Physicochemical mechanisms of bacterial response in the photodynamic potentiation of antibiotic effects

Author(s)

Soares, Jennifer M. ; Guimaraes, Francisco E. G. ; Yakovlev, Vladislav V. ; Bagnato, Vanderlei S. ; Blanco, Kate C.

• Document type: Journal article
• Source: SCIENTIFIC REPORTS; v. 12, n. 1, p. 11-pg., 2022-12-07.

Abstract

Antibiotic failures in treatments of bacterial infections from resistant strains have been a global health concern, mainly due to the proportions they can reach in the coming years. Making microorganisms susceptible to existing antibiotics is an alternative to solve this problem. This study applies a physicochemical method to the standard treatment for modulating the synergistic response towards circumventing the mechanisms of bacterial resistance. Photodynamic inactivation protocols (curcumina 10 mu M, 10 J/cm(2)) and their cellular behavior in the presence of amoxicillin, erythromycin, and gentamicin antibiotics were analyzed from the dynamics of bacterial interaction of a molecule that produces only toxic effects after the absorption of a specific wavelength of light. In addition to bacterial viability, the interaction of curcumin, antibiotics and bacteria were imaged and chemically analyzed using confocal fluorescence microscopy and Fourier-transform infrared spectroscopy (FTIR). The interaction between therapies depended on the sequential order of application, metabolic activity, and binding of bacterial cell surface biomolecules. The results demonstrated a potentiating effect of the antibiotic with up to to 32-fold reduction in minimum inhibitory concentrations and mean reductions of 7 log CFU/ml by physicochemical action at bacterial level after the photodynamic treatment. The changes observed as a result of bacteria-antibiotic interactions, such as membrane permeabilization and increase in susceptibility, may be a possibility for solving the problem of microbial multidrug resistance. (AU)

• FAPESP's process: 19/12694-3 - Treatment of pharyngotonsillitis with photodynamic action
• Grantee: Kate Cristina Blanco
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 14/50857-8 - National Institute in Basic Optics and Applied to Life Sciences
• Grantee: Vanderlei Salvador Bagnato
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 13/07276-1 - CEPOF - Optics and Photonic Research Center
• Grantee: Vanderlei Salvador Bagnato
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 21/09952-0 - Treatment of pharyngotonsillitis with photodynamic action: investigation of basic mechanisms
• Grantee: Kate Cristina Blanco
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor