Rapid and sensitive detection of gram-negative bacteria using surface-immobilized polymyxin B.
Hyun-Jin KangSang-Hoon LeeHan-Shin KimYong Woo JungHee-Deung ParkPublished in: PloS one (2023)
Although detection of gram-negative bacteria (GNB) in body fluids is important for clinical purpose, traditional gram staining and other recently developed methods have inherent limitations in terms of accuracy, sensitivity, and convenience. To overcome the weakness, this study proposed a method detecting GNB based on specific binding of polymyxin B (PMB) to lipopolysaccharides (LPS) of GNB. Fluorescent microscopy demonstrated that surface immobilized PMB using a silane coupling agent was possible to detect fluorescent signal produced by a single Escherichia coli (a model GNB) cell. Furthermore, the signal was selective enough to differentiate between GNB and gram-positive bacteria. The proposed method could detect three cells per ml within one hour, indicating the method was very sensitive and the sensing was rapid. These results suggest that highly multifold PMB binding on each GNB cell occurred, as millions of LPS are present on cell wall of a GNB cell. Importantly, the principle used in this study was realized in a microfluidic chip for a sample containing E. coli cells suspended in porcine plasma, demonstrating its potential application to practical uses. In conclusion, the proposed method was accurate, sensitive, and convenient for detecting GNB, and could be applied clinically.
Keyphrases
- single cell
- loop mediated isothermal amplification
- escherichia coli
- sensitive detection
- induced apoptosis
- gram negative
- quantum dots
- label free
- cell therapy
- high throughput
- cell wall
- cell cycle arrest
- blood pressure
- stem cells
- multidrug resistant
- ionic liquid
- single molecule
- optical coherence tomography
- bone marrow
- transcription factor
- mesenchymal stem cells
- mass spectrometry
- biofilm formation
- capillary electrophoresis