The antimicrobial activity of photodynamic therapy against Streptococcus mutans using different photosensitizers.

J Photochem Photobiol B

Faculty of Pharmacy, Dentistry and Nursing, Federal University of Ceará, Department of Operative Dentistry, Rua Cap. Francisco Pedro, S/N, Rodolfo Teófilo, 60430-170 Fortaleza, CE, Brazil.

Published: January 2012

Unlabelled: Several photosensitizers have been used against oral bacteria without standardization. Singlet oxygen ((1)O(2)) is an aggressive chemical species that can kill cells through apoptosis or necrosis.

Objective: to compare the antimicrobial activity of photodynamic therapy (PDT) with different photosensitizers at the same concentration against Streptococcus mutans. In addition, the (1)O(2) production of each photosensitizer was determined. The photosensitizers (163.5 μM) methylene blue (MB), toluidine blue ortho (TBO) and malachite green (MG) were activated with a light-emitting diode (LED; λ=636 nm), while eosin (EOS), erythrosine (ERI) and rose bengal (RB) were irradiated with a curing light (λ=570 nm). Light sources were operated at 24 J cm(-2). For each photosensitizer, 40 randomized assays (n=10 per condition) were performed under one of the following experimental conditions: no light irradiation or photosensitizer, irradiation only, photosensitizer only or irradiation in the presence of a photosensitizer. After treatment, serial dilutions of S. mutans were seeded onto brain heart infusion agar to determine viability in colony-forming units per milliliter (CFU mL(-1)). Generation of (1)O(2) was analyzed by tryptophan photooxidation, and the decay constant was estimated. Results were analyzed by one-way ANOVA and the Tukey-Kramer test (p<0.05). PDT with irradiation in the presence of the photosensitizers TBO and MG was effective in reducing S. mutans counts by 3 and 1.4 logs, respectively (p<0.01), compared to their respective untreated controls. MB generated 1.3 times more (1)O(2) than TBO, and both produced significantly higher concentrations of singlet oxygen than the other photosensitizers. Since in vitro bulk (1)O(2) production does not indicate that (1)O(2) was generated in the bacterial activity site, the bactericidal action against S. mutans cannot be related to in vitro singlet O(2) generation rate. In vitroS. mutans-experiments demonstrated TBO as the only photosensitizer that effectively reduced 99.9% of these microorganisms.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jphotobiol.2011.10.001DOI Listing

Publication Analysis

Top Keywords

antimicrobial activity
8
activity photodynamic
8
photodynamic therapy
8
streptococcus mutans
8
irradiation photosensitizer
8
photosensitizer irradiation
8
photosensitizer
5
therapy streptococcus
4
photosensitizers
4
mutans photosensitizers
4

Similar Publications

Different fates between extracellular and intracellular antimicrobial resistome in full-scale activated sludge and membrane bioreactor processes.

Water Res

January 2025

Faculty of Geosciences and Civil Engineering, Kanazawa University, Kanazawa 920-1192, Japan; Center for Infectious Disease Education and Research (CiDER), Osaka University, 565-0871, Japan. Electronic address:

Treated effluent of wastewater treatment plants (WWTPs) are major sources of extracellular antimicrobial resistance genes (eARGs) into aquatic environments. This study aimed to clarify the fate and origins of eARGs from influent to treated effluent at a full-scale WWTP. The compositions of eARG and intracellular ARG (iARG) were acquired via shotgun metagenomic sequencing in influent wastewater, activated sludge, and treated effluent of the target WWTP, where identical wastewater was treated by conventional activated sludge (CAS) and membrane bioreactor (MBR) processes.

View Article and Find Full Text PDF

A bi-kinase module sensitizes and potentiates plant immune signaling.

Sci Adv

January 2025

Institut für Biologie und Biotechnologie der Pflanzen, Universität Münster, Münster, Germany.

Systemic signaling is an essential hallmark of multicellular life. Pathogen encounter occurs locally but triggers organ-scale and organismic immune responses. In plants, elicitor perception provokes systemically expanding Ca and HO signals conferring immunity.

View Article and Find Full Text PDF

Tigilanol tiglate (EBC-46) is a selective modulator of protein kinase C (PKC) isoforms that is Food and Drug Administration (FDA) approved for the treatment of mast cell tumors in canines with up to an 88% cure rate. Recently, it has been FDA approved for the treatment of soft tissue sarcomas in humans. The role of EBC-46 and, especially, its analogs in efforts to eradicate HIV, treat neurological and cardiovascular disorders, or enhance antigen density in antigen-targeted chimeric antigen receptor-T cell and chimeric antigen receptor-natural killer cell immunotherapies has not been reported.

View Article and Find Full Text PDF

This study identifies the secondary metabolites from Alternaria alternate and evaluates their ACE-2: Spike RBD (SARS-CoV-2) inhibitory activity confirmed via immunoblotting in human lung microvascular endothelial cells. In addition, their in vitro anti-inflammatory potential was assessed using a cell-based assay in LPS-treated RAW 264.7 macrophage cells.

View Article and Find Full Text PDF

Mx proteins, first identified in mammals, encode potent antiviral activity against a wide range of viruses. Mx proteins arose within the Dynamin superfamily of proteins (DSP), which mediate critical cellular processes, such as endocytosis and mitochondrial, plastid, and peroxisomal dynamics. Despite their crucial role, the evolutionary origins of Mx proteins are poorly understood.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!