Biofilm Formation Research Articles

Lactams Exhibit Potent Antifungal Activity Against Monospecies and Multispecies Interkingdom Biofilms on a Novel Hydrogel Skin Model.

Infections of intact and damaged skin barriers and keratin are frequently associated with complex biofilm communities containing bacteria and fungi, yet there are limited options for successful management. This study intended to focus on the utility of some novel proprietary lactam molecules, quorum sensing (QS)-derived halogenated furanones, which act to block the QS pathway, against key fungal pathogens of the skin (Candida albicans, Malassezia furfur and Microsporum gypseum). Moreover, we aimed to assess how these actives performed against complex interkingdom biofilms in a clinically relevant model. Two lactam derivatives were tested against a panel of important fungal pathogens and then quantitatively assessed against simple and increasingly complex interkingdom biofilm models on polystyrene coverslips and a novel keratin hydrogel system. The lactams were shown to be effective against a wide range of fungal species in the planktonic and biofilm forms, with no ability to regrow. The fungal component of the multispecies biofilm models was significantly reduced with lactam treatment. Lactam treatment was also comparably effective compared to the non-prescription topical antifungal 'Lamisil' against C. albicans early and late biofilms. This study highlights the effectiveness of lactams as a novel antimicrobial for the management of the polymicrobial and interkingdom multispecies biofilms.

ZnO-Rutin nanostructure as a potent antibiofilm agent against Pseudomonas aeruginosa

Pseudomonas aeruginosa is a common human pathogen that is resistant to multiple antibiotics due to its ability to form biofilms. Developing novel nanoformulations capable of inhibiting and removing biofilms offers a promising solution for controlling biofilm-related infections. In this study, we investigated the anti-biofilm activity of rutin-conjugated ZnO nanoparticles (ZnO-Rutin NPs) in pathogenic strains of P. aeruginosa. The synthesized ZnO-Rutin NPs had amorphous shapes with sizes ranging from 14 to 100 nm. The broth microdilution assay revealed that ZnO-Rutin NPs, with an MIC value of 2 mg/mL, exhibit greater antimicrobial activity than ZnO NPs and rutin alone. Based on crystal violet staining, the biofilm inhibition rate by ½ MIC of the conjugated nanoparticles was recorded at above 90%. The significant reduction in exopolysaccharide (62.75–66.37%) and alginate (38.3–57.61%) levels, as well as the formation of thin biofilms in the ZnO-Rutin NP-treated group, confirmed the anti-biofilm potential of these nanoparticles. Additionally, a significant decrease in the metabolic activity and viable cells of mature biofilms was observed after exposure to the conjugated nanoparticles. Furthermore, ZnO-Rutin NPs considerably attenuated the expression of the Las-Rhl quorum-sensing transcriptional regulator genes (lasR and rhlR) in P. aeruginosa by 0.39–0.40 and 0.25–0.42 folds, respectively. This work demonstrated that ZnO-Rutin NPs are remarkably capable of inhibiting the initial stage of biofilm formation and eradicating mature biofilms, suggesting they could be a useful agent for treating P. aeruginosa biofilm-related infections.

Green synthesis and characterization of NiO/Hydroxyapatite nanocomposites in the presence of peppermint extract and investigation of their antibacterial activities against Pseudomonas aeruginosa and Staphylococcus aureus

