TY - JOUR
T1 - Biophysical differentiation of susceptibility and chemical differences in
T2 - Staphylococcus aureus
AU - Hilton, Shannon Huey
AU - Crowther, Claire V.
AU - McLaren, Alex
AU - Smithers, Jared P.
AU - Hayes, Mark A.
N1 - Funding Information:
The authors acknowledge the support of the National Institutes of Health grants 1R03AI099740-01, 1R03AI111361-01, and 1R21AI130855-01.
Publisher Copyright:
© 2020 The Royal Society of Chemistry.
PY - 2020/4/21
Y1 - 2020/4/21
N2 - Differentiating bacteria strains using biophysical forces has been the focus of recent studies using dielectrophoresis (DEP). The refinement of these studies has created high-resolution separations such that very subtle properties of the cells are enough to induce significant differences in measurable biophysical properties. These high-resolution capabilities build upon the advantages of DEP which include small sample sizes and fast analysis times. Studies focusing on differentiating antimicrobial resistant and susceptible bacteria potentially have significant impact on human health and medical care. A prime example is Staphylococcus aureus, which commonly colonizes adults without ill effects. However, the pathogen is an important cause of infections, including surgical site infections. Treatment of S. aureus infections is generally possible with antimicrobials, but antimicrobial resistance has emerged. Of special importance is resistance to methicillin, an antimicrobial created in response to resistance to penicillin. Here, dielectrophoresis is used to study methicillin-resistant (MRSA) and -susceptible S. aureus (MSSA) strains, both with and without the addition of a fluorescent label. The capture onset potential of fluorescently-labeled MRSA (865 ± 71 V) and thus the ratio of electrokinetic to dielectrophoretic mobility, was found to be higher than that of fluorescently-labeled MSSA (685 ± 61 V). This may be attributable to the PBP2a enzyme present in the MRSA strain and not in the MSSA bacteria. Further, unlabeled MRSA was found to have a capture onset potential of 732 ± 44 V, while unlabeled MSSA was found to have a capture onset potential of 562 ± 59 V. This shows that the fluorescently-labeled bacteria require a higher applied potential, and thus ratio of mobilities, to capture than the unlabeled bacteria.
AB - Differentiating bacteria strains using biophysical forces has been the focus of recent studies using dielectrophoresis (DEP). The refinement of these studies has created high-resolution separations such that very subtle properties of the cells are enough to induce significant differences in measurable biophysical properties. These high-resolution capabilities build upon the advantages of DEP which include small sample sizes and fast analysis times. Studies focusing on differentiating antimicrobial resistant and susceptible bacteria potentially have significant impact on human health and medical care. A prime example is Staphylococcus aureus, which commonly colonizes adults without ill effects. However, the pathogen is an important cause of infections, including surgical site infections. Treatment of S. aureus infections is generally possible with antimicrobials, but antimicrobial resistance has emerged. Of special importance is resistance to methicillin, an antimicrobial created in response to resistance to penicillin. Here, dielectrophoresis is used to study methicillin-resistant (MRSA) and -susceptible S. aureus (MSSA) strains, both with and without the addition of a fluorescent label. The capture onset potential of fluorescently-labeled MRSA (865 ± 71 V) and thus the ratio of electrokinetic to dielectrophoretic mobility, was found to be higher than that of fluorescently-labeled MSSA (685 ± 61 V). This may be attributable to the PBP2a enzyme present in the MRSA strain and not in the MSSA bacteria. Further, unlabeled MRSA was found to have a capture onset potential of 732 ± 44 V, while unlabeled MSSA was found to have a capture onset potential of 562 ± 59 V. This shows that the fluorescently-labeled bacteria require a higher applied potential, and thus ratio of mobilities, to capture than the unlabeled bacteria.
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U2 - 10.1039/c9an01449g
DO - 10.1039/c9an01449g
M3 - Article
C2 - 32072998
AN - SCOPUS:85083485183
SN - 0003-2654
VL - 145
SP - 2904
EP - 2914
JO - Analyst
JF - Analyst
IS - 8
ER -