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Diverse surgical approaches, such as resective, reconstructive, and combined therapy, have been proposed for peri-implantitis treatment. A resective surgical approach with an adjunctive modified implantoplasty refers to the modification of the implant body into a constricted area to mimic a "waist" silhouette. This modified technique forms an adequate concave smooth area that may favor the outcomes of resective surgical therapy for soft tissue adaptation, biofilm control, and possible peri-implant bone gain over the long term. The present case series aimed to exhibit the long-term clinical and radiographic outcomes of resective surgery with adjunctive implantoplasty over a 6- to 11-year follow-up. Four patients presenting four implants (one per patient) diagnosed with peri-implantitis (according to an established case definition) were included in the present case series. Patients underwent resective surgery, a modified implantoplasty approach, and implant surface decontamination. After surgical therapy, clinical and radiographic outcomes such as bleeding on probing (BoP), suppuration on probing (SoP), probing depth (PD), marginal recession (MR), modified plaque index (mPI), and marginal bone levels (MBLs) were recorded over a long-term follow-up period. Over the 6- to 11-year follow-up, mean BoP, PD, and SoP scores amounted to 17% ± 24%, 3.2 ± 0.66 mm, and 0%, respectively. Mean BoP, PD, and SoP scores were reduced by 67% ± 24%, 2.5 ± 1.26 mm, and 100%, respectively. Radiographic analysis revealed a mean radiographic bone gain of 3.1 ± 1.84 mm. Peri-implant marginal bone loss surface area decreased by 5.7 ± 3.77 mm2 over the long-term follow-up. Resective therapy with adjunctive implantoplasty promoted favorable clinical and radiographic outcomes at treated peri-implantitis sites over a long-term period. [ABSTRACT FROM AUTHOR]

Microbial fuel cells utilize exoelectrogenic microorganisms to directly convert organic matter into electricity, offering a compelling approach for simultaneous power generation and wastewater treatment. However, conventional microbial fuel cells typically require thick biofilms for sufficient metabolic electron production rate, which inevitably compromises mass and charge transport, posing a fundamental tradeoff that limits the achievable power density (

Bacterial biofilm formation and attachment to hosts are mediated by carbohydrate-binding lectins, exopolysaccharides, and their interactions in the extracellular matrix (ECM). During tomato infection Ralstonia pseudosolanacearum (Rps) GMI1000 highly expresses three lectins: LecM, LecF, and LecX. The latter two are uncharacterized. We evaluated the roles in bacterial wilt disease of LecF, a fucose-binding lectin, LecX, a xylose-binding lectin, and the Rps exopolysaccharide EPS I. Interestingly, single and double lectin mutants attached to tomato roots better and formed more biofilm under static conditions in vitro. Consistent with this finding, static bacterial aggregation was suppressed by heterologous expression of lecFGMI1000 and lecXGMI1000 in other Ralstonia strains that naturally lack these lectins. Crude ECM from a ΔlecF/X double mutant was more adhesive than the wild-type ECM, and LecF and LecX increased Rps attachment to ECM. The enhanced adhesiveness of the ΔlecF/X ECM could explain the double mutants hyper-attachment in static conditions. Unexpectedly, mutating lectins decreased Rps attachment and biofilm viscosity under shear stress, which this pathogen experiences in plant xylem. LecF, LecX, and EPS I were all essential for biofilm development in xylem fluid flowing through cellulose-coated microfluidic channels. These results suggest that under shear stress, LecF and LecX increase Rps attachment by interacting with the ECM and plant cell wall components like cellulose. In static conditions such as on root surfaces and in clogged xylem vessels, the same lectins suppress attachment to facilitate pathogen dispersal. Thus, Rps lectins have a dual biological function that depends on the physical environment.

Plastic waste, especially positively buoyant polymers known as polyolefins, are a major component of floating debris in the marine environment. While plastic colonisation by marine microbes is well documented from environmental samples, the succession of marine microbial community structure over longer time scales (> > 1 month) and across different types and shapes of plastic debris is less certain. We analysed 16S rRNA and 18S rRNA amplicon gene sequences from biofilms on polyolefin debris floating in a flow-through seawater tank in Hawaii to assess differences in microbial succession across the plastic types of polypropylene (PP) and both high-density polyethylene (HDPE) and low-density polyethylene (LDPE) made of different plastic shapes (rod, film and cube) under the same environmental conditions for 1 year. Regardless of type or shape, all plastic debris were dominated by the eukaryotic diatom Nitzschia, and only plastic type was significantly important for bacterial community structure over time (p = 0.005). PE plastics had higher differential abundance when compared to PP for 20 bacterial and eight eukaryotic taxa, including the known plastic degrading bacterial taxon Hyphomonas (p = 0.01). Results from our study provide empirical evidence that plastic type may be more important for bacterial than eukaryotic microbial community succession on polyolefin pollution under similar conditions.

UNLABELLED: Motility promotes biofilm initiation during the early steps of this process: microbial surface association and attachment. Motility is controlled in part by chemotaxis signaling, so it seems reasonable that chemotaxis may also affect biofilm formation. There is a gap, however, in our understanding of the interactions between chemotaxis and biofilm formation, partly because most studies analyzed the phenotype of only a single chemotaxis signaling mutant, e.g., cheA. Here, we addressed the role of chemotaxis in biofilm formation using a full set of chemotaxis signaling mutants in Helicobacter pylori, a class I carcinogen that infects more than half the worlds population and forms biofilms. Using mutants that lack each chemotaxis signaling protein, we found that chemotaxis signaling affected the biofilm initiation stage, but not mature biofilm formation. Surprisingly, some chemotaxis mutants elevated biofilm initiation, while others inhibited it in a manner that was not tied to chemotaxis ability or ligand input. Instead, the biofilm phenotype correlated with flagellar rotational bias. Specifically, mutants with a counterclockwise bias promoted biofilm initiation, e.g., ∆cheA, ∆cheW, or ∆cheV1; in contrast, those with a clockwise bias inhibited it, e.g., ∆cheZ, ∆chePep, or ∆cheV3. We tested this correlation using a counterclockwise bias-locked flagellum, which induced biofilm formation independent of the chemotaxis system. These CCW flagella, however, were not sufficient to induce biofilm formation, suggesting there are downstream players. Overall, our work highlights the new finding that flagellar rotational direction promotes biofilm initiation, with the chemotaxis signaling system operating as one mechanism to control flagellar rotation. IMPORTANCE: Chemotaxis signaling systems have been reported to contribute to biofilm formation in many bacteria; however, how they regulate biofilm formation remains largely unknown. Chemotaxis systems are composed of many distinct kinds of proteins, but most previous work analyzed the biofilm effect of loss of only a few. Here, we explored chemotaxis role during biofilm formation in the human-associated pathogenic bacterium Helicobacter pylori. We found that chemotaxis proteins are involved in biofilm initiation in a manner that correlated with how they affected flagellar rotation. Biofilm initiation was high in mutants with counterclockwise (CCW) flagellar bias and low in those with clockwise bias. We supported the idea that a major driver of biofilm formation is flagellar rotational direction using a CCW-locked flagellar mutant, which stays CCW independent of chemotaxis input and showed elevated biofilm initiation. Our data suggest that CCW-rotating flagella, independent of chemotaxis inputs, are a biofilm-promoting signal.

