Objective: To investigate the antimicrobial activity of a novel commensal strain of Streptococcus salivarius, LAB813, against Streptococcus mutans biofilms.
Methods: The inhibitory activity of LAB813 towards S. mutans was tested using mono-, dual-, and multi-species cariogenic biofilms formed on three types of orthodontic appliances (metal, ceramic, aligner). The activity of the commercially available probiotic, BLIS M18™ was used as control.
Results: LAB813 significantly inhibited S. mutans biofilms with cell killing approximating 99% for all materials. LAB813 showed effectiveness at inhibiting S. mutans in more complex multi-species biofilms with cell killing approximating 90% for all three materials. When comparing the killing kinetics of the probiotics, LAB813 had a faster rate of killing biofilms than M18. Experiments conducted with cell-free culture supernatant confirmed the presence of an inhibitory substance of proteinaceous nature. The addition of xylitol, a common sugar substitute used for human consumption, potentiated the inhibitory effects of LAB813 against S. mutans embedded in a more complex fungal-bacterial biofilm.
Conclusions: LAB813 possesses strong antimicrobial activity, potent anti-biofilm properties, and enhanced antimicrobial activity in the presence of xylitol. The identification and characterization of strain LAB813 exhibiting antimicrobial activity towards S. mutans hold exciting promise for this novel strain to be developed as an oral probiotic for use in the prevention of dental caries.
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http://dx.doi.org/10.1016/j.archoralbio.2023.105760 | DOI Listing |
Proc Natl Acad Sci U S A
January 2025
California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720.
Polysaccharide monooxygenase (PMO) catalysis involves the chemically difficult hydroxylation of unactivated C-H bonds in carbohydrates. The reaction requires reducing equivalents and will utilize either oxygen or hydrogen peroxide as a cosubstrate. Two key mechanistic questions are addressed here: 1) How does the enzyme regulate the timely and tightly controlled electron delivery to the mononuclear copper active site, especially when bound substrate occludes the active site? and 2) How does this electron delivery differ when utilizing oxygen or hydrogen peroxide as a cosubstrate? Using a computational approach, potential paths of electron transfer (ET) to the active site copper ion were identified in a representative AA9 family PMO from (PMO9E).
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Institute of Medical Microbiology, Rheinisch-Westfälische Technische Hochschule Aachen University Hospital, Aachen 52074, Germany.
Postnatal establishment of enteric metabolic, host-microbial and immune homeostasis is the result of precisely timed and tightly regulated developmental and adaptive processes. Here, we show that infection with the invasive enteropathogen Typhimurium results in accelerated maturation of the neonatal epithelium with premature appearance of antimicrobial, metabolic, developmental, and regenerative features of the adult tissue. Using conditional Myd88-deficient mice, we identify the critical contribution of immune cell-derived mediators.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Cancer Biology & Genetics Program, Sloan Kettering Institute, New York, NY 10065.
Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive sarcomas and the primary cause of mortality in patients with neurofibromatosis type 1 (NF1). These malignancies develop within preexisting benign lesions called plexiform neurofibromas (PNs). PNs are solely driven by biallelic loss eliciting RAS pathway activation, and they respond favorably to MEK inhibitor therapy.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Department of Biological Sciences and Biotechnology, College of Natural Sciences, Chungbuk National University, Cheongju, Chungbuk, 28644, Republic of Korea.
Antimicrobial peptides (AMPs) are promising agents for treating antibiotic-resistant bacterial infections. Although discovering novel AMPs is crucial for combating multidrug-resistant bacteria and biofilm-related infections, their clinical potential relies on precise, real-time evaluation of efficacy, toxicity, and mechanisms. Optical diffraction tomography (ODT), a label-free imaging technology, enables real-time visualization of bacterial morphological changes, membrane damage, and biofilm formation over time.
View Article and Find Full Text PDFMedicine (Baltimore)
January 2025
Jumei Doctor Group Medical (Shenzhen) Co., Ltd, Shenzhen, China.
Rationale: Current research on antiviral treatment in children is relatively limited, especially in children under 1 year old.
Patient Concerns: Liu XX, an 8-month-old infant (case number: 3001120473), presented to the hospital in August 2016 with a chief complaint of being "hepatitis B surface antigen positive for 8 months and experiencing abnormal liver function for 5 months."
Diagnoses: The patient was diagnosed as chronic hepatitis B cirrhosis (G3S3-4) with active compensatory phase.
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