alexa Rapid assessment of ceftazidime, ciprofloxacin, and gentamicin susceptibility in exponentially-growing E. coli cells by means of flow cytometry.
Genetics & Molecular Biology

Genetics & Molecular Biology

Journal of Molecular Biomarkers & Diagnosis

Author(s): Walberg M, Gaustad P, Steen HB

Abstract Share this page

Abstract Exponentially growing E. coli cells were cultivated in the presence of ceftazidime, ciprofloxacin, and gentamicin in concentrations ranging from 0.5-8 minimal inhibitory concentration (MIC), permeabilized by means of cold shock in EDTA/azide, and stained with the DNA-specific dye combination of ethidium bromide and mithramycin before the fluorescence, light scattering, and cell number were measured flow-cytometrically. In order to evaluate the applicability of the cold-shock procedure, cells were also permeabillized by 70\% ethanol. Permeabilization by cold shock, which eliminates washing of the cells, reduced the preparation time to <5 min. A statistically significant increase in light scattering and fluorescence, i.e., cell size and DNA content, could be detected already after 30 min of ceftazidime and ciprofloxacin exposure, even at sub-MIC concentrations. The results obtained with these drugs with cold-shock permeabilization were similar to those seen with ethanol fixation. For gentamicin-treated cells, however, a majority of the cells lost their fluorescence after cold shock. In gentamicin-treated cells fixed in ethanol, there was no consistent effect on either light scattering or fluorescence; however, we observed a substantial fragmentation and leakage of DNA in such cells. The cell proliferation was completely inhibited within 30 min of gentamicin incubation. For all three drugs, loss of light scattering and DNA were associated with cellular disintegration, i.e., reduced viability. The present results demonstrate that effects of ceftazidime, ciprofloxacin, and gentamicin on E. coli can be detected by flow cytometry within 1 h from the beginning of drug exposure to the completed measurement.
This article was published in Cytometry and referenced in Journal of Molecular Biomarkers & Diagnosis

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

  • 9th International Conference and Expo on Molecular & Cancer Biomarkers
    August 23-24, 2017 Birmingham, UK
  • 2nd International Conference on Medical Imaging and Diagnosis
    London, UK
  • 22nd International Conference on Cancer Drugs and Therapeutics
    Paris, France
  • International Conference on Oncology Nursing and Cancer Care
    Singapore City, Singapore
  • World Summit on Cell Signalling and Cancer Therapy
    Toronto, Canada
  • International Conference on Radiology and Imaging
    New York, USA

Relevant Topics

Peer Reviewed Journals
 
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
 
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

 
© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version
adwords