In many areas, antibiotic resistance is becoming a serious concern for public health. As a result of the interesting structural properties of nanomaterials, nanoscience-based methods have emerged as promising ways to increase the movement of existing antimicrobials. In this study, pristine nickel oxide (NiO) nanoparticles, hydroxyapatite (HAP) nanoparticles, and binary nickel oxide/hydroxyapatite (NiO/HAP) nanocomposites were fabricated through peppermint extract-assisted green route. The obtained results revealed that peppermint extract can be a superior green capping agent for the preparation of NiO, HAP, and NiO/HAP nanomaterials. The bioactivity tests revealed the bactericidal and anti-biofilm activities of synthesized NiO, HAP, and NiO/HAP nanostructures against Pseudomonas aeruginosa (PAO1) and Staphylococcus aureus (ATCC 43300) bacteria. The findings confirmed that the prepared NiO/HAP nanocomposites have more effective antibacterial activity than pure NiO and HAP. For Staphylococcus aureus, the minimal inhibitory concentration (MIC) values for NiO, HAP, and NiO/HAP nanocomposites were determined to be of about 9.60, 13.03, and 3.41 mg/mL, respectively. For Pseudomonas aeruginosa, the MIC values for NiO, HAP, and NiO/HAP nanocomposites were estimated as 9.6, 13.50, and 1.7 mg/mL, respectively. Although, all synthesized samples are remarkable in their ability to prevent the formation of biofilms at MIC and sub-MIC concentrations (p < 0.01), NiO/HAP illustrated biofilm inhibitory activity up to 95 % for Pseudomonas aeruginosa and to 81 % for Staphylococcus aureus. In the present study, it was demonstrated that NiO/HAP nanocomposites prepared in a green environment can be excellent antibacterial agents against Staphylococcus aureus and Pseudomonas aeruginosa.

Liushen Wan alleviates the virulence and inflammation of Staphylococcus aureus via NLRP3 inflammasome and TLR2-NF-κB/p38 MAPK signaling pathways.

Infectious diseases have been a major threat to health worldwide, with bacterial infections being particularly prominent. Staphylococcus aureus (S. aureus) infections are associated with the most deaths. Inhibition of virulence factor and excessive inflammation induced by S. aureus has become a potential antibiotic alternative/synergistic therapy without causing greater survival pressure to prevent the emergence of "superbugs" in the future. Liushen Wan (LSW), a traditional Chinese medicine, used for multiple bacterial infectious diseases. In this work, we researched its therapeutic effect and explored the potential mechanism of LSW aiming at S. aureus in vivo and in vitro. Minimal inhibitory concentration (MIC) assay, hemolysis assay, invasion assay, staphyloxanthin assay and evolution of resistance assay were performed to show that LSW alleviated the virulence of S. aureus without suppressing S. aureus activity, and short-term use of LSW did not make bacteria resistant to it. Biofilm inhibition assay demonstrated that LSW inhibited the formation of biofilm and destroyed mature biofilm of S. aureus. In vitro experiments using RT-qPCR, ELISA and western blot analysis indicated LSW inhibited the inflammatory reaction triggered by HK-S. aureus and S. aureus through NLRP3 inflammasome and TLR2-NF-κB/p38 MAPK pathway. Moreover, LSW alleviated lung damage induced by S. aureus. Taken together, LSW is a promising antibacterial, anti-virulence and anti-inflammatory drug, which could provide the pharmacological basis on the traditional application of LSW for diseases associated with S. aureus infection in clinical.

Facile and green synthesis of Ag/Cu bimetallic nanoparticles using waste banana peel extract for effective corrosion inhibition of mixed sulfate-reducing bacteria.

Microbiologically induced corrosion (MIC) is widespread in the oilfield industry, and new environmentally friendly materials are urgently needed to inhibit MIC with the increasing environmental requirements and microbial resistance problems. The synthesis method and cost of the materials are important factors that must be considered in the production and application. In this study, Ag/Cu bimetallic nanoparticles (BNPs) were synthesized by eco-friendly and sustainable method using waste banana peel extract (BPE) as a green reducing. The antibacterial and corrosion inhibition properties of Ag/Cu BNPs were investigated by using the enriched mixed strains containing sulfate-reducing bacteria (SRB) as model bacteria. The results of electron microscopy showed that the prepared BNPs exhibited spherical structure with about 19.0nm in size. The synthesized nanoparticles significantly inhibited the growth of mixed strains by antimicrobial experiments with minimum inhibitory concentration (MIC) value of 9.38μg/mL. The addition of Ag/Cu BNPs (9.38μg/mL) inhibited the corrosion of X65 carbon steel induced by the mixed strains with 77.9% compared to the untreated condition. Correspondingly, the number of sessile SRB cells in the solution containing Ag/Cu BNPs (9.38μg/mL) after 28 days of immersion decreased by 5-log compared with the treatment group without nanomaterials (1.1×108cells/cm2). Furthermore, the observation of the surface morphology and strains cellular microstructure of carbon steel treated with nanoparticle materials illustrated that the corrosion inhibition mechanism mainly includes destroying cell structure, affecting metabolic activities and inhibiting biofilm formation. The environmentally friendly nanoparticle materials prepared in this study have great potential in the safe and clean production of oil fields.

