Operative Unit of Microbiology, University Hospital Policlinico Sant'Orsola-Malpighi, Bologna, Italy.
J Med Microbiol. 2020 Dec;69(12):1398-1404. doi: 10.1099/jmm.0.001268. Epub 2020 Nov 6.
Rapid identification of the causative agent of sepsis is crucial for patient outcomes.. The Sepsityper sample preparation method enables direct microbial identification of positive blood culture samples via matrix-assisted laser desorption ionization/time-of-flight mass spectrometry (MALDI-TOF MS).. The implementation of the Sepsityper method in the routine practice could represent a fundamental tool to achieve a prompt identification of the causative agent of bloodstream infections, and therefore accelerate the adoption of the proper antibiotic treatment. In this study, the novel rapid workflow of the MALDI Biotypr Sepsityper kit (Bruker Daltonik GmbH, Germany) was evaluated using routine samples from a 2-year period (=6918), and dedicated optimized protocols for the microbial groups that were more difficult to identify were developed. Moreover, the use of the residual bacterial pellet to perform susceptibility testing using different methods (commercial broth microdilution, disc diffusion, gradient diffusion) was investigated. The rapid Sepsityper protocol allowed the identification of 5470/6338 (86.3 %) monomicrobial samples at species level, with very good performance for all of the clinically most significant pathogens (2510/2592 enterobacteria, 631/669 and 223/246 enterococci were identified). , and yeasts were the most troublesome to identify, but the application of specific optimized protocols significantly improved their rate of identification (from 14.7-71.5 %, 47.8-89.7 % and 37.1-89.5 %, respectively). Specificity was 100 % (no identification was made for the false-positive samples). Further, the residual pellet proved to be suitable to investigate susceptibility to antimicrobials, enabling us to simplify the workflow and shorten the time to report. The Rapid Sepsityper workflow proved to be a reliable sample preparation method for identification and susceptibility testing directly from positive blood cultures, providing novel approaches for accelerated diagnostics of bloodstream infections.
快速鉴定脓毒症的病原体对于患者的预后至关重要。Sepsityper 样本制备方法可通过基质辅助激光解吸电离/飞行时间质谱（MALDI-TOF MS）直接对阳性血培养样本进行微生物鉴定。在常规实践中实施 Sepsityper 方法可能是实现快速鉴定血流感染病原体的基本工具，从而加速采用适当的抗生素治疗。在这项研究中，评估了新型 MALDI Biotyper Sepsityper 试剂盒（Bruker Daltonik GmbH，德国）的快速工作流程，使用了为期 2 年（=6918）的常规样本，并针对更难鉴定的微生物群开发了专门的优化方案。此外，还研究了使用不同方法（商业肉汤微量稀释法、药敏纸片扩散法、梯度扩散法）对残留细菌沉淀进行药敏试验的可能性。快速 Sepsityper 方案可鉴定 5470/6338（86.3%）份单一致病菌样本，对所有临床意义重大的病原体均具有良好的性能（2510/2592 肠杆菌、631/669 菌和 223/246 肠球菌均被鉴定）。真菌和酵母菌是最难鉴定的，但应用特定的优化方案可显著提高其鉴定率（分别为 14.7-71.5%、47.8-89.7%和 37.1-89.5%）。特异性为 100%（未对假阳性样本进行鉴定）。此外，残留沉淀可用于研究对抗微生物药物的敏感性，从而使我们能够简化工作流程并缩短报告时间。快速 Sepsityper 工作流程已被证明是一种从阳性血培养物中直接进行鉴定和药敏试验的可靠样本制备方法，为加速血流感染的诊断提供了新方法。
