Snyder James W, Chaudhry Nadia, Hoffmann Wesley
Department of Pathology and Laboratory Medicine, Section of Clinical Microbiology and Infectious Diseases Molecular Diagnostics, University of Louisville, Louisville, Kentucky, USA.
UofL Healthcare System, Louisville, Kentucky, USA.
J Clin Microbiol. 2024 Dec 11;62(12):e0092224. doi: 10.1128/jcm.00922-24. Epub 2024 Oct 31.
Rapid antimicrobial susceptibility testing (rAST) performed directly from blood cultures is essential to influencing the selection of appropriate antibiotics, preferably targeted therapy, for the treatment of bloodstream infections. Affinity Biosensors has developed the LifeScale, a phenotypic rAST system based on microfluidic sensors with a mechanical resonator that measures the mass of individual microbes. The combination of replication, biomass, and population profiling of individual microbes is analyzed to produce rAST results. The performance of the LifeScale was evaluated and compared to our current standard of care (SOC) antimicrobial susceptibility testing (AST) system under clinical conditions. The results indicated that the LifeScale is easy to use and provides rapid, reliable, and accurate AST results in less than 5 h directly from from positive blood cultures containing Gram-negative organisms listed in the current database. For all organism-antibiotic combinations involving polymicrobial cultures, LifeScale showed a resistant result when either mixed isolate was resistant. If these results prove to be robust on further testing, this may justify the reporting of rapid LifeScale results without the need for additional confirmatory testing.
This is the first clinical-based study of a unique technology using microfluidic sensors to generate rapid antimicrobial susceptibility test results directly from blood cultures containing Gram-negative rods. The issue of polymicrobial cultures was also addressed in this study, which, to our knowledge, has not been addressed in publications of other rapid phenotypic AST systems. Overall, LifeScale results compared favorably with the SOC in terms of overall agreement, especially categorical agreement.
直接从血培养物中进行的快速抗菌药敏试验（rAST）对于影响血流感染治疗中合适抗生素的选择至关重要，最好是靶向治疗。Affinity Biosensors公司开发了LifeScale，这是一种基于微流控传感器的表型rAST系统，带有一个测量单个微生物质量的机械谐振器。通过分析单个微生物的复制、生物量和群体特征来产生rAST结果。在临床条件下对LifeScale的性能进行了评估，并与我们目前的临床标准（SOC）抗菌药敏试验（AST）系统进行了比较。结果表明，LifeScale易于使用，可在不到5小时内直接从含有当前数据库中列出的革兰氏阴性菌的阳性血培养物中提供快速、可靠和准确的AST结果。对于所有涉及多微生物培养的微生物-抗生素组合，当任何一种混合分离株耐药时，LifeScale均显示耐药结果。如果这些结果在进一步测试中得到证实，那么这可能证明无需进行额外的确认性测试即可报告快速的LifeScale结果是合理的。
这是第一项基于临床的研究，采用独特的微流控传感器技术直接从含有革兰氏阴性杆菌的血培养物中生成快速抗菌药敏试验结果。本研究还解决了多微生物培养的问题，据我们所知，其他快速表型AST系统的出版物中尚未涉及这一问题。总体而言，LifeScale的结果在总体一致性方面，尤其是类别一致性方面，与SOC相比具有优势。