Purpose: This study aimed to investigate the inhibitory effect of a PRG Barrier Coat on biofilm formation and structure by Streptococcus mutans and propose an effective method for preventing dental caries. Materials and Methods: Streptococcus mutans MT8148 biofilms were obtained from hydroxyapatite disks with and without a PRG Barrier Coat. Scanning electron microscopy (SEM) was used to observe the 12- and 24-h-cultured biofilms, while reverse-transcription polymerase chain reaction (qRT-PCR) was used to quantify caries-related genes. Biofilm adhesion assessments were performed on glass. Statistical analysis was performed using a two-sample t-test. Results: A statistically significant difference in Streptococcus mutans biofilm adhesion rate was observed between the control and PRG Barrier Coat-coated samples (p < 0.01). However, there was no statistically significant difference in total bacterial count or biofilm volume (p > 0.05). SEM revealed that the PRG Barrier Coat inhibited biofilm formation by Streptococcus mutans. Real-time RT-PCR revealed that the material restricted the expression of genes associated with caries-related biofilm formation. However, the suppression of gtfD and dexB differed from that of other genes. Conclusion: PRG Barrier Coat suppressed biofilm formation by Streptococcus mutans by inhibiting the expression of insoluble glucan synthase, which is associated with primary biofilm formation. The material also affected gene expression and altered the biofilm structure. Tooth surface-coating materials, such as PRG Barrier Coat, may improve caries prevention in dental practice. [ABSTRACT FROM AUTHOR]

The aim of this morphometric study was to precisely determine the 3D characteristics of the root complex of the posterior dentition. Extracted and well-preserved permanent posterior teeth were included in this analysis and grouped based on tooth type and arch location. All teeth were digitally scanned. Morphologic and dimensional features of the root complex were assessed, including length and surface area of the root trunk and individual roots, width of root concavities (RC), and furcation entrance, when present. A total of 240 posterior teeth comprised the study sample. The root complex of multirooted maxillary first premolars presented with a long root trunk (10.49 mm), representing 65.52% of the surface area, and two short roots comprising the remaining 34.8% of the surface area. Root trunks of mandibular molars were an average of 0.8 mm shorter than their maxillary counterparts. Class III furcation involvement is expected in all maxillary and mandibular molars, as well as multirooted maxillary first premolars, after 4.80 mm and 10.49 mm of clinical attachment loss, respectively. RCs were a common finding among the evaluated dentitions. The root complex morphology varies among the maxillary and mandibular posterior dentition. RCs are highly prevalent in both maxillary and mandibular dentition. The findings derived from this study can be utilized in daily clinical practice for the adequate management of posterior dentition and serve as a reference for future investigations in dental anatomy and digital technology. Also, these findings can guide the industry into creating and redefining tools that adequately adapt to the anatomical characteristics and variations of the specific tooth type. [ABSTRACT FROM AUTHOR]

Microbial biofilms represent an important lifestyle for bacteria and are dynamic three-dimensional structures. Cyclic dimeric guanosine monophosphate (c-di-GMP) is a ubiquitous signaling molecule that is known to be tightly regulated with biofilm processes. While measurements of global levels of c-di-GMP have proven valuable toward understanding the genetic control of c-di-GMP production, there is a need for tools to observe the local changes of c-di-GMP production in biofilm processes. We have developed a label-free method for the direct detection of c-di-GMP in microbial colony biofilms using matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI). We applied this method to the enteric pathogen Vibrio cholerae, the marine symbiont V. fischeri, and the opportunistic pathogen Pseudomonas aeruginosa PA14 and detected spatial and temporal changes in c-di-GMP signal that accompanied genetic alterations in factors that synthesize and degrade the compound. We further demonstrated how this method can be simultaneously applied to detect additional metabolites of interest from a single sample.

Impaired healing wounds do not proceed through the normal healing processes in a timely and orderly manner, and while they do eventually heal, their healing is not optimal. Chronic wounds, on the other hand, remain unhealed for weeks or months. In the US alone, chronic wounds impact ~8.5 million people and cost ~USD 28-90 billion per year, not accounting for the psychological and physical pain and emotional suffering that patients endure. These numbers are only expected to rise in the future as the elderly populations and the incidence of comorbidities such as diabetes, hypertension, and obesity increase. Over the last few decades, scientists have used a variety of approaches to treat chronic wounds, but unfortunately, to date, there is no effective treatment. Indeed, while there are thousands of drugs to combat cancer, there is only one single drug approved for the treatment of chronic wounds. This is in part because wound healing is a very complex process involving many phases that must occur sequentially and in a timely manner. Furthermore, models that fully mimic human chronic wounds have not been developed. In this review, we assess various models currently being used to study the biology of impaired healing and chronic non-healing wounds. Among them, this paper also highlights one model which shows significant promise; this model uses aged and obese db/db-/- mice and the chronic wounds that develop show characteristics of human chronic wounds that include increased oxidative stress, chronic inflammation, damaged microvasculature, abnormal collagen matrix deposition, a lack of re-epithelialization, and the spontaneous development of multi-bacterial biofilm. We also discuss how important it is that we continue to develop chronic wound models that more closely mimic those of humans and that can be used to test potential treatments to heal chronic wounds.

Biofilms are matrix-encased microbial communities that increase the environmental fitness and infectivity of many human pathogens including Vibrio cholerae. Biofilm matrix assembly is essential for biofilm formation and function. Known components of the V. cholerae biofilm matrix are the polysaccharide Vibrio polysaccharide (VPS), matrix proteins RbmA, RbmC, Bap1, and extracellular DNA, but the majority of the protein composition is uncharacterized. This study comprehensively analyzed the biofilm matrix proteome and revealed the presence of outer membrane proteins (OMPs). Outer membrane vesicles (OMVs) were also present in the V. cholerae biofilm matrix and were associated with OMPs and many biofilm matrix proteins suggesting that they participate in biofilm matrix assembly. Consistent with this, OMVs had the capability to alter biofilm structural properties depending on their composition. OmpU was the most prevalent OMP in the matrix, and its absence altered biofilm architecture by increasing VPS production. Single-cell force spectroscopy revealed that proteins critical for biofilm formation, OmpU, the matrix proteins RbmA, RbmC, Bap1, and VPS contribute to cell-surface adhesion forces at differing efficiency, with VPS showing the highest efficiency whereas Bap1 showing the lowest efficiency. Our findings provide new insights into the molecular mechanisms underlying biofilm matrix assembly in V. cholerae, which may provide new opportunities to develop inhibitors that specifically alter biofilm matrix properties and, thus, affect either the environmental survival or pathogenesis of V. cholerae.IMPORTANCECholera remains a major public health concern. Vibrio cholerae, the causative agent of cholera, forms biofilms, which are critical for its transmission, infectivity, and environmental persistence. While we know that the V. cholerae biofilm matrix contains exopolysaccharide, matrix proteins, and extracellular DNA, we do not have a comprehensive understanding of the majority of biofilm matrix components. Here, we discover outer membrane vesicles (OMVs) within the biofilm matrix of V. cholerae. Proteomic analysis of the matrix and matrix-associated OMVs showed that OMVs carry key matrix proteins and Vibrio polysaccharide (VPS) to help build biofilms. We also characterize the role of the highly abundant outer membrane protein OmpU in biofilm formation and show that it impacts biofilm architecture in a VPS-dependent manner. Understanding V. cholerae biofilm formation is important for developing a better prevention and treatment strategy framework.

