Rapid determination of antibiotic resistance inE. coliusing dielectrophoresis

Abstract

In recent years, infections due to antibiotic-resistant strains of bacteria such as methillicin-resistant Staphylococcus aureus (MRSA) and ciprofloxacin-resistant Escherichia coli are on the rise, and with them the demand for rapid antibiotic testing is also rising. Conventional tests, such as disc diffusion testing, require a primary sample to be tested in the presence of a number of antibiotics to verify which antibiotics suppress growth, which takes approximately 24h to complete and potentially places the patient at severe risk. In this paper we describe the use of dielectrophoresis as a rapid marker of cell death, by detecting changes in the electrophysiology of the cell caused by the administration of an antibiotic. In contrast to other markers, the electrophysiology of the cell changes rapidly during cell death allowing live cells to be distinguished from dead (or dying) cells without the need for culturing. Using Polymyxin B as an example antibiotic, our studies indicate that significant changes in cell characteristics can be observed as soon as 1 hour after isolating a culture from nutrient broth.

Antibiotic susceptibility test based on the dielectrophoretic behavior of elongated Escherichia coli with cephalexin treatment

“…6,7 Chen et al 2 demonstrated the use of the high surface-to-volume ratio microchannel made by polydimethylsiloxane for bacterial culture and rapid AST. Mann and Mikkelsen 4 made a screen-printed carbon electrode array to detect the antibiotic susceptibility of Escherichia coli ͑E.…”

“…coli͒ based on electrochemical measurement. Chiang et al 5 used the SPR biosensor to examine the drug resistance of bacteria, which were treated with the antibiotics for less than 2 h, by measuring 6 utilized a DEP-wall system to assess the drug resistance for bacteria and found that the significant changes in cell characteristics could be observed after 1 h. The cells or bacteria were discriminated based on their dielectric properties and morphology via the proper medium conductivity and the applied electric field. The dielectric properties and shapes of bacteria, which are drug sensitive, are changed by treating antibiotics; 8 thus, the viability of bacteria can be distinguished.…”

The use of microfluidics and dielectrophoresis for separation, concentration, and identification of bacteria

“…Bacteria has also been separated from other bacteria based on differing genera [61,62,71,72,75,76], species [57], and serotypes [77]. Other researchers have used DEP as a means to separate or identify bacteria according to viability [68,78,79] and antibiotic resistance [80][81][82][83][84]. In some cases, DEP has been used to concentrate bacteria to a specific area for subsequent analysis or identification [60,61,71,[85][86][87].…”

Proposing a high-efficiency dielectrophoretic system for separation of dead and live cells

“…Dielectrophoresis has been utilized for detection, manipulation, separation, and characterization of cells [12][13][14][15], bacteria [16][17][18], virus [19,20], parasites [21,22], DNA molecules [23,24], and cell organelles [25,26].…”