Interferometry to understand beta-lactam heteroresistance

世界卫生组织(WHO)强调，抗生素耐药性是最大的医疗疾病之一 21世纪的挑战。因此，选择有效的抗生素是至关重要的，而根据抗生素的选择 对细菌敏感性的影响可能提供最大的治疗益处。目前的抗生素敏感性 检测无法检测到一种常见的耐药性(存在于超过25%的抗生素-细菌中 组合)称为异抗，其中一小部分细菌细胞是表型 抵抗力强。这些耐药细胞在抗生素存在的情况下迅速扩张，因此可能导致治疗。 失败了。临床微生物学的要求使开发新的药敏试验变得更加复杂 实验室；要被采用，药敏试验必须需要最少的体力劳动，工作稳健，并且 平价--通常与高敏感度不一致的房产。基于这些问题，有广泛的 同意需要一种新的技术方法。 在家长资助中，我们建议开发一种新的药敏测试方法，使用干涉法来测量细菌 人口地形。使用干涉测量法测量地形在抗生素中是没有先例的 药敏试验，在一般生物医学研究中几乎没有优先地位。然而，这在物理学中很常见。 和材料科学，因为它是快速的，不需要染料或污渍，并提供超分辨率测量 对地形的影响。干涉仪既便宜又坚固耐用。在令人振奋的初步结果中，我们已经证明 使用干涉测量法，我们可以在2小时内检测到异质电阻，甚至可以分辨出低水平的 由敏感性产生的异质电阻。 在这项设备补充中，我们申请资金购买另一台干涉仪。在…的过程中 开发了一种基于干涉法的药敏试验，我们在β-内酰胺的生物物理学方面取得了一项发现 异质电阻。与家长基金提出的测量和了解细菌的工作相一致 地形，以及拟议的基于干涉测量的诊断工作，在这里，我们建议调查如何 β-内酰胺耐药细胞的生长取决于耐药细胞的局部浓度。这些实验 必须很长(每次至少需要24小时)，得出结论需要进行许多不同的测试 这些细菌对不同的β-内酰胺类药物有抵抗力，因此需要额外的设备。 这个项目解决了有关稀有抗性细胞的生物物理学的基本问题。此外，作为测试版- 内酰胺类抗生素是使用最多的一类抗生素，本文提出的工作结果也将适用于临床 关联性。

The World Health Organization (WHO) has highlighted antibiotic resistance as one of the greatest medical challenges of the 21st century. Choosing effective antibiotics is therefore critical, and basing antibiotic selection on bacterial susceptibilities potentially offers the greatest therapeutic benefit. Current antibiotic susceptibility tests are unable to detect a common form of resistance (present in more than 25% of antibiotic-bacteria combinations) known as heteroresistance, in which a minor subpopulation of bacterial cells is phenotypically resistant. These resistant cells rapidly expand in the presence of an antibiotic and thus can cause treatment failure. Developing a new susceptibility test is further complicated by the requirements of the clinical microbiology laboratory; to be adopted, a susceptibility test must require minimal manual labor, work robustly, and be inexpensive – properties that are often at odds with high sensitivity. Based on these issues, there is broad agreement that a new technological approach is required. In the parent grant, we proposed to develop a new susceptibility test using interferometry to measure bacterial population topography. The use of interferometry to measure topography has no precedence in antibiotic susceptibility testing, and little precedence in biomedical research in general. However, it is common in physics and materials science as it is rapid, doesn’t require dyes or stains, and provides super-resolution measurements of topography. Interferometers are inexpensive and robust. In exciting preliminary results, we have demonstrated that with interferometry we can detect heteroresistance in 2 hours, and even distinguish low levels of heteroresistance from susceptibility. In this equipment supplement, we are requesting funds to purchase another interferometer. In the process of developing an interferometry-based susceptibility test, we made a discovery about the biophysics of beta-lactam heteroresistance. In line with the parent grant’s proposed work on measuring and understanding bacterial topography, as well as proposed work on interferometry-based diagnostics, here we propose to investigate how the growth of beta-lactam resistant cells depends on the local concentration of resistant cells. These experiments are necessarily long (each takes at least 24 hours) and drawing conclusions will require testing many different strains against different beta-lactams, and thus require additional equipment. This project addresses fundamental questions about the biophysics of rare resistant cells. Further, as beta- lactams are the most used class of antibiotics, the results of the work proposed here will also hold clinical relevance.