Pustular mats from Shark Bay, Western Australia, host complex microbial communities bound within an organic matrix. These mats harbour many poorly characterized organisms with low relative abundances (

Reductions in nonresidential water demand during the COVID-19 pandemic highlighted the importance of understanding how water age impacts drinking water quality and microbiota in piped distribution systems. Using benchtop model distribution systems, we aimed to characterize the impacts of elevated water age on microbiota in bulk water and pipe wall biofilms. Five replicate constant-flow reactors were fed with municipal chloraminated tap water for 6 months prior to building closures and 7 months after. After building closures, chloramine levels entering the reactors dropped; in the reactor bulk water and biofilms the mean cell counts and ATP concentrations increased over an order of magnitude while the detection of opportunistic pathogens remained low. Water age, and the corresponding physicochemical changes, strongly influenced microbial abundance and community composition. Differential initial microbial colonization also had a lasting influence on microbial communities in each reactor (i.e., historical contingency).

Biofilms aid bacterial adhesion to surfaces via direct and indirect mechanisms, and formation of biofilms is considered as an important strategy for adaptation and survival in suboptimal environmental conditions. However, the molecular underpinnings of biofilm formation in subsurface sediment/groundwater ecosystems where microorganisms often experience fluctuations in nutrient input, pH, and nitrate or metal concentrations are underexplored. We examined biofilm formation under different nutrient, pH, metal, and nitrate regimens of 16 Rhodanobacter strains isolated from subsurface groundwater wells spanning diverse levels of pH (3.5 to 5) and nitrates (13.7 to 146 mM). Eight Rhodanobacter strains demonstrated significant biofilm growth under low pH, suggesting adaptations for survival and growth at low pH. Biofilms were intensified under aluminum stress, particularly in strains possessing fewer genetic traits associated with biofilm formation, findings warranting further investigation. Through random barcode transposon-site sequencing (RB-TnSeq), proteomics, use of specific mutants, and transmission electron microscopy analysis, we discovered flagellar loss under aluminum stress, indicating a potential relationship between motility, metal tolerance, and biofilm growth. Comparative genomic analyses revealed the absence of flagella and chemotaxis genes and the presence of a putative type VI secretion system in the highly biofilm-forming strain FW021-MT20. In this study we identified genetic determinants associated with biofilm growth under metal stress in a predominant environmental genus, Rhodanobacter, and identified traits aiding survival and adaptation to contaminated subsurface environments.

Methicillin-resistant Staphylococcus aureus (MRSA) is an important zoonotic pathogen associated with a wide range of infections in humans and animals. Thus, the emergence of MRSA clones poses an important threat to human and animal health. This study is aimed at elucidating the genomics insights of a strong biofilm-producing and multidrug-resistant (MDR) S. aureus MTR_BAU_H1 strain through whole-genome sequencing (WGS). The S. aureus MTR_BAU_H1 strain was isolated from food handlers hand swabs in Bangladesh and phenotypically assessed for antimicrobial susceptibility and biofilm production assays. The isolate was further undergone to high throughput WGS and analysed using different bioinformatics tools to elucidate the genetic diversity, molecular epidemiology, sequence type (ST), antimicrobial resistance, and virulence gene distribution. Phenotypic analyses revealed that the S. aureus MTR_BAU_H1 strain is a strong biofilm-former and carries both antimicrobial resistance (e.g., methicillin resistance; mecA, beta-lactam resistance; blaZ and tetracycline resistance; tetC) and virulence (e.g., sea, tsst, and PVL) genes. The genome of the S. aureus MTR_BAU_H1 belonged to ST1930 that possessed three plasmid replicons (e.g., rep16, rep7c, and rep19), seven prophages, and two clustered regularly interspaced short palindromic repeat (CRISPR) arrays of varying sizes. Phylogenetic analysis showed a close evolutionary relationship between the MTR_BAU_H1 genome and other MRSA clones of diverse hosts and demographics. The MTR_BAU_H1 genome harbours 42 antimicrobial resistance genes (ARGs), 128 virulence genes, and 273 SEED subsystems coding for the metabolism of amino acids, carbohydrates, proteins, cofactors, vitamins, minerals, and lipids. This is the first-ever WGS-based study of a strong biofilm-producing and MDR S. aureus strain isolated from human hand swabs in Bangladesh that unveils new information on the resistomes (ARGs and correlated mechanisms) and virulence potentials that might be linked to staphylococcal pathogenesis in both humans and animals.

BackgroundBiofilms in sulfide-rich springs present intricate microbial communities that play pivotal roles in biogeochemical cycling. We studied chemoautotrophically based biofilms that host diverse CPR bacteria and grow in sulfide-rich springs to investigate microbial controls on biogeochemical cycling.ResultsSulfide springs biofilms were investigated using bulk geochemical analysis, genome-resolved metagenomics, and scanning transmission X-ray microscopy (STXM) at room temperature and 87 K. Chemolithotrophic sulfur-oxidizing bacteria, including Thiothrix and Beggiatoa, dominate the biofilms, which also contain CPR Gracilibacteria, Absconditabacteria, Saccharibacteria, Peregrinibacteria, Berkelbacteria, Microgenomates, and Parcubacteria. STXM imaging revealed ultra-small cells near the surfaces of filamentous bacteria that may be CPR bacterial episymbionts. STXM and NEXAFS spectroscopy at carbon K and sulfur L2,3 edges show that filamentous bacteria contain protein-encapsulated spherical elemental sulfur granules, indicating that they are sulfur oxidizers, likely Thiothrix. Berkelbacteria and Moranbacteria in the same biofilm sample are predicted to have a novel electron bifurcating group 3b [NiFe]-hydrogenase, putatively a sulfhydrogenase, potentially linked to sulfur metabolism via redox cofactors. This complex could potentially contribute to symbioses, for example, with sulfur-oxidizing bacteria such as Thiothrix that is based on cryptic sulfur cycling. One Doudnabacteria genome encodes adjacent sulfur dioxygenase and rhodanese genes that may convert thiosulfate to sulfite. We find similar conserved genomic architecture associated with CPR bacteria from other sulfur-rich subsurface ecosystems.ConclusionsOur combined metagenomic, geochemical, spectromicroscopic, and structural bioinformatics analyses of biofilms growing in sulfide-rich springs revealed consortia that contain CPR bacteria and sulfur-oxidizing Proteobacteria, including Thiothrix, and bacteria from a new family within Beggiatoales. We infer roles for CPR bacteria in sulfur and hydrogen cycling. Video Abstract.

