...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>BMC Microbiology >A rapid in situ procedure for determination of bacterial susceptibility or resistance to antibiotics that inhibit peptidoglycan biosynthesis
【24h】

A rapid in situ procedure for determination of bacterial susceptibility or resistance to antibiotics that inhibit peptidoglycan biosynthesis

机译：一种快速的原位测定方法，用于测定抑制肽聚糖生物合成的细菌敏感性或耐药性

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Background Antibiotics which inhibit bacterial peptidoglycan biosynthesis are the most widely used in current clinical practice. Nevertheless, resistant strains increase dramatically, with serious economic impact and effects on public health, and are responsible for thousands of deaths each year. Critical clinical situations should benefit from a rapid procedure to evaluate the sensitivity or resistance to antibiotics that act at the cell wall. We have adapted a kit for rapid determination of bacterial DNA fragmentation, to assess cell wall integrity. Results Cells incubated with the antibiotic were embedded in an agarose microgel on a slide, incubated in an adapted lysis buffer, stained with a DNA fluorochrome, SYBR Gold and observed under fluorescence microscopy. The lysis affects the cells differentially, depending on the integrity of the wall. If the bacterium is susceptible to the antibiotic, the weakened cell wall is affected by the lysing solution so the nucleoid of DNA contained inside the bacterium is released and spread. Alternatively, if the bacterium is resistant to the antibiotic, it is practically unaffected by the lysis solution and does not liberate the nucleoid, retaining its normal morphological appearance. In an initial approach, the procedure accurately discriminates susceptible, intermediate and resistant strains of Escherichia coli to amoxicillin/clavulanic acid. When the bacteria came from an exponentially growing liquid culture, the effect on the cell wall of the β-lactam was evident much earlier that when they came from an agar plate. A dose-response experiment with an E. coli strain susceptible to ampicillin demonstrated a weak effect before the MIC dose. The cell wall damage was not homogenous among the different cells, but the level of damage increased as dose increased with a predominant degree of effect for each dose. A microgranular-fibrilar extracellular background was evident in gram-negative susceptible strains after β-lactam treatment. This material was digested by DNase I, hybridised with a specific whole genome probe, and so recognized as DNA fragments released by the bacteria. Finally, 46 clinical strains from eight gram-negative and four gram-positive species were evaluated blind for susceptibility or resistance to one of four different β-lactams and vancomycin, confirming the applicability of the methodology. Conclusion The technique to assess cell wall integrity appears to be a rapid and simple procedure to identify resistant and susceptible strains to antibiotics that interfere with peptidoglycan biosynthesis.
机译：背景技术抑制细菌肽聚糖生物合成的抗生素是当前临床实践中最广泛使用的。然而，抗药性菌株急剧增加，对经济产生严重影响并影响公共卫生，并且每年造成数千例死亡。危急的临床情况应受益于快速的程序，以评估对作用于细胞壁的抗生素的敏感性或耐药性。我们改装了一套用于快速测定细菌DNA片段的试剂盒，以评估细胞壁的完整性。结果将与抗生素孵育的细胞包埋在载玻片上的琼脂糖微凝胶中，在适应的裂解缓冲液中孵育，用DNA荧光染料，SYBR Gold染色并在荧光显微镜下观察。裂解作用会影响细胞，具体取决于壁的完整性。如果细菌对抗生素敏感，则裂解液会影响弱化的细胞壁，从而释放并传播细菌内部所含DNA的核苷酸。可选地，如果细菌对抗生素具有抗性，则其实际上不受裂解液的影响，并且不释放核苷，从而保持其正常的形态学外观。在最初的方法中，该程序可准确区分大肠杆菌对阿莫西林/克拉维酸的敏感，中等和耐药菌株。当细菌来自指数增长的液体培养物时，对β-内酰胺的细胞壁的作用要早于来自琼脂板时的作用。用对氨苄青霉素敏感的大肠杆菌菌株进行的剂量反应实验表明，在MIC剂量之前，这种作用较弱。细胞壁的损伤在不同细胞之间不是均匀的，但是损伤的程度随着剂量的增加而增加，并且每种剂量的作用程度都很高。在β-内酰胺处理后的革兰氏阴性易感菌株中，有明显的微颗粒状纤维状细胞外背景。该物质被DNase I消化，与特定的全基因组探针杂交，因此被细菌识别为DNA片段。最后，对来自8个革兰氏阴性和4个革兰氏阳性物种的46种临床菌株进行了盲法评估，以评估其对四种不同的β-内酰胺和万古霉素之一的敏感性或耐药性，从而证实了该方法的适用性。结论评估细胞壁完整性的技术似乎是鉴定干扰肽聚糖生物合成的抗生素耐药株和敏感株的快速简便的方法。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号