Pore-scale modeling of biofilm formation and biofilm-induced anomalous transport features in heterogenous porous media

Pore-scale modeling of biofilm formation and biofilm-induced anomalous transport features in heterogenous porous media

Impact of Improved Sanitation Standard Operating Procedures on Microbial Populations at Three Tree Fruit Packing Facilities.

Cleaning and sanitizing are of vital importance to control Listeria monocytogenes in food processing facilities. Here, we evaluated the effect of four cleaning and sanitation standard operating procedures (SSOPs; T1, T2, T3, T4) on the reduction of total aerobic mesophilic microorganisms, the occurrence of L. monocytogenes, and the microbiota composition in three tree fruit packing facilities (F1, F2, and F3) over two packing seasons (Y1 and Y2). Environmental samples were collected from non-food contact surfaces before and after the application of SSOPs. Total aerobic bacteria were quantified using a standard plate count method, and Listeria spp. and L. monocytogenes concentration was quantified using a Most Probable Number method. Amplicon sequencing was used to determine bacterial and fungal microbiota composition, and Nanopore sequencing was used to detect functional elements in the microbiota that could promote the survival and persistence of L. monocytogenes in the studied environments. The use of SSOPs reduced the total bacterial load by 0.27-2.48 log10 CFU/swab (p≤0.001). Among the treatments tested, the inclusion of a biofilm remover in T4 was most effective in significantly reducing the total Listeria spp. concentration by 1.57-1.27 log10 MPN/swab (p<0.02) and the frequency of L. monocytogenes, although the latter was not statistically significant. We observed inconsistent changes in the bacterial and fungal microbiota composition due to the application of cleaning and sanitizing SSOPs, which may be due to the presence of dead DNA after the treatment. Using Nanopore sequencing, we detected functional elements related to biofilm formation and stress resistance in the microbiomes of the studied environments. Overall, our study shows that the implementation of SSOPs improved the sanitation outcomes in tree fruit packing facilities. There is a need for the future work to focus on optimizing and validating the standard operating procedures, especially in the areas in which SSOPs were less effective, such as those covered with wax residues.

Radical formation in skin and preclinical characterization of a novel medical plasma device for dermatology after single application.

Cold atmospheric plasma (CAP) enables painless tissue treatment by producing reactive species including excited molecules and charged particles and is of great interest for medical applications. Medical CAP sources work in contact with air at ambient pressure, resulting in the generation of substantial amounts of reactive oxygen and nitrogen radicals. These radicals have a significant influence on cellular biochemistry, are crucial components of the immune system, and play a central role in wound therapy. CAP has a variety of applications, with a particular emphasis on tissue treatment in dermatology. It eradicates microorganisms by preventing biofilm formation so that wounds can be effectively disinfected and treated antiseptically. Using both in vitro and ex vivo methods, a comprehensive preclinical assessment of a novel battery-operated cold plasma handheld device with a reusable, and autoclavable glass cylinder was performed. The objectives were to evaluate the potential impact of single CAP application on radical formation with and without wound dressing, by directly measuring radicals in skin, to investigate the influence of CAP application on antimicrobial activity and cytotoxicity in vitro, and to assess skin tolerance ex vivo. The direct effect of CAP on the formation of radicals in the skin after plasma application at different levels with and without wound dressing was demonstrated quantitatively for the first time using electron paramagnetic resonance spectroscopy. Free radicals were measured in the skin as a function of the duration of CAP treatment. Furthermore, it was found that an alginate or wound plaster dressing does not significantly inhibit radical formation in skin compared to application without a dressing. In vitro and ex vivo data showed no cytotoxic potential with simultaneous efficacy against bacteria strains and no risk of temperature rise, pH change, skin barrier or DNA damage. These results show a high potential for wound healing applications in vivo.