Since the discovery of antibiotics, they have served as a potent weapon against bacterial infections; however, natural evolution has allowed bacteria to adapt and develop coping mechanisms, ultimately leading to the concerning escalation of multidrug resistance. Bacterial persisters are a subpopulation that can survive briefly under high concentrations of antibiotic treatment and resume growth after lethal stress. Importantly, bacterial persisters are thought to be a significant cause of ineffective antibiotic therapy and recurrent infections in clinical practice and are thought to contribute to the development of antibiotic resistance. Therefore, it is essential to elucidate the molecular mechanisms of persister formation and to develop precise medical strategies to combat persistent infections. However, there are many difficulties in studying persisters due to their small proportion in the microbiota and their non-heritable nature. In this review, we discuss the similarities and differences of antibiotic resistance, tolerance, persistence, and viable but non-culturable cells, summarize the molecular mechanisms that affect the formation of persisters, and outline the emerging technologies in the study of persisters. [ABSTRACT FROM AUTHOR]

Foodborne diseases induced by foodborne pathogens have become a global concern, which cause massive food waste and enormous economic losses, and even impose serious threats to human health because of the production of bacterial toxins. Although synthetic chemical preservatives exhibit efficient antibacterial effects, their abuse and overuse have raised a variety of health concerns and led to an increase in drug-resistant bacteria. Recently, an increasing demand for "clean label" foods from consumers has stimulated the interest in developing novel food preservative techniques. Lactiplantibacillus plantarum (L. plantarum) is considered the most promising alternative to control bacterial growth, and subsequent bacterial toxin production and biofilm formation due to its production of a vast spectrum of antibacterial metabolites and/or competitive exclusion mechanisms. In addition, the potential application of L. plantarum to circumvent foodborne pathogenic bacteria has been exploited in varieties of food products. The aim of this review is to emphasize the significant antibacterial and anti-virulence properties of L. plantarum against foodborne pathogens and provide the most recent updates on the capacity of L. plantarum to serve as antibacterial and anti-virulence natural agent, thereby highlighting the promising potential in food bio-preservation. [ABSTRACT FROM AUTHOR]

Mycobacterium abscessus is a biofilm-forming, non-tuberculous mycobacterium that is highly resistant to antibiotics. Bacterial efflux pumps contribute to biofilm formation, export of biofilm-associated lipids and antibiotic tolerance. The Resistance Nodulation Cell Division (RND) and ATP-Binding Cassette (ABC) families of efflux pumps export lipids to the mycobacterial cell surface. 1-(1-naphthyl methyl)-piperazine (NMP) is a chemosensitizer that causes membrane destabilization and is an inhibitor of RND efflux pumps. The effects of NMP on biofilm formation and lipid metabolism in M. abscessus biofilms have not been investigated. Plumbagin (PLU) is an inhibitor of ABC efflux pumps that has not been studied for its effects on antibiotic tolerance in M. abscessus biofilms. In this study, we report that the efflux pump inhibitors NMP and PLU inhibit biofilm formation by 50% at sub-MIC levels. We show that NMP inhibits the incorporation of the radiolabeled long-chain fatty acid 14C-palmitate into glycopeptidolipids in cell surface lipids of log-phase M. abscessus. NMP also inhibits the utilization of the radiolabel in the biosynthesis of phosphatidylethanolamine in the cell surface and cellular lipids of M. abscessus cells in log-phase and in biofilms. Incorporation of the radiolabel into cardiolipin in the cellular lipids of M. abscessus biofilms was inhibited by NMP. The incorporation of 14C-acetate into cell surface phosphatidylethanolamine in log-phase and biofilm cells was also inhibited by NMP. Triacylglycerol biosynthesis using 14C-palmitate and 14C-acetate in cellular lipids of log-phase and biofilm cells was increased several folds by NMP. Efflux pump activity in M. abscessus cells was inhibited by 97% and 68% by NMP and PLU respectively. NMP and PLU caused 5-fold decreases in the minimum inhibitory concentrations of ciprofloxacin and clarithromycin against M. abscessus. Our results demonstrate that NMP and PLU affect important physiological processes in M. abscessus associated with its pathogenesis. [ABSTRACT FROM AUTHOR]

It is reported that bacteria can generate nanomotion, but understanding the complex dynamics of bacterial colony gliding on solid interfaces has remained unresolved. Here, this work captures the real‐time development and gliding of bacterial biofilms on vibrating solids made of piezoelectric quartz. The gliding, characterized by liquid slips, is measured in form of frequency and dissipation changes of the vibrating solid. These vibrations enable the generation of distinct acoustic fingerprints (sound/ music) of the three phases of biofilm development: viscoelastic strengthening, biofilm growth and biofilm stability. In adition, the effect of extracellular matrix secretion on the rigidity of the film and its nanoslip in each of the distinct biofilm developmental phases is quantified. This work provides a real‐time, label‐free method of quantifying bacteria biofilm dynamics and paves the way for developing libraries of acoustic signatures of bacteria and their metabolic products. [ABSTRACT FROM AUTHOR]

The rapid growth of the world's population and its environmental impact has increased the demand for effective water treatment methods. Surface water systems, including rivers, streams, lakes, and ponds, have suffered contamination, leading to the urgent need for effective contaminant removal. Organic nitrogen compounds and nitrates are of particular concern because they pose risks to health and can cause environmental damage. However, traditional water‐treatment methods often prove ineffective for addressing these issues. For this reason, this research focuses on harnessing the capabilities of nitrifying bacteria to denitrify organic nitrogen compounds in water, exploring various bacterial strains, their functions, and their ability to obtain sources of carbon. The study also investigates innovative approaches such as biofilm systems, mixed cultures, and combined processes, which have shown stronger potential for nitrogen removal. Overall, it provides valuable insights into the use of nitrifying bacteria‐based technologies for water remediation in the face of growing environmental challenges. [ABSTRACT FROM AUTHOR]

