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Item Antimicrobial Photodynamic Therapy Mediated by Fotenticine and Methylene Blue on Planktonic Growth, Biofilms, and Burn Infections of Acinetobacter baumannii(MDPI) Figueiredo-Godoi, Lívia Mara Alves; Garcia, Maíra Terra; Pinto, Juliana Guerra; Ferreira-Strixino, Juliana; Faustino, Eliseu Gabriel; Pedroso, Lara Luise Castro; Junqueira, Juliana CamposAntimicrobial photodynamic therapy (aPDT) is considered a promising alternative strategy to control Acinetobacter baumannii infections. In this study, we evaluated the action of aPDT mediated by a new photosensitizer derivative from chlorin e-6 (Fotoenticine—FTC) on A. baumannii, comparing its effects with methylene blue (MB). For this, aPDT was applied on A. baumannii in planktonic growth, biofilms, and burn infections in Galleria mellonella. The absorption of FTC and MB by bacterial cells was also evaluated using microscopic and spectrophotometric analysis. The results of planktonic cultures showed that aPDT reduced the number of viable cells compared to the non-treated group for the reference and multidrug-resistant A. baumannii strains. These reductions varied from 1.4 to 2 log10 CFU for FTC and from 2 log10 CFU to total inhibition for MB. In biofilms, aPDT with MB reduced 3.9 log10 CFU of A. baumannii, whereas FTC had no effect on the cell counts. In G. mellonella, only MB-mediated aPDT had antimicrobial activity on burn injuries, increasing the larvae survival by 35%. Both photosensitizers were internalized by bacterial cells, but MB showed a higher absorption compared to FTC. In conclusion, MB had greater efficacy than FTC as a photosensitizer in aPDT against A. baumannii.Item Analysis of the biomolecular profile by Fourier transform vibrational spectroscopy (FT-IR) in Acinetobacter baumannii after application of photodynamic therapy with curcumin "in vitro "(Elsevier) Marques, Camila Monteiro Santos; Lyra, Lucas Ferreira; Pinto, Juliana Guerra; Sakane, Kumiko Koibuchi; Ferreira-Strixino, JulianaAcinetobacter baumannii stands out for its antimicrobial resistance and high capacity to cause hospital infections, posing a severe threat to global public health. Thus, there is an urgent need for new therapeutic strategies. This work applied photodynamic therapy (PDT) with curcumin to Acinetobacter baumannii, and bacterial cell viability was assessed. Fourier transform infrared spectroscopy (FT-IR) was used to study changes in biomolecules after PDT application, comparing them with control groups that were only irradiated and only with curcumin photosensitizer. According to the results, there was an increase in the total amount of lipids (~0.3 %), total proteins (~0.6 %), and nuclear material (~8.6 %), with a decrease in carbohydrates (~3.0 %) after the appli- cation of PDT, compared to the control group. In the secondary structure of the proteins, a reduction in α-helix (~3.0 %), disordered structure (~7.0 %), and turns (~5.0 %) was observed, with an increase in β-sheets (~8.8 %). The analysis of biomolecular changes by FT-IR after the application of PDT can contribute to understanding the mechanisms of action of cell death, enabling therapeutic strategies to improve diagnosis and clinical treatment.