来自可转移等离子体的诺隆耐药性
L Martínez-Martínez1, A Pascual, G A Jacoby
1Department of Clinical Microbiology, School of Medicine, University of Seville, Spain.
Lancet (London, England)
|March 31, 1998
概括
来自Klebsiella pneumoniae的多电阻等离子体可以在细菌之间传递类抗药性. 这种等离子体加速了对重要抗菌剂的耐药性的发展和传播.
科学领域:
- 微生物学 微生物学
- 遗传学 是一个遗传学.
- 抗微生物耐药性 抗微生物耐药性
背景情况:
- 细菌通过目标改变或减少药物积累而发展出类抗药性.
- 在临床隔离物中通过等离子体介导的奇诺隆耐药性仍未得到证实.
- 这项研究研究了通过多抗性等离子体对诺抗性的可转移性.
研究的目的:
- 为了确定多抗性等离子体是否可以在细菌菌株之间传递类抗性.
- 评估等离子体转移对诺抗性水平的影响.
- 调查自发突变在增强等离子体介导的类素耐药性的作用.
主要方法:
- 结合被用来在细菌菌株之间转移耐药性等离子体 (pMG252).
- 阿加罗斯凝电泳可视化了各种宿主中的等离子体.
- 在带有和没有等离子体的大肠杆菌菌株中确定了对西普罗夫洛素和纳利迪克酸产生耐药性的自发突变的频率.
主要成果:
- pMG252等离子体增加了Klebsiella pneumoniae菌株缺乏外膜毛孔的奇诺隆耐药性 (西普洛克萨MIC高达32μg/mL).
- 在带有正常毛孔的菌株中观察到较低的抗性水平,但该等离子体显示出广泛的宿主范围,包括大肠杆菌,其他肠杆菌和Pseudomonas aeruginosa.
- 在含有等离子体的大肠杆菌中,诺隆耐药突变物出现的频率超过100倍,达到更高的最小抑制度 (MIC).
结论:
- 在临床Klebsiella pneumoniae分离物中证实了可转移类和纳利迪克酸的耐药性,这种耐药性是在广域宿主等离子体上发现的.
- 虽然等离子体介导的耐药性在野生型菌株中较低,但自发突变很容易增加耐药性水平.
- 这种等离子体可以显著加快对关键抗菌药物耐药性的出现和传播.
相关概念视频
01:45Antibiotic Selection
Researchers use antibiotic resistance genes to identify bacteria that possess a plasmid containing their gene of interest. Antibiotic resistance naturally occurs when a spontaneous DNA mutation creates changes in bacterial genes that eliminate antibiotic activity. Bacteria can share these new resistance genes with their offspring and other bacteria. The overuse and misuse of antibiotics have created a public health crisis, as resistant and multi-resistant bacteria continue to develop.Antibiotic...
01:28Plasmids
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...
01:19Conjugation
Conjugation is a form of horizontal gene transfer that primarily occurs in bacteria and some archaea, promoting genetic diversity and adaptation. Bacteria can acquire resistance genes through conjugative plasmids, allowing them to survive antibiotic treatments that would otherwise be lethal. This process involves direct contact between cells through specialized structures such as the sex pilus and is mediated by conjugative plasmids, including the F (fertility) factor.Conjugation requires...
01:16Transduction
Among the three main modes of HGT—transformation, conjugation, and transduction—transduction is unique in that it is mediated by bacteriophages, or bacterial viruses.Transduction occurs in two ways. Generalized transduction occurs during the lytic cycle of a bacteriophage infection. In this process, bacteriophages infect bacterial cells, replicate within them, and ultimately cause cell lysis, releasing newly assembled virions. Occasionally, random fragments of the bacterial genome are...
01:30Development 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...
01:28Inhibitors of Bacterial DNA Synthesis
Bacterial pathogens depend on precise and efficient DNA replication to sustain infection. Two type II topoisomerases—DNA gyrase and topoisomerase IV—are critical to this process, as they resolve DNA supercoiling and unlink chromosomes during replication. Fluoroquinolones, synthetic derivatives of quinolones, exploit this mechanism by stabilizing the transient DNA–enzyme cleavage complex, preventing strand religation, and causing lethal double-strand breaks. These antibiotics are selectively...