Background: Biofilm formation has a crucial role in the cariogenic virulence of Streptococcus mutans, which leads to resistance to common antibacterials. The antimicrobial resistance crisis has led to increased research about traditional natural products. Purpose: Quercus infectoria extract (QI extract) and nano hydrogels containing QI extract (QI-NH) and tannic acid (TA-NH) were evaluated against this pathogen. Methods: QI extract was analyzed by HPLC and the physiological characteristics of nanohydrogels were assessed by SEM, FTIR, zeta potential, DLS and determination of release kinetics and encapsulation efficiency. Determination of MIC and MBC of the material and their anti-biofilm effect was done by the microtiter method and on the extracted tooth surface. The properties of extracts and nano hydrogels in the expression of genes codifying glucosyltransferases (gtfB, gtfC and gtfD) and glucan binding protein B (gbpB) were quantified. Their toxicity was tested by the MTT method against the KB cell line. Results: According to HPLC, 55.18% of QI extract contained TA. The encapsulation efficiency of QI-NH and TA-NH was equal to 60% and 80%, respectively. SEM and FTIR exhibited that QI extract and TA were successfully entrapped in the networks resulting from the chemical bonding of chitosan and TPP. The average size of QI-NH and TA-NH was 70.45 and 58.43 nm, and their zeta potential was 6.17 ± 2.58 and 0.25 ± 0.03 mv, respectively. PDI < 0.3 of nano hydrogels indicated the favorable polydispersity of nanohydrogels. MIC of QI extract, QI-NH and TA-NH were 937.5, 30 and 10 µg/ml, respectively. Also their MBIC50 was 35.1, 2.1 and 0.95 µg/ml, respectively, and the extracts and nano hydrogels restrained the biofilm maturation on enamel. The pivotal genes of S. mutans in biofilm formation were significantly less expressed by treatment with QI-NH and TA-NH than others. Based on the MTT test, QI-NH had less acute toxicity than QI extract and TA-NH. IC50 of QI-NH was calculated as 775.4 µg/ml, while it was equal to 3.12 µg/ml for chlorhexidine as a common antibacterial agent. Conclusion: QI-NH, a new formulation derived from traditional anti-caries, can be a safe and efficient option to combat dental biofilm. [ABSTRACT FROM AUTHOR]

In respiratory pathogens such as Streptococcus pneumoniae , biofilm formation is associated with the colonization of the nasopharynx and chronic respiratory infection. Previous data have shown that pneumococcal conjugate vaccines (PCVs) had an impact on S. pneumoniae colonization and a potential replacement by other respiratory pathogens such as Staphylococcus aureus. The objective of this work was to evaluate the evasion of the immune system by monospecific biofilms and by S. aureus-S. pneumoniae mixed biofilms. We performed opsonophagocytosis assays (OPA) using human HL-60 against previously disaggregated monospecific biofilms of MSSA, MRSA and S. aureus-S. pneumoniae mixed biofilms. We used pre-immune and post-immune serum from immunocompetent adult patients vaccinated with PCV13. Immune sera had a clear effect in reducing pneumococcal biofilms of serotypes 3, 14, 18C, 19F and 19A, whereas had no effect in non-PCV13 serotypes such as 8, 11A and 24F. Our study confirmed that serum from vaccinated patients with PCV13 did not have any effect in reducing S. aureus population in monospecific biofilms, regardless the methicillin resistance phenotype. Moreover, immunized sera from vaccinated patients with PCV13 did not have any effect in S. aureus population in the mixed biofilm, whereas significantly reduced the population of pneumococcal serotype 19A strain in the mixed biofilm which is of great interest because this serotype is included in PCV13, and it is associated with vaccine failures. [ABSTRACT FROM AUTHOR]

The human body is colonized by a diverse community of microorganisms that are crucial for human health, while microbiota homeostasis is modulated by both environmental and host-derived cues. Specific microbial species form surface-attached microcolonies surrounded by their self-generated extracellular polymeric substances called biofilms. These complex assemblies may protect commensal bacteria, serving as a barrier against pathogenic microorganisms as well as hostile conditions, thus creating structuralized microbial communities for complex microbial interactions. However, biofilms formed by pathogenic bacteria will lead to invasion and perturbance of microbiota homeostasis, potentially leading to dysbiosis and diseases. In this review, we provide an in-depth analysis of the multiple-species biofilms on microbiota homeostasis within the human body. We describe the nature of biofilms in various anatomical regions, emphasizing their protective role against pathogenic invasions and their potential roles in causing disease under certain conditions. We also explore the microbial interactions between biofilms and microbial communities, emphasizing the significant potential of biofilms to alter the structure and composition of microbial assemblages. Finally, we suggest the directions for future biofilm research to enhance our understanding of the pathogenesis of diseases related to microbial dysbiosis and human health. [ABSTRACT FROM AUTHOR]

Background: Conventional antibacterial compounds can inhibit the growth of microorganisms, but their adverse effects and the development of drug limit their widespread use. The current study aimed to synthesize PEG-coated UIO-66-NH2 nanoparticles loaded with vancomycin and amikacin (VAN/AMK-UIO-66-NH2@PEG) and evaluate their antibacterial and anti-biofilm activities against vancomycin-resistant Staphylococcus aureus (VRSA) clinical isolates. Methods: The VAN/AMK-UIO-66-NH2@PEG were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and dynamic light scattering (DLS) to determine their size, polydispersity index (PDI), encapsulation efficiency (EE%), zeta-potential, drug release profile, and physical stability. Antibacterial activity was evaluated using minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and time-kill assays. Biofilm formation by VRSA was assessed using the crystal violet (CV) and minimum biofilm eradication concentration (MBEC) assays. The effect of sub-MIC concentrations of the formulations on the expression of biofilm-related genes (icaA, icaD) and resistance-related genes (mecA, vanA) was investigated using quantitative real-time polymerase chain reaction (RT-qPCR). Results: As demonstrated by MIC, MBC and time-kill assay, the VAN/AMK-UIO-66-NH2@PEG nanoparticles exhibited enhanced antibacterial activity against VRSA isolates compared to free drugs and prepared formulations. Furthermore, CV and MBEC tests indicated that the VAN/AMK-UIO-66@NH2/PEG can reduce biofilm formation dramatically compared to VAN/AMK and VAN/AMK-UIO-66@NH2, due to its great drug release properties. This study also found that the expression level of the mecA, vanA, icaA, and icaD genes in VAN/AMK-UIO-66@NH2/PEG treated VRSA isolates was substantially decreased compared to other groups. Conclusions: These findings highlighted the efficiency of VAN/AMK-UIO-66@NH2/PEG in combating antimicrobial resistance and biofilm formation in VRSA isolates. Future studies, particularly in vivo models, are necessary to evaluate the safety, efficacy, and clinical applicability of these nanoparticles for the treatment of bacterial infections. [ABSTRACT FROM AUTHOR]

