Faculty of Physics - University of Bucharest

UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS

Guest
2024-11-22 1:57

HOME CONFERENCES SEARCH LOGIN NEW USER IMAGES

Conference: Bucharest University Faculty of Physics 2015 Meeting

Section: Biophysics; Medical Physics

Title:

Testing the susceptibility of bacteria in planktonic and biofilms forms to fenotiazines exposed to a 266 nm laser beam emitted by a Nd:YAG laser

Authors:

Tatiana TOZAR (1,2), A. STOICU (1), V. NASTASA (1), Marcela POPA (3), I. R. ANDREI (1), Mariana C. CHIFIRIUC (3), M. L. PASCU (1,2)

Affiliation:

1) National Institute for Laser, Plasma and Radiation Physics, Magurele, Romania

2) Faculty of Physics, University of Bucharest, Magurele, Romania

3) Faculty of Biology, University of Bucharest, Bucharest, Romania

E-mail

tatiana.alexandru@inflpr.ro

Keywords:

Abstract:

The need of alternatives to synthesize new drugs in order to avoid multiple drug resistance (MDR) acquired by bacteria, requests the development of novel therapy drugs by photo-activation of non-antibiotics, such as Chlorpromazine and Thioridazine. The ability to manipulate light in terms of its wavelength, intensity, and duration allows photochemical events to occur and generates photo-products with antimicrobial activity. Chlorpromazine Hydrochloride (CPZ) and Thioridazine Hydrochloride (TZ) dissolved in ultrapure water, at 2 mg/mL, were irradiated with a 6.5 mJ, 266 nm pulsed laser beam generated by a Nd:YAG laser through fourth harmonic built-up, for time intervals between 1 min and 240 min. The techniques used to analyze the generated photoproducts were Absorption Spectroscopy, Thin Layer Chromatography, Laser Induced Fluorescence, Fourier Transform Infrared Spectroscopy, and Liquid Chromatography - tandem Time of Flight Mass Spectroscopy. The antimicrobial activity of the mixture of photoproducts obtained after irradiation of the sample was evaluated. The solutions were tested against gram-positive and gram-negative bacteria and fungi using two methods for antimicrobial susceptibility and testing: minimum inhibitory concentration and minimum biofilm eradication concentration. The results obtained on bacteria by exposing them to solutions irradiated with UV laser beams, which contain the mixtures of photoproducts, are promising for the enhancement of the efficiency of the treatments, so becoming a prospective area of synthetic chemistry.

Acknowledgement:

Acknowledgements: The authors from NILPRP acknowledge the financial support of the Romanian National Authority for Scientific Research, CNCS-UEFISCDI by project number PN-II-ID-PCE-2011-3-0922. T. Tozar was supported by the project POSDRU/159/1.5/S/137750.