergism is a useful mechanism where combining two or more drugs is more effective than each constituent used alone. Such combinations are also called supra-additive interactions. The drugs collectively enhance the final therapeutic effect by acting on different targets. Another advantage is that the low dose of each constituent drug is sufficient to achieve the desired effect. This helps reduce the duration of therapy and lower the adverse effects of these drugs.
Such synergistic combinations...
Such synergistic combinations...
3.7K
Pulmonary Tuberculosis V
170
Medical management of tuberculosis (TB) patients involves a comprehensive approach that includes diagnosis, treatment, and monitoring. The specific strategies can vary depending on the type of tuberculosis (latent or active), the patient's overall health status, and other considerations.
Latent tuberculosis infection occurs when TB bacteria are present in a person's body, but are not causing illness or symptoms. It is not contagious, and preventive treatment is crucial to avoid the...
Latent tuberculosis infection occurs when TB bacteria are present in a person's body, but are not causing illness or symptoms. It is not contagious, and preventive treatment is crucial to avoid the...
170
Treatment Resistant Cancers
3.3K
Cancer is the second leading cause of death in the United States. A cancer cell is genetically unstable and hence can mutate faster. They can also modify their microenvironment and escape immune surveillance. The difficulties in treating cancer are further compounded by the emergence of rapid resistance to anticancer drugs. The most common ways to attain resistance in cancer cells include alteration in drug transport and metabolism, modification of drug target, elevated DNA damage response, or...
3.3K
Desensitization and Tachyphylaxis
1.5K
Tachyphylaxis is described as a rapid decrease in response to a drug after repeated or continuous administration of the same drug dose. It is a phenomenon where the body becomes less responsive to a particular substance or intervention over time, requiring higher doses or stronger interventions to achieve the same effect. It results from adaptive changes in the body's receptors, signaling pathways, or physiological processes that occur in response to prolonged exposure to a stimulus.
1.5K
Drugs Affecting GI Tract Motility: Antimicrobials as Antidiarrheal Agents
109
Acute diarrhea, a common gastrointestinal disturbance, is characterized by the rapid evacuation of fluid stools, leading to an excessive weight in fluid. This condition typically arises from disorders affecting intestinal water and electrolyte transport. It can be triggered by an increased osmotic load within the intestine, excessive secretion of electrolytes and water, mucosal exudation of protein and fluid, or altered intestinal motility. The primary risks of acute diarrhea are dehydration...
109