Background Methods Results Conclusion Chronic rhinosinusitis (CRS) is a persistent inflammatory condition of the sinus mucosa. While Staphylococcus aureus has been shown to play a significant role in mucosal barrier disruption in CRS patients, coagulase‐negative staphylococci (CoNS) such as Staphylococcus epidermidis and Staphylococcus lugdunensis are also implicated in CRS pathophysiology. This study investigates the effects of exoproteins secreted by planktonic and biofilm forms of clinical isolates of S. epidermidis and S. lugdunensis on the nasal epithelial barrier.Thirty‐one clinical isolates of CoNS were grown in planktonic and biofilm forms, and their exoproteins were concentrated. The epithelial barrier structure was assessed by measuring transepithelial electrical resistance (TEER) and the permeability of fluorescein isothiocyanate‐dextran. Toxicity and inflammatory response were also studied.Our findings demonstrate that exoproteins from all planktonic forms of S. lugdunensis disrupted the mucosal barrier, whereas only nine of 16 biofilm‐derived exoproteins had similar effects. Conversely, 11 of 15 exoproteins from planktonic S. epidermidis significantly disrupted barrier integrity; however, biofilm exoproteins did not. The study also showed that some exoproteins from planktonic S. epidermidis significantly reduced cell viability, while exoproteins from planktonic and biofilm forms of S. lugdunensis and biofilm S. epidermidis did not induce any statistically significant change in cell viability. Notably, four of 16 biofilm exoproteins from S. lugdunensis induced higher interleukin‐6 (IL‐6) secretion, whereas none of the S. epidermidis isolates showed a significant increase in IL‐6 secretion.Our results suggest that CoNS exoproteins may contribute to CRS etiopathogenesis. [ABSTRACT FROM AUTHOR]

Despite the increasing morbidity and mortality associated with fungal diseases in low-income and sub-Saharan Africa countries, it is apparent that most of the fungal pathogens involved have been omitted from the dilated list of neglected and emerging tropical diseases (NETDs). Because most of these pathogens are inextricably linked with other underlying diseases such as tuberculosis and AIDS, the main fungal pathogens causing diseases viz. Pneumocyctosis and meningitis are categorized as deadly AIDS-associated opportunistic infections, and they most often coexist with tuberculosis. In addition, other infections like candidiasis, keratitis, histoplasmosis, and mycetoma often cause deforming and debilitating illnesses that affect the working class in rural communities, largely due to underlying comorbidities. Inadequate diagnostic tests prevent easy identification of the burden associated with these diseases making treatment very difficult. Likewise, the rise of resistance to most antifungal medications currently accessible in Africa is still extremely concerning, as observed in other locations. To expatiate on the destructive impact of fungal infections on the socioeconomic and health status of sub-Saharan Africa's skint populace and to improve the menace posed by these pathogens, there is a need to stop trivializing and underestimating fungal pathogens of health importance. This viewpoint is intended to revisit threats associated with neglected, emerging, and re-emerging fungal pathogens (NEFPs) in sub-Saharan Africa. As a result, information needed to prioritize strategies for the diagnosis, prevention, and control of neglected fungal pathogens and emerging superbugs will be presented. Revisiting threats and possible diagnoses associated with NEFPs could serve as a better leverage toward curbing the effects of opportunistic pathogens on individuals living with either an underlying health condition or impaired immunological status in sub-Saharan Africa/ low-income countries. Article Highlights: Structural presentation of deforming and debilitating illnesses associated with NEFPs. Reassessment of important therapeutic antibodies against NEFPs. Improved diagnostic methods for the diagnosis, prevention, and control of neglected fungal pathogens and emerging superbugs. [ABSTRACT FROM AUTHOR]

Chronic wounds and prosthetic joint infections are difficult to treat and are associated with a high burden of disease and economic cost. The rise of antibiotic resistance and the understanding of biofilm formation has inflamed an already challenging situation. Bacteriophage therapy has been used throughout the last century to treat bacterial infections. However, in the last 10 years, there has been a resurgence in phage therapy as a novel innovative treatment for nonhealing wounds. This mini systemic review assesses relevant clinical studies, case series and trials over 5 years associated with safety, treatment and success rates of phage therapy concerning nonhealing and prosthetic joint infections. A search of PubMed, Web of Science, Cochrane and Clinical Trials.gov databases resulted in 3151 studies, 27 met the criteria, and a total of 152 bacterial infections were treated from 130 individuals. Most common pathogen isolated in wounds was P. aeruginosa, and S. aureus was mostly associated with prosthetic joint infections. Treatment modalities differed across studies, adverse effects were limited, and success rate was deemed to be 91%. [ABSTRACT FROM AUTHOR]

Bacterial biofilms often lead to persistent infections because they provide a protective barrier and reproductive microenvironment for bacteria. Biofilms reduce the therapeutic effects of antibiotics and can easily lead to the emergence of multidrug‐resistant bacteria. Therefore, development of new materials for antibiofilm with synergistic effects is crucial. In this study, positively charged near‐infrared‐responsive nanoparticles (TDPPB) are synthesized to control the release and delivery of nitric oxide (NO) gas. A combination of NO and photothermal therapy (PTT) is used to enhance the antibiofilm performance of TDPPB. The positive charge of TDPPB induces the nanoparticles to adhere to the surface of the bacteria. Through 808 nm laser irradiation, the local high temperature triggers the efficient release of NO from the NO donor (BNN 6) in TDPPB. TDPPB integrates the release of NO, and PTT presents good antibiofilm activity against MRSA and Escherichia coli (E. coli) biofilms. TDPPB demonstrates excellent biosafety both in vivo and in vitro, shows good antibiofilm properties in biofilm‐infected mice, and promotes the healing of surface‐infected sites in vivo. Because of these advantages, TDPPB can be used as a potential therapeutic agent against biofilm infections in the biomedical field. [ABSTRACT FROM AUTHOR]

Historical cultural heritage sites are valuable for all of mankind, as they reflect the material and spiritual wealth of by nations, countries, or specific groups during the development of human civilization. The types and functions of microorganisms that form biofilms on the surfaces of architectural heritage sites influence measures to preserve and protect these sites. These microorganisms contribute to the biocorrosion of architectural heritage structures through the cycling of chemical elements. The ancient city wall of Shou County is a famous architectural and cultural heritage site from China's Song Dynasty, and the protection and study of this site have substantial historical and cultural significance. In this study, we used metagenomics to study the microbial diversity and taxonomic composition of the Song Dynasty city wall in Shou County, a tangible example of Chinese cultural heritage. The study covered three main topics: (1) examining the distribution of bacteria in the biofilm on the surfaces of the Song Dynasty city wall in Shou County; (2) predicting the influence of bacteria involved in the C, N, and S cycles on the corrosion of the city wall via functional gene analysis; and (3) discussing cultural heritage site protection measures for biocorrosion-related bacteria to investigate the impact of biocorrosion on the Song Dynasty city wall in Shou County, a tangible example of Chinese cultural heritage. The study revealed that (1) the biofilm bacteria mainly belonged to Proteobacteria, Actinobacteria, Cyanobacteria, Bacteroidetes, and Firmicutes, which accounted for more than 70% of the total bacteria in the biofilms. The proportion of fungi in the microbial community of the well-preserved city wall was greater than that in the damaged city wall. The proportion of archaea was low—less than 1%. (2) According to the Shannon diversity index, the well-preserved portion of the ancient city wall had the highest diversity of bacteria, fungi, and archaea, and bacterial diversity on the good city wall was greater than that on the corroded city wall. (3) Bray–Curtis distances revealed that the genomes of the two good city walls were similar and that the genomes of the corroded city wall portions were similar. Researchers also detected human intestine-related bacteria in four locations on the city walls, with the proportion of these bacteria in the microbial community being greater on good city walls than on bad city walls. (4) KEGG functional analysis revealed that the energy metabolism and inorganic ion transport activities of the bacterial community on the corroded city wall were greater than those of the good city wall. (5) In the carbon cycle, the absence of active glycolysis, the ED pathway, and the TCA cycle played significant roles in the collapse of the east city wall. (6) The nitrogen cycling processes involved ammonia oxidation and nitrite reduction to nitrate. (7) In the sulfur cycle, researchers discovered a crucial differential functional gene, SoxY, which facilitates the conversion of thiosulfate to sulfate. This study suggests that, in the future, biological approaches can be used to help cultural heritage site protectors achieve targeted and precise protection of cultural relics through the use of microbial growth inhibition technology. The results of this study serve as a guide for the protection of cultural heritage sites in other parts of China and provide a useful supplement to research on the protection of world cultural heritage or architectural heritage sites. [ABSTRACT FROM AUTHOR]