Silver functionalized chitosan composite hydrogel with sustained silver release and enhanced antibacterial properties promotes healing of infected wounds

Bacterial infections during wound healing often cause inflammation, which delays the healing process. Therefore, innovative wound dressings are urgently needed to inhibit bacterial infections and promote healing. This study proposes an Ag-functionalized chitosan hydrogel dressing, formed via a Schiff-base reaction between alkynyl Ag substituted chitosan (Ag-CS) and octafunctionalized polyhedral oligomeric silsesquioxane with benzaldehyde-terminated polyethylene glycol (POSS-PEG-CHO), to address the issue of bacterial infection in wounds. The hydrogel demonstrated excellent injectability and self-healing properties. AgNPs and alkynyl Ag, produced by the reducing effect of chitosan and the reversible reaction of alkynyl Ag, delay the release of Ag+. Furthermore, the hydrogel exhibits a broad-spectrum antibacterial effect and effectively inhibits bacterial biofilm formation. The release of Ag+ lasts for 7 days, ensuring sustainable antibacterial properties. In a mouse infected wound model, the composite hydrogel significantly accelerated wound healing. By the eighth day, the wound healing rate reached 99 %, whereas the control group achieved only 91 %. Histological and immunofluorescence staining results indicated that hydrogel-treated wounds had faster re-epithelialization, collagen deposition, and angiogenesis, with reduced inflammation. In conclusion, the Ag-functionalized chitosan hydrogel, with sustained Ag release and enhanced antibacterial properties, shows great potential as a wound dressing for promoting the healing of infected wounds.

Study on the relationship between microbial composition within obstructive biliary stents and the severity of obstruction and duration of stent placement.

Biliary stent occlusion is due, in part, to biofilm formation by bacteria. However, previous culture-based approaches may not have revealed all microorganisms on the surface. Twenty-seven patients underwent endoscopic retrograde biliary drainage for the removal or replacement of plastic biliary stents. We analyzed occlusion severity using image-analyses of a longitudinal section of the biliary stent and evaluated the microbial profile of sludge deposition inside the stents using 16S rRNA sequencing with a MiSeq Illumina platform. We then evaluated the association of microbial profiles with the duration of stent placement and stent occlusion severity. Actinobacteria and Synergistetes were much more abundant in occluded stents compared with non-occluded stents. An abundance of Bifidobacterium spp. and OTU00006 Bifidobacterium animalis (100%) correlated with stent occlusion severity (rho, 0.62; p<0.001; and 0.42; p = 0.03, respectively), and this relationship remained after adjusting for the duration of stent placement (p = 0.03 and 0.05, respectively). The genus Bifidobacterium and Bifidobacterium animalis were associated with the degree of occlusion in plastic biliary stents.

Revised Title - Quercetin Combined with Ciprofloxacin and Gentamicin Inhibits Biofilm Formation and Virulence in Staphylococcus aureus.

Revised Title - Quercetin Combined with Ciprofloxacin and Gentamicin Inhibits Biofilm Formation and Virulence in Staphylococcus aureus.

Graveyard effects of antimicrobial nanostructured titanium over prolonged exposure to drug resistant bacteria and fungi.

