Dielectrophoresis microbial characterization and isolation of Staphylococcus aureus based on optimum crossover frequency

Abstract

Characterization of antibiotic‐resistant bacteria is a significant concern that persists for the rapid classification and analysis of the bacteria. A technology that utilizes the manipulation of antibiotic‐resistant bacteria is key to solving the significant threat of these pathogenic bacteria by rapid characterization profile. Dielectrophoresis (DEP) can differentiate between antibiotic‐resistant and susceptible bacteria based on their physical structure and polarization properties. In this work, the DEP response of two Gram‐positive bacteria, namely, Methicillin‐resistant Staphylococcus aureus (MRSA) and Methicillin‐susceptible S. aureus (MSSA), was investigated and simulated. The DEP characterization was experimentally observed on the bacteria influenced by oxacillin and vancomycin antibiotics. MSSA control without antibiotics has crossover frequencies () from 6 to 8 MHz, whereas MRSA control is from 2 to 3 MHz. The changed when bacteria were exposed to the antibiotic. As for MSSA, the decreased to 3.35 MHz compared to MSSA control without antibiotics, MRSA, increased to 7 MHz when compared to MRSA control. The changes in the DEP response of MSSA and MRSA with and without antibiotics were theoretically proven using MyDEP and COMSOL simulation and experimentally based on the modification to the bacteria cell walls. Thus, the DEP response can be employed as a label‐free detectable method to sense and differentiate between resistant and susceptible strains with different antibiotic profiles. The developed method can be implemented on a single platform to analyze and identify bacteria for rapid, scalable, and accurate characterization.

Design of a Low-Frequency Dielectrophoresis-Based Arc Microfluidic Chip for Multigroup Cell Sorting

“…When Re[K cm ] > 0, the positive dielectrophoretic force drives the particle to the position with the maximum electric field strength, and when Re[K cm ] < 0, the negative dielectrophoretic force drives the particle to the position with the minimum electric field strength. The CM factor can be calculated using Equation (2) for particles of the membrane-free spherical model such as polystyrene microspheres. Cells differ from such particles in that they have a cell membrane, which is a monolayer membrane structure composed of phospholipid bilayers, the cell membrane components differ greatly from those of the cytoplasm, so the influence of the cell membrane cannot be ignored.…”

“…Relying on the versatility of microfluidics in the microscopic field and the low consumables, easy processing, high efficiency and high stability of microfluidic chips, microchip laboratories provide a reliable environment for the study of microscopic substances such as cells and proteins. Microfluidic chips can perform many functions such as the screening of drug-resistant cells [ 1 ], detection of pathogens [ 2 ], focusing of particles or cells [ 3 ], mixing of particles [ 4 ], counting of fluorescent microspheres [ 5 ], immobilization of cells or protein macromolecules [ 6 ], protein detection [ 7 ], screening and isolation of DNA aptamers [ 8 ], etc. The cross-fertilization of microfluidics with other disciplines is the key to achieving many functions.…”