For the treatment of bacteremia, early diagnosis and rapid antibiotic susceptibility tests (ASTs) are necessary because survival chances decrease significantly if the proper antibiotic administration is delayed. However, conventional methods require several days from blood collection to AST as it requires three overnight cultures, including blood culture, subculture, and AST culture. Herein, we report a more rapid method of sensing bacterial growth and AST in blood based on a vertical capacitance sensor functionalized with aptamers. Owing to their vertical structure, the influence of blood cells sunk by gravity on capacitance measurements were minimized. Thus, bacterial growth in blood at 100–103 CFU/mL was monitored in real-time by measuring changes in capacitance at f = 10 kHz. Moreover, real-time capacitance measurements at f = 0.5 kHz provided information on biofilm formation induced during blood cultures. Bacterial growth and biofilm formation are inhibited above the minimal inhibitory concentration of antibiotics; therefore, we also demonstrated that vertical capacitance aptasensors could be applied to rapid AST from positive blood cultures without a need for the subculture process.
Bibliographical noteFunding Information:
This work was supported by the Nano-Convergence Foundation funded by the Ministry of Science and ICT and the Ministry of Trade, Industry and Energy (Grant no. R201801311 ), and by Basic Science Research Program through the National Research Foundation of Korea ( NRF ) funded by the Ministry of Science, ICT and Future Planning (Grant nos. 2016R1A2B3011980 , 2016R1A2B4014999 , 2019R1H1A2080077 , and 2019R1H1A2079842 ), and NRF funded by the Korean government ( MEST ) ( 2017R1A2B3006704 and 2019R1A6A1A03032869 ) and Brain Korea 21 PLUS Project for Medical Science.
© 2019 Elsevier B.V.
All Science Journal Classification (ASJC) codes
- Biomedical Engineering