Antibiotic resistance threatens human health worldwide. Patients infected with antibiotic-resistant bacteria require appropriate antibiotic prescriptions based on a rapid antibiotic susceptibility test (AST). Various rapid AST methods have been developed to replace the conventional AST method, which requires a long testing time. However, in most cases, these methods require a high density of bacterial samples, which leads to an additional incubation or concentration process. In this study, we introduce a rapid AST platform that allows the use of low-density bacterial samples by concentrating bacterial cells and performing AST on a single microfluidic chip. In addition, the outlet-free loading process enables the platform to load the sample and concentrate bacteria into a small field of view for single-cell detection. Using this method, rapid AST determined antibiotic resistance in three hours from a standard strain of 103 colony-forming unit (CFU) per ml bacterial concentration. This technique can be used for the cell-based drug testing of various low-concentration bacterial samples.
The authors gratefully acknowledge the support of the National Research Foundation of Korea (NRF) grant funded by the Korean Government (Grant No. 2022R1C1C1010059) and the support from the new faculty research fund of Ajou University.
