一种可诱导氧化的乳酸脱酶使金黄色葡萄球菌能够抵抗天生的免疫力
Anthony R Richardson1, Stephen J Libby, Ferric C Fang
1Department of Laboratory Medicine, University of Washington, Seattle, WA 98195, USA.
概括
黄金葡萄球菌通过产生乳酸盐来适应免疫防御,这有助于它在有害的氧化 (NO) 中生存. 这种代谢适应对病原体至关重要.
科学领域:
- 微生物学 微生物学
- 传染性疾病 传染性疾病
- 细菌病原体的产生
背景情况:
- 黄金葡萄球菌 (Staphylococcus aureus) 是一个主要的人类病原体,影响全球数十亿人.
- 黄金杆菌逃避宿主天生的免疫力,包括抗菌性氧化 (NO).
- 了解细菌耐药机制是对抗感染的关键.
研究的目的:
- 为了研究S. aureus对化应激的代谢适应.
- 为了确定S. aureus通过哪些机制在暴露于氧化下生存.
- 确定特定酶在S. aureus毒性和NO耐药性中的作用.
主要方法:
- 在化应激下对S. aureus的基因表达的分析.
- 生物化学分析测量酶活性 (L-乳酸脱酶,黄血球蛋白).
- 在相关模型中进行病毒性研究,以评估已识别的途径的作用.
主要成果:
- 黄金菌诱导L-乳酸脱酶 (ldh1) 表达,以应对NO.
- 通过ldhl产生的L-乳酸盐在化应激过程中保持了氧化还原稳态.
- 与相关物种相比,NO诱导性乳酸脱酶活性和NO耐药性是S. aureus的独特特征.
结论:
- 通过L-乳酸盐生产的代谢适应对于S. aureus的毒性至关重要.
- 对NO诱导的L-乳酸脱酶的表达是S. aureus的一个关键的生存机制.
- 这一途径使S. aureus与开始性葡萄球菌区分开来,突出了潜在的治疗点.
相关概念视频
Defense Against Bacterial Pathogens
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...
Clinical Significance of Antibiotic Resistance
Methicillin-resistant Staphylococcus aureus (MRSA) presents a critical public health threat, arising from its capacity to resist β-lactam antibiotics due to acquisition of the mecA gene within the staphylococcal cassette chromosome mec (SCCmec). This gene encodes penicillin-binding protein 2a (PBP2a), which impairs binding efficacy of methicillin and other β-lactams. MRSA has evolved into distinct clonal lineages impacting humans and animals alike, reinforcing its significance within the One...
Mechanism of Antibiotic Resistance in MRSA
Antibiotic resistance in bacteria arises when microorganisms evolve the ability to withstand drugs designed to kill them or inhibit their growth, rendering once-effective treatments useless. This phenomenon, driven by genetic change and selection under antibiotic exposure, poses a profound threat to modern medicine. Mechanisms include drug-inactivating enzymes (e.g., β-lactamases), efflux pumps that eject antibiotics, mutations altering antibiotic targets, decreased drug uptake, and acquisition...
Inducible Operons: lac Operon
The lac operon in Escherichia coli is a model for understanding inducible gene regulation and metabolic flexibility. It integrates local control by lactose and global regulation through catabolite repression, enabling E. coli to preferentially metabolize glucose when available and switch to lactose utilization when glucose is scarce.Structure and Function of the lac OperonThe lac operon contains three structural genes: lacZ (β-galactosidase), lacY (lactose permease), and lacA (thiogalactoside...
Staphylococcal Skin Infections
Staphylococcus aureus is a Gram-positive coccus that resides harmlessly on the skin and mucous membranes of healthy individuals. When the skin barrier is breached, it can shift from a commensal to an opportunistic pathogen. This transition is facilitated by surface adhesins, such as clumping factor B and S. aureus surface protein G (SasG), which bind to structural proteins, including loricrin and cytokeratin, in the damaged epidermis. Protein A, another key factor, binds the Fc region of...
Gene Regulation in Microbial Communities: Quorum Sensing
Quorum sensing is a mechanism of bacterial communication that enables coordinated gene expression in response to changes in population density. This facilitates collective behaviors that enhance survival, resource acquisition, and ecological adaptation. This process relies on small signaling molecules called autoinducers that accumulate as bacterial populations grow. When a critical threshold concentration of autoinducers is reached, bacterial cells collectively modify gene expression,...


