Anju V T1, Parasuraman Paramanantham1, Sruthil Lal S B2, Alok Sharan2, Asad Syed3, Needa A Bahkali4, Marzouq H Alsaedi3, Kaviyarasu K5, Siddhardha Busi6. 1. Department of Microbiology, School of Life Sciences, Pondicherry University, Puducherry, 605014, India. 2. Department of Physics, School of Physical, Chemical &, Applied Sciences, Pondicherry University, Puducherry, 605014, India. 3. Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia. 4. Biological Sciences Department, Wagner College, 1 Campus Rd, Staten Island, NY, 10301, USA. 5. UNESCO-UNISA Africa Chair in Nanoscience's/Nanotechnology Laboratories, College of Graduate Studies, University of South Africa (UNISA), Muckleneuk Ridge, P O Box 392, Pretoria, South Africa; Nanosciences African Network (NANOAFNET), Materials Research Group (MRG), iThemba LABS-National Research Foundation (NRF), 1 Old Faure Road, 7129, P O Box 722, Somerset West, Western Cape Province, South Africa. Electronic address: kaviyarasuloyolacollege@gmail.com. 6. Department of Microbiology, School of Life Sciences, Pondicherry University, Puducherry, 605014, India. Electronic address: Siddhardha.busi@gmail.com.
Abstract
BACKGROUND: The emergence of drug-resistant bacterial strains has raised the need to develop alternative treatment modalities to combat infectious diseases. Antimicrobial photodynamic therapy (aPDT) is an alternative to conventional treatment modalities. aPDT integrates a photosensitizer, which, after exposure to light of an appropriate wavelength, leads to the generation of cytotoxic reactive oxygen species (ROS). METHODS: The aim of the present study was to synthesize a toluidine blue/multiwalled carbon nanotube conjugate (TBCNT) for enhanced photoinactivation of Pseudomonas aeruginosa and Staphylococcus aureus. Synthesized TBCNT conjugate was characterized and its antibacterial and antibiofilm activity was determined. RESULTS: During TBCNT synthesis, dye loading, and entrapment efficiency of the CNT were 12.04 ± 0.55% and 48.99 ± 2.33%, respectively. The photo-destruction of planktonic cells of the test bacteria was performed by exposure to a 125 mW red laser with a wavelength of 670 nm (radiant exposure of 58.49 J/cm2) for 3 min. Photoinactivation using TBCNT resulted in a 4.91- and 5.47-log10 reduction in P. aeruginosa and S. aureus, respectively. The mechanism of this aPDT was studied by measuring intracellular ROS generation, protein leakage, and lipid peroxidation in the test bacteria after light irradiation. The antibiofilm activity of TBCNT after light exposure was 69.94% and 75.54% for P. aeruginosa and S. aureus, respectively. Photoinactivation of test bacteria treated with TBCNT reduced cell viability and exopolysaccharide production. Confocal laser-scanning microscopy revealed a significant biofilm inhibition efficacy of the TBCNT conjugate. CONCLUSION: Therefore, TBCNT conjugates may be used for the eradication of P. aeruginosa and S. aureus biofilms.
BACKGROUND: The emergence of drug-resistant bacterial strains has raised the need to develop alternative treatment modalities to combat infectious diseases. Antimicrobial photodynamic therapy (aPDT) is an alternative to conventional treatment modalities. aPDT integrates a photosensitizer, which, after exposure to light of an appropriate wavelength, leads to the generation of cytotoxic reactive oxygen species (ROS). METHODS: The aim of the present study was to synthesize a toluidine blue/multiwalled carbon nanotube conjugate (TBCNT) for enhanced photoinactivation of Pseudomonas aeruginosa and Staphylococcus aureus. Synthesized TBCNT conjugate was characterized and its antibacterial and antibiofilm activity was determined. RESULTS: During TBCNT synthesis, dye loading, and entrapment efficiency of the CNT were 12.04 ± 0.55% and 48.99 ± 2.33%, respectively. The photo-destruction of planktonic cells of the test bacteria was performed by exposure to a 125 mW red laser with a wavelength of 670 nm (radiant exposure of 58.49 J/cm2) for 3 min. Photoinactivation using TBCNT resulted in a 4.91- and 5.47-log10 reduction in P. aeruginosa and S. aureus, respectively. The mechanism of this aPDT was studied by measuring intracellular ROS generation, protein leakage, and lipid peroxidation in the test bacteria after light irradiation. The antibiofilm activity of TBCNT after light exposure was 69.94% and 75.54% for P. aeruginosa and S. aureus, respectively. Photoinactivation of test bacteria treated with TBCNT reduced cell viability and exopolysaccharide production. Confocal laser-scanning microscopy revealed a significant biofilm inhibition efficacy of the TBCNT conjugate. CONCLUSION: Therefore, TBCNT conjugates may be used for the eradication of P. aeruginosa and S. aureus biofilms.
Authors: Prince Clarance; Ben Luvankar; Jerin Sales; Ameer Khusro; Paul Agastian; J-C Tack; Manal M Al Khulaifi; Hind A Al-Shwaiman; Abdallah M Elgorban; Asad Syed; H-J Kim Journal: Saudi J Biol Sci Date: 2019-12-24 Impact factor: 4.219
Authors: Denise Muehler; Christina M Rupp; Sercan Keceli; Christoph Brochhausen; Heiko Siegmund; Tim Maisch; Karl-Anton Hiller; Wolfgang Buchalla; Fabian Cieplik Journal: Front Microbiol Date: 2020-10-30 Impact factor: 5.640