在新兴的emm92型组A中对MLSB表现型表达的调控Streptococcus
Lillie M Powell1, Soo Jeon Choi1, Megan E Grund1
1Department of Microbiology, Immunology, and Cell Biology, West Virginia University School of Medicine, Morgantown, WV, USA.
npj antimicrobials and resistance
|January 22, 2025
概括
侵袭性A型链球菌感染正在上升,与MLSB-耐药性有关. 研究人员发现了 erm(T) 基因的遗传和表达变化,解释了 emm92 隔离物中可诱导和构成性宏类耐药机制.
科学领域:
- 微生物学 微生物学
- 分子生物学分子生物学
- 遗传学 遗传学 是一个
背景情况:
- 在过去的十年里,美国的侵袭性A型链球菌 (iGAS) 感染量翻了一番.
- 这种增加与MLSB (宏化物,林科萨米德,链谱素B) 耐药性上升相关.
- 在脆弱人群中出现了带有 erm(T) 基因的 emm92 型分离物.
研究的目的:
- 在emm92iGAS分离物中研究诱导性 (iMLSB) 和构成性 (cMLSB) MLSB耐药性的分子机制.
- 了解 erm(T) 基因在赋予抗生素耐药性的作用.
主要方法:
- 监管区域的序列分析.
- 定量逆转录PCR (RT-qPCR) 和RNA测序 (RNAseq) 用于测量mRNA水平.
- 对ErmT酶的同质模型.
主要成果:
- 在 erm (T) 调节区域的特定多态性与cMLSB耐药性有关.
- 在iMLSB隔离物中,在暴露于红红素时, erm(T) 表达增加.
- cMLSB分离体显示高的erm(T) 表达,独立于抗生素的存在.
- 抗生素暴露影响了核糖体甲基化水平和细菌生长率.
结论:
- 在 erm(T) 基因的调控区域的遗传变异决定了 emm92 iGAS 中的 MLSB 耐药性表型.
- 了解这些耐药机制对于管理iGAS感染至关重要,特别是在风险人群中.
相关概念视频
01:28Global Regulatory Systems
965
Global regulatory systems in bacteria enable rapid and coordinated responses to environmental changes by integrating sensory inputs with gene expression, ensuring efficient adaptation to fluctuating conditions. Key global regulatory mechanisms include regulons, two-component systems, sigma factors, and secondary messengers.Regulons and Global RegulatorsA regulon is a collection of genes and operons controlled by a common global regulator. These regulators enable bacteria to prioritize resource...
965
01:17Gene Regulation During Sporulation
720
Sporulation is a complex developmental process that allows certain Gram-positive bacteria, such as Bacillus subtilis and Clostridium species, to survive extreme environmental conditions. This process is tightly regulated by a series of signaling cascades and transcriptional controls, ensuring the formation of a highly resistant endospore.Sporulation is triggered by unfavorable conditions, such as nutrient depletion, and is governed by a phosphorelay system. One of the sensor kinases, such as...
720
01:23Stringent Response in E. coli
533
Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs...
533
01:28Regulation of Bacterial Virulence
81
Pathogenic bacteria employ a range of regulatory mechanisms to modulate the expression of virulence genes in response to environmental and host-derived signals. These mechanisms ensure that virulence factors are expressed only under favorable conditions, thereby optimizing infection and survival strategies.Mechanisms of Virulence RegulationKey regulatory strategies include:Two-Component Systems: These consist of a membrane-bound sensor kinase and a cytoplasmic response regulator. Environmental...
81
01:25Mechanism of Antibiotic Resistance in MRSA
251
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...
251
01:25Clinical Significance of Antibiotic Resistance
115
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...
115