Kuil Sacha Daniëlle, Hidad Soemeja, Schneeberger Caroline, Singh Pragya, Rhodes Paul, de Jong Menno Douwe, Visser Caroline Elisabeth
Department of Medical Microbiology, Amsterdam Infection & Immunity Institute, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands.
Specific Diagnostics, San Jose, CA 95134, USA.
Antibiotics (Basel). 2022 May 24;11(6):705. doi: 10.3390/antibiotics11060705.
Bacteria produce volatile organic compounds (VOCs) during growth, which can be detected by colorimetric sensor arrays (CSAs). The SpecifAST system (Specific Diagnostics) employs this technique to enable antibiotic susceptibility testing (AST) directly from blood cultures without prior subculture of isolates. The aim of this study was to compare the SpecifAST AST results and analysis time to the VITEK2 (bioMérieux) system.
In a 12-month single site prospective study, remnants of clinical positive monomicrobial blood cultures were combined with a series of antibiotic concentrations. Volatile emission was monitored at 37 °C via CSAs. Minimal Inhibitory Concentrations (MICs) of seven antimicrobial agents for , and spp. were compared to VITEK2 AST results. MICs were interpreted according to EUCAST clinical breakpoints. Performance was assessed by calculating agreement and discrepancy rates.
In total, 96 positive blood cultures containing , and spp. were tested (269 bug-drug combinations). The categorical agreement of the SpecifAST system compared to the VITEK2 system was 100% and 91% for Gram-negatives and Gram-positives, respectively. Errors among Gram-positives were from coagulase-negative staphylococci. Overall results were available in 3.1 h (±0.9 h) after growth detection without the need for subculture steps.
The AST results based on VOC detection are promising and warrant further evaluation in studies with a larger sample of bacterial species and antimicrobials.
细菌在生长过程中会产生挥发性有机化合物（VOCs），可通过比色传感器阵列（CSAs）进行检测。SpecifAST系统（特定诊断公司）采用这项技术，无需对分离株进行预先传代培养，就能直接从血培养物中进行抗生素敏感性测试（AST）。本研究的目的是将SpecifAST的AST结果和分析时间与VITEK2（生物梅里埃公司）系统进行比较。
在一项为期12个月的单中心前瞻性研究中，将临床阳性单微生物血培养物的残余物与一系列抗生素浓度混合。通过CSAs在37°C监测挥发性物质的释放。将七种抗菌药物对大肠埃希菌、肺炎克雷伯菌和金黄色葡萄球菌的最低抑菌浓度（MICs）与VITEK2的AST结果进行比较。MICs根据欧洲抗菌药物敏感性试验委员会（EUCAST）的临床断点进行解释。通过计算一致性和差异率来评估性能。
总共对96份含有大肠埃希菌、肺炎克雷伯菌和金黄色葡萄球菌的阳性血培养物进行了检测（269种菌-药组合）。与VITEK2系统相比，SpecifAST系统对革兰阴性菌和革兰阳性菌的分类一致性分别为100%和91%。革兰阳性菌中的错误来自凝固酶阴性葡萄球菌。在检测到生长后3.1小时（±0.9小时）即可获得总体结果，无需传代培养步骤。
基于VOC检测的AST结果很有前景，但需要在对更多细菌种类和抗菌药物进行研究时进一步评估。