Background: Achillea fragrantissima (F. Asteraceae) is traditionally used to treat skin infections and inflammation. The present work intended to prepare essential oils (EOs) from A. fragrantissima aerial parts growing widely in Egypt and investigate its antibacterial activity against skin-related pathogens and in vitro cell-based anti-inflammatory activity. Methods: EOs of the fresh aerial parts were extracted by hydrodistillation (HD), microwave-assisted hydrodistillation (MAHD), and head-space (HS), while those of the dried ones were prepared by supercritical fluid (SF). The result EOs were analyzed using GC/MS. The antibacterial activity was evaluated alongside Pseudomonas aeruginosa ATCC 9027, Escherichia coli ATCC 8739, Staphylococcus aureus ATCC 25923, Streptococcus pyogenes ATCC 12344, Clostridium perfringens ATCC 13124 by agar diffusion, microwell dilution, and biofilm formation tests. The anti-inflammatory activity was evaluated by measuring tumor necrosis factor-alpha (TNF-α), interleukin 2 (IL-2), and 6 (IL-6) in lipopolysaccharides (LPS)- stimulated RAW 264.7 cells using ELISA assays in addition, expression of nitric oxide synthase (iNOS) was measured via western blot. Results: The SF method gave the highest EO yield (1.50 mL v/w). Oxygenated components constituted the highest percentage in the four methods, 84.14, 79.21, 73.29 and 33.57% in the HS, HD, MAHD, and SF, respectively. Moreover, variation in the amount of identified compounds was apparent; in HS EO α-thujone (29.37%), artemisia ketone (19.59%), and santolina alcohol (14.66%) are major components, while α-thujone (20.38%) and piperatone (12.09%) were significant in HD. Moreover, (+)-spathulenol (12.22%) and piperatone (10.48%) were significant in MAHD, while piperatone (14.83%) and β-sitosterol (11.07%) were significant in SF EO. HD, MAHD, and SF EOs exhibited susceptibility against P. aeruginosa (IZ = 9–14 mm), E. coli (11–13 mm), and C. perfringens (IZ = 10–14 mm) in agar diffusion assay. MAHD EOs demonstrated potent growth inhibition (MICs = 0.25–2 mg/mL), followed by HD EOs (MICs = 13–52 mg/mL) to all tested microorganisms in well microdilution assay. Also, they exert MBC values equal to or higher than the MICs. Furthermore, SF EOs inhibited the biofilm formation of all tested microorganisms by 65.12—80.84%. Specifically, MAHD and HD EOs efficiently suppress the biofilm of S. pyogenes (77.87%) and P. aeruginosa (60. 29%), respectively. Ultimately, HD and SF EOs showed anti-inflammatory activity by suppressing the TNF-α, IL-2, and IL-6 release and iNOS expression in LPS-stimulated RAW 264.7 macrophages. Conclusion: A. fragrantissima EO is rich in oxygenated volatile compounds with antibacterial and anti-inflammatory activities. It is encouraged as a bioactive agent for adjusting skin infections, though additional studies are essential for their safety in clinical settings. [ABSTRACT FROM AUTHOR]

Background: While the benefits of sonication for improving periprosthetic joint infection (PJI) are well-documented, its potential therapeutic effect against bacterial biofilm remains unstudied. This study aimed to investigate the safety and efficacy of a novel nanoparticle ultrasonication process on methicillin-resistant Staphylococcus aureus (MRSA) bacterial biofilm formation in a PJI rat model. Methods: This novel ultrasonication process was designed to remove attached bacterial biofilm from implant and peri-articular tissues, without damaging native tissues or compromising implant integrity. Twenty-five adult Sprague–Dawley rats underwent a surgical procedure and were colonized with intra-articular MRSA, followed by the insertion of a titanium screw. Three weeks after the index surgery, the animals received a second procedure during which the screws were explanted, and soft tissue was sampled. The intraoperative use of the nanoparticle sonication treatment was employed to assess the device's safety, while ex vivo treatment on the retrieved tissue and implants was used to evaluate its efficacy. Results: Clinical and histological assessments did not indicate any macro- or micro-damage to the host tissue. Sonication of the retrieved tissues demonstrated an average bacterial removal of 2 × 103 CFU/mL and 1 × 104 CFU/gram of tissue. Compared to the standard-of-care group (n = 10), implants treated with sonication (n = 15) had significantly lower remaining bacteria, as indicated by crystal violet absorbance measurements (P = 0.012). Conclusions: This study suggests that nanoparticle sonication technology can successfully remove attached bacterial biofilms from explanted orthopedic hardware and the joint capsule, without negatively affecting native tissue. The study provides initial results supporting the potential of nanoparticle sonication as an adjuvant treatment option during a DAIR (debridement, antibiotics, and implant retention) procedure for PJI, paving the way for future clinical trials. [ABSTRACT FROM AUTHOR]

Campylobacter jejuni is a major cause of food- and water-borne bacterial infections in humans. A key factor helping bacteria to survive adverse environmental conditions is biofilm formation ability. Nonetheless, the molecular basis underlying biofilm formation by C. jejuni remains poorly understood. Around thirty genes involved in the regulation and dynamics of C. jejuni biofilm formation have been described so far. We applied random transposon mutagenesis to identify new biofilm-associated genes in C. jejuni strain 81–176. Of 1350 mutants, twenty-four had a decreased ability to produce biofilm compared to the wild-type strain. Some mutants contained insertions in genes previously reported to affect the biofilm formation process. The majority of identified genes encoded hypothetical proteins. In the library of EZ-Tn5 insertion mutants, we found the cydB gene associated with respiration that was not previously linked with biofilm formation in Campylobacter. To study the involvement of the cydB gene in biofilm formation, we constructed a non-marked deletion cydB mutant together with a complemented mutant. We found that the cydB deletion-mutant formed a weaker biofilm of loosely organized structure and lower volume than the parent strain. In the present study, we demonstrated the role of the cydB gene in biofilm formation by C. jejuni. [ABSTRACT FROM AUTHOR]

