alexa Flow cytometric assessment of the postantibiotic effect of methicillin on Staphylococcus aureus.
Genetics & Molecular Biology

Genetics & Molecular Biology

Journal of Molecular Biomarkers & Diagnosis

Author(s): Suller MT, Lloyd D

Abstract Share this page

Abstract The postantibiotic effect (PAE) following a 2-h exposure of Staphylococcus aureus NCTC 6571 to methicillin (5x the MIC) was investigated with fluorescent probes, 5-cyano-2,3-di-4-tolyl tetrazolium chloride (CTC), an indicator of respiratory activity, and the membrane potential-sensitive compound bis-(1,3-dibutylbarbituric acid) trimethine oxonol [DiBAC4(3)]. Counts of the numbers of CFU on solid agar correlated well with information gained from the CTC and DiBAC4(3) fluorescence intensity distributions obtained by flow cytometry and revealed that the postantibiotic effect was 3.1 h. Due to the capacity of flow cytometry to provide information on the heterogeneity of a bacterial population, both fluorescent probes identified the emergence of an active subpopulation 4 h after removal of the methicillin, indicating the recovery of a small percentage of the population. After removal of the methicillin and resuspension of the cells in methicillin-free medium, a further decrease in the respiratory activity and the membrane integrity of the population was observed, although the CFU counts hardly varied, indicating continued antibiotic-induced damage. Also, CTC fluorescence measurements identified numerous subpopulations during the PAE period; this suggests that the PAE is complex, with individual organisms exhibiting various degrees of recovery. Flow cytometry thus provides a rapid and sensitive alternative to traditional techniques that have been used to study PAE, with the added advantage that physiological changes can be detected as they arise.
This article was published in Antimicrob Agents Chemother 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