Innovations in nanostructured surfaces have found a practical place in the medical area with use in implant materials for post-operative infection prevention. These textured surfaces should be dual purpose: (1) bactericidal on contact and (2) resistant to biofilm formation over prolonged periods. Here, hydrothermally etched titanium surfaces were tested against two highly antimicrobial resistant microbial species, methicillin-resistant Staphylococcus aureus and Candida albicans. Two surface types - unmodified titanium and nanostructured titanium - were incubated in a suspension of each microbial strain for 1 day and 7 days. Surface topography and cross-sectional information of the microbial cells adhered to the surfaces, along with biomass volume and live/dead rate, showed that while nanostructured titanium was able to kill microbes after 1 day of exposure, after 7 days, the rate of death becomes negligible when compared to the unmodified titanium. This suggests that as biofilms mature on a nanostructured surface, the cells that have lysed conceal the nanostructures and prime the surface for planktonic cells to adhere, decreasing the possibility of structure-induced lysis. Synchrotron macro-attenuated total reflection Fourier transform infrared (macro ATR-FTIR) micro-spectroscopy was used to elucidate the biochemical changes occurring following exposure to differing surface texture and incubation duration, providing further understanding into the effects of surface morphology on the biochemical molecules (lipids, proteins and polysaccharides) in an evolving and growing microbial colony.

Computational exploration of the self-aggregation mechanisms of phenol-soluble modulins β1 and β2 in Staphylococcus aureus biofilms.

The formation of functional bacterial amyloids by phenol-soluble modulins (PSMs) in Staphylococcus aureus is a critical component of biofilm-associated infections, providing robust protective barriers against antimicrobial agents and immune defenses. Clarifying the molecular mechanisms of PSM self-assembly within the biofilm matrix is essential for developing strategies to disrupt biofilm integrity and combat biofilm-related infections. In this study, we analyzed the self-assembly dynamics of PSM-β1 and PSM-β2 by examining their folding and dimerization through long-timescale atomistic discrete molecular dynamics simulations. Our findings revealed that both peptides primarily adopt helical structures as monomers but shift to β-sheets upon dimerization. Monomeric state, PSM-β1 exhibited frequent transitions between helical and β-sheet forms, while PSM-β2 largely retained a helical structure. Upon dimerization, both peptides showed pronounced β-sheet formation around conserved C-terminal residues 21-44. Residues 21-33, largely unstructured as monomers, demonstrated strong tendencies for β-sheet formation and intermolecular interactions, underscoring their central role in the self-assembly of both peptides. Additionally, the PSM-β1 N-terminus formed β-sheets only when interacting with the C-terminus, whereas the PSM-β2 N-terminus remained helical and uninvolved in β-sheet formation. These distinct aggregation behaviors likely contribute to biofilm dynamics, with C-terminal regions facilitating biofilm formation and N-terminal regions influencing stability. Targeting residues 21-33 in PSM-β1 and PSM-β2 offers a promising therapeutic approach for disrupting biofilm integrity. This study advances our understanding of PSM-β1 and PSM-β2 self-assembly and presents new targets for drug design against biofilm-associated diseases.

Cosmopolitan but still untapped: Antimicrobial, antibiofilm and in silico molecular docking study on Caulerpa racemosa, Dictyopteris polypodioides and Padina pavonica

