Biophysical separation of Staphylococcus epidermidis strains based on antibiotic resistance

Jones, Paul V.; Huey, Shannon; Davis, Paige E.; McLemore, Ryan; McLaren, A. C.; Hayes, Mark A.

doi:10.1039/c5an00906e

Cited by 40 publications

(74 citation statements)

References 58 publications

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“…In a follow-up study by Hoetges et al 182 , the use of DEP was shown to significantly speed the assessment of drug resistance of E. coli to the antibiotic polymyxin B versus the results obtained based on conventional disk diffusion methods. Jones et al 183 observed lower dielectrophoretic mobility under DC fields within a gradient-based dielectrophoresis device for the gentamicin resistant Staphylococcus epidermidis strain versus the respective susceptible strain. While they attribute this observation to the presence of antibiotic resistance enzymes in the former strain, it is unclear how this influence correlates to the DC DEP mobility.…”

Section: Dep Enhanced Microbial Detection Systemsmentioning

confidence: 99%

Review: Microbial analysis in dielectrophoretic microfluidic systems

Fernandez

Rohani

Farmehini

et al. 2017

Analytica Chimica Acta

114

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Infections caused by various known and emerging pathogenic microorganisms, including antibiotic-resistant strains, are a major threat to global health and well-being. This highlights the urgent need for detection systems for microbial identification, quantification and characterization towards assessing infections, prescribing therapies and understanding the dynamic cellular modifications. Current state-of-the-art microbial detection systems exhibit a trade-off between sensitivity and assay time, which could be alleviated by selective and label-free microbial capture onto the sensor surface from dilute samples. AC electrokinetic methods, such as dielectrophoresis, enable frequency-selective capture of viable microbial cells and spores due to polarization based on their distinguishing size, shape and sub-cellular compositional characteristics, for downstream coupling to various detection modalities. Following elucidation of the polarization mechanisms that distinguish bacterial cells from each other, as well as from mammalian cells, this review compares the microfluidic platforms for dielectrophoretic manipulation of microbials and their coupling to various detection modalities, including immuno-capture, impedance measurement, Raman spectroscopy and nucleic acid amplification methods, as well as for phenotypic assessment of microbial viability and antibiotic susceptibility. Based on the urgent need within point-of-care diagnostics towards reducing assay times and enhancing capture of the target organism, as well as the emerging interest in isolating intact microbials based on their phenotype and subcellular features, we envision widespread adoption of these label-free and selective electrokinetic techniques.

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Section: Dep Enhanced Microbial Detection Systemsmentioning

confidence: 99%

Review: Microbial analysis in dielectrophoretic microfluidic systems

Fernandez

Rohani

Farmehini

et al. 2017

Analytica Chimica Acta

114

View full text Add to dashboard Cite

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“…A wide range of bioparticles can be addressed, including animal cells 1 , organelles 2 , proteins 3, 4 , DNA 5–7 and bacteria. 8–11 …”

Section: Introductionmentioning

confidence: 99%

Refinement of insulator-based dielectrophoresis

Crowther

Hayes

2017

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The ability to separate analytes with increasingly similar properties drives the field of separation science. One way to achieve such separations is using trapping and streaming dielectrophoresis (DEP), which directly exploits the subtle differences in the electrophysical properties of analytes. The non-uniform fields necessary for DEP can be formed using various insulator shapes in microchannels. Current insulator shapes include triangles, diamonds, circles, and rectangles. However, all of these insulators pose problems for trapping, streaming, and sorting (deflection) as the induced fields/gradients are not behaviorally consistent across the lateral dimension. This leads to analytes experiencing different forces depending on their pathline in the microchannel and result in low resolution separations. Based on an iterative process that explored approximately 40 different insulator shapes, a design was chosen that indicated improved particle streamlines, better trapping efficiency, and consistent electrical environments across the lateral dimension. The design was assessed by simulations where the electric field, gradient of the electric field squared, and the ratio of the two were plotted. The improved design includes a unique new multi-length scale element. The multi-length scale structure streamlines the analyte(s) and improves homogeneity in the lateral dimension, while still achieving high gradients necessary for analyte separation using DEP. The design is calculated to keep analytes on the centerline which should improve resolution, and eliminate extraneous trapping zones. Behaviors consistent with the features of the simulations were observed in proof of principle experiments using representative test probes.

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“…The next phase of investigations for improved diagnostic capabilities of PJI needs to focus on molecular methods of pathogen identification that are unaffected by antibiotics or comorbidities. Detection of bacteria using electrophoretic impedance measurement may be one method that holds promise for the future [6,7].…”

Section: How Do We Get There?mentioning

confidence: 99%