Egyptian seaweeds contain diverse bioactive compounds, but our understanding of their antimicrobial potential, particularly against multidrug-resistant (MDR) human pathogens, is still limited and underestimated. This study screened the antimicrobial potential of ethanolic extracts of Caulerpa racemosa, Dictyopteris polypodioides, and Padina pavonica against various MDR bacterial and fungal strains using broth microdilution technique. Antibiofilm assay of the seaweed extracts against Pseudomonas aeruginosa clinical isolates was also investigated. Our findings showed that the minimum inhibitory concentrations (MICs) of the tested seaweed extracts ranged between 62 and 500 μg mL−1. P. pavonica displayed the most biofilm inhibition percentages against P. aeruginosa clinical isolate by 31.2 % and 62.5 % for BIC50 and BIC90, respectively, as comparing to D. polypodioides and C. racemosa. Liquid chromatography-high resolution electrospray ionization mass spectrometry (LC-HR-ESI-MS) metabolic profiling of P. pavonica ethanolic extract was characterized. Twenty-seven metabolites were identified and checked for their inhibitory biofilm formation based on molecular docking simulation on LasR protein-specific quorum sensing. Interestingly, squalene (4), hydroperoxy-24 vinyl-24 cholesterol (18), fucoxanthol (21), flavoxanthin (22), and fucoxanthin (23) exhibited adequate interaction energies and formed significant interactions inside the LasR active site, supporting them to possess potent antibiofilm properties. Overall, P. pavonica can be recommended as powerful agent of antibiofilm preparation.

Metagenome-resolved functional traits of Rubrobacter species implicated in rosy discoloration of ancient frescoes in two Georgian Cathedrals.

Pink biofilm formation on stone monuments and mural paintings poses serious harm to cultural heritage preservation. Pink biofilms are globally widespread and recalcitrant to eradication, often causing recurrences after restoration. Yet, the ecological drivers of pink biofilm formation and the metabolic functions sustaining the growth of pigment-producing biodeteriogens remain unclear. In this study, a combined approach integrating physicochemical investigations, scanning electron microscopy, 16S rRNA sequence-based analysis of the prokaryotic community, metagenomic deep sequencing, and metabolic profiling, was applied to determine the etiology of rosy discoloration of ancient frescoes in the Gelati and the Martvili Cathedrals (Georgia). Martvili samples showed greater diversity than Gelati samples, though Actinomycetota predominated in both samples. Rubrobacter-related sequences were detected in all sampling sites, showing an overwhelming abundance in Gelati samples. Reconstruction of metagenome-assembled genomes (MAGs) and phylogenetic analyses highlighted significant intra-genus diversity for Rubrobacter-related sequences, most of which could not be assigned to any formally described Rubrobacter species. Metabolic profiling of the Gelati metagenomes suggests that carbon-fixing autotrophic bacteria and proteinaceous substances in the plaster could contribute to sustaining the chemoorganotrophic members of the community. Complete pathways for β-carotene and bacterioruberin synthesis were identified in Rubrobacter MAGs, consistent with the Raman spectroscopy-based detection of these pigments in fresco samples. Gene clusters for the synthesis of secondary metabolites endowed with antibiotic activity were predicted from the annotation of Rubrobacter MAGs, along with genes conferring resistance to several antimicrobials and biocides. In conclusion, genome-resolved metagenomics provided robust evidence of a causal relationship between contamination by Rubrobacter-related carotenoid-producing bacteria and the rosy discoloration of Georgian frescoes, with relevant implications for rational biodeteriogen-targeted restoration strategies.

New quinazolone-sulfonate conjugates with an acetohydrazide linker as potential antimicrobial agents: design, synthesis and molecular docking simulations.

A novel molecular design based on a quinazolinone scaffold was developed via the attachment of aryl alkanesulfonates to the quinazolinone core through a thioacetohydrazide azomethine linker, leading to a new series of quinazolinone-alkanesulfonates 5a-r. The antimicrobial properties of the newly synthesized quinazolinone derivatives 5a-r were investigated to examine their bactericidal and fungicidal activities against bacterial pathogens like Bacillus subtilis, Staphylococcus aureus (Gram-positive), Pseudomonas aeruginosa, Klebsiella pneumonia, Sallmonella Typhimurium (Gram-negative), in addition to Candida albicans (unicellular fungal). The tested compounds demonstrated reasonable bactericidal activities compared to standard drugs. Notably, derivatives 5g and 5k exhibited the greatest MIC values against Candida albicans, while 5g was the best against Staphylococcus aureus with MIC of 11.3 ± 2.38 μg mL-1, two-fold efficacy more than that was recorded with sulfadiazine. Furthermore, 5k significantly prevented biofilm formation for all bacterial pathogens, with a percentage ratio reaching 63.9%, surpassing the standard drug Ciprofloxacin. Additionally, 5k caused elevated lipid peroxidation (LPO) when added to the tested microbial pathogens. Confocal Laser Scanning Microscopy (CLSM) visualization revealed fewer live cells after treatment. Molecular docking studies showed that the quinazolinone derivatives bind strongly to the DNA gyrase enzyme, with the acid hydrazide core interacting effectively with key residues GLU50, ASN46, GLY77, and ASP136, consistent with their antimicrobial activity. Additionally, these compounds exhibited promising physicochemical properties, paving the way for discovering new antimicrobial drugs.

Uracil improves the freeze-drying resistance of Pediococcus acidilactici and Lactococcus lactis by increasing biofilm formation via the uridine monophosphate/LuxS/AI-2 pathway

Uracil improves the freeze-drying resistance of Pediococcus acidilactici and Lactococcus lactis by increasing biofilm formation via the uridine monophosphate/LuxS/AI-2 pathway

Discovery of new aliphatic metabolites with antibacterial activities from a soil-derived Streptomyces antifungus.

Fifteen new aliphatic metabolites, 2-methylpyrimidin-4(3H)-ones (1,2), 2-methoxy-2-methyl-1,2-dihydro-3H-pyrrol-3-ones (4a/4b, 5a/5b), butyrolactones (6-9), and aliphatic metabolites (16-20) as well as known pyridin-2(1H)-one (3) and butyrolactone analogues (10-15) were obtained from the fermentation broth of Streptomyces antifungus isolated from the forest soil sample collected in Tengchong, China. Pyrimidin-4(3H)-one derivatives (1, 2) with an individual 2-methylpyrimidin-4(3H)-one skeleton is a kind of rarely reported compound and were firstly obtained from natural source. The structures of the new metabolites were elucidated by comprehensive spectroscopic analysis including data from experimental and calculated ECD spectra as well as Mosher's reagent derivative method. Compounds 1, 2, 18, and 19 exhibited optimal activity against Staphylococcus aureus with MIC values ranged from 12.5 to 50 μg/mL. Further investigation revealed that 1 effectively inhibited biofilm formation and destroyed the preformed biofilm of S. aureus through oxidative damage, thereby exerting antibacterial effect.

Layer-by-layer coated probiotics with tannic acid-Ca2+ and casein phosphopeptide complexes for caries prevention and enamel remineralization.

Dental caries is a common disease resulting from tooth demineralization caused by bacterial plaque. Probiotics have shown great potential against caries by regulating the balance of oral flora. However, obstacles such as poor colonization and lysozyme sensitivity in oral cavity hinder their further application. In this study, an efficient layer-by-layer surface coating of tannic acid (TA)-Ca2+ and casein phosphopeptide (CPP) was applied to the probiotic Bifidobacterium infantis (BI) with potential anti-caries activity. Multi-functionalized probiotics thus prepared (called BI@TA-Ca2+@CPP) exhibited similar growth pattern, resistance to lysozyme and enhanced colonization potential. The ability of BI@TA-Ca2+@CPP in inhibiting cariogenic biofilm formation was improved. Moreover, BI@TA-Ca2+@CPP showed excellent remineralization efficacy. In a caries-induced rat model, BI@TA-Ca2+@CPP significantly prevented the occurrence and progression of tooth decay, meanwhile showing good biocompatibility. In summary, this study underlines the importance of probiotics coating in antibiofilm and remineralization activity as a promising strategy against dental caries.

Spent coffee ground disrupts Listeria monocytogenes biofilm formation through inhibition of motility and adhesion via quorum sensing regulation

Spent coffee ground disrupts Listeria monocytogenes biofilm formation through inhibition of motility and adhesion via quorum sensing regulation