This study evaluated the antibiofilm efficacy of a calcium silicate-based intracanal medicament (Bio-C Temp) against Fusobacterium nucleatum (F. nucleatum). Dentin slices (n = 88) were inoculated with F. nucleatum biofilms and divided into experimental groups (n = 24 each) treated with Bio-C Temp, triple antibiotic paste (TAP), or Ca(OH)2 for 1 or 2 weeks. Untreated dentin slices exposed to saline served as a positive control, while sterile dentin slices incubated anaerobically served as a negative control. Bacterial viability was assessed using confocal laser scanning microscopy after staining with LIVE/DEAD®BacLight™ dye. Samples treated with TAP demonstrated the highest percentage of dead bacteria (95%). The antibiofilm effect of TAP and Bio-C Temp significantly increased from Week 1 to Week 2. At Week 2, samples treated with Bio-C Temp showed a significantly higher percentage of dead bacteria (75.25%) than those treated with Ca(OH)2 (58.65%). TAP showed superior efficacy against F. nucleatum biofilms. After an application time of 2 weeks, the antibiofilm efficacy of Bio-C Temp was superior to that of Ca(OH)2. [ABSTRACT FROM AUTHOR]

Gelling-fibre dressings have been found to be a rapid and effective tool for exudate management. Suprasorb Liquacel Pro is a soft, conformable non-woven dressing made from sodium carboxymethyl cellulose and strengthening cellulose fibres. When it comes into contact with wound exudate or blood, the absorbent dressing forms a gel, creating a moist wound environment. Cell debris and bacteria in the exudate are retained inside the fibre dressing and removed during the dressing change. The high vertical absorption of exudate into the fibre dressing protects the wound environment and the wound edge, thus supporting the healing process. Suprasorb Liquacel Ag has additional antimicrobial abilities with the inclusion of nanosilver technology, shown to be effective in killing bacteria and managing bioburden. [ABSTRACT FROM AUTHOR]

Background: Suprasorb Liquacel Pro (standard test dressing) and Suprasorb Liquacel Ag (test dressing with silver nanoparticles) are absorptive gelling-fibre dressings designed to manage wound exudate levels and promote moist wound healing, with the latter having additional antimicrobial properties. Aims: To assess the impact of the test dressing on healing, exudate levels and signs of infection. Methods: Patients with moderately-to-highly exuding hard-to-heal wounds of any type were dressed with the standard test dressing or the test dressing with silver nanoparticles if they showed covert or overt signs of local infection. Comparative data were collected at baseline and 4-week conclusion. Adverse events and patient and professional opinions were also reported and collated. Findings: There were 19 patients with lower-limb wounds of various types present for a mean of 26 months. At baseline, most wounds were deteriorating or static (68%), while at conclusion most were improving or healed (84%), with additional indicators of improved healing. The number of patients with moderate-to-high exudate levels decreased from 84% to 53%. The 15 patients using the test dressing with silver nanoparticles saw reductions in covert signs of infection from 93% to 80%, overt signs of infection from 33% to 13% and antibiotic use from 13% to 7%. Conclusions: On average, the test dressings were effective in managing and reducing the barriers to healing, including high exudate, infection and biofilm, and in restarting stalled healing. [ABSTRACT FROM AUTHOR]

Background: Fixed orthodontic appliances act as a niche for microbial growth and colonization. Coating orthodontic wires with antimicrobial silver nanoparticles (AgNPs) and nanocomposite was adopted in this study to augment the biological activity of these wires by increasing their antibacterial and antibiofilm properties and inhibiting bacterial infections that cause white spot lesions and lead to periodontal disease. Methods: Three concentrations of biologically synthesized AgNPs were used for coating NiTi wires. The shape, size, and charge of the AgNPs were determined. Six groups of 0.016 × 0.022-inch NiTi orthodontic wires, each with six wires, were used; and coated with AgNPs and nanocomposites. The antimicrobial and antibiofilm activities of these coated wires were tested against normal flora and multidrug-resistant bacteria (Gram-positive and Gram-negative bacterial isolates). The surface topography, roughness, elemental percentile, and ion release were characterized. Results: AgNPs and nanocomposite coated NiTi wires showed significant antimicrobial and antibiofilm activities. The chitosan-silver nanocomposite (CS-Ag) coated wires had the greatest bacterial growth inhibition against both Gram-positive and Gram-negative bacteria. The surface roughness of the coated wires was significantly reduced, impacting the surface topography and with recorded low Ni and Ag ion release rates. Conclusions: NiTi orthodontic wires coated with AgNPs, and nanocomposites have shown increased antimicrobial and antibiofilm activities, with decreased surface roughness, friction resistance and limited- metal ion release. [ABSTRACT FROM AUTHOR]

Biofilms are unique, multicellular life forms that challenge our understanding of the microbial functioning. The last decades of research on biofilms have allowed us to better understand their importance in the context of both health and various pathologies in the human body, although many knowledge gaps hindering their correct comprehension still exist. Biofilms are classically described as mushroom-shaped structures attached to the substrate; however, an increasing body of evidence shows that their morphology in clinical conditions may differ significantly from that classically presented. Although this may result partly from the unique physicochemical conditions within the host, the interaction between microbes and immune cells during development of a biofilm should not be underestimated. The current Opinion confronts the classical view on biofilms with the latest scientific research describing the vitality of interactions with immune cells as a modulator of the biofilm phenotype and behavior in clinical conditions. [ABSTRACT FROM AUTHOR]

Introduction Debridement plays a critical role in wound management. In addition to removing necrotic tissue, debridement can eliminate bacteria frequently harbored within the tissue. This study evaluated a novel debridement method that uses plasma-based radiofrequency technology to remove tissue and bacteria. Coblation is a technology that uses radiofrequency energy to excite the electrolytes in a conductive medium, such as saline, to create a precisely focused plasma. This plasma field contains highly energized particles that possess sufficient energy to break tissue molecular bonds, causing the tissue to dissolve at relatively low temperatures (typically 40 °C to 70 °C). Materials and Methods Eighteen deep dermal wounds measuring 22 mm × 22 mm × 3 mm deep were created on pigs. Wounds were inoculated with methicillin-resistant Staphylococcus aureus USA300 (MRSA USA300) in combination with shrapnel and then covered with a polyurethane dressing for 24 hours. Wounds were then randomly assigned to one of the 3 treatment groups: (1) Coblation, (2) surgical debridement, and (3) no debridement. Wounds were biopsied on days 0, 5, 9, and 12, and specimens were processed for MRSA counts using selective media. Statistical analysis was performed using IBM SPSS statistics 27 using one-way ANOVA. Results Comparison between coblation and surgical debridement showed a decrease in bacterial count in all assessment times. The lowest bacterial count in all assessment times was observed in wounds debrided with coblation showing a statistically significant (P  ≤ .05) decrease in more than 2 Log CFU/g on days 0, 5, and 9 compared to no debridement. On day 12, coblation-debrided wounds exhibited 6.10 ± 0.22 Log CFU/g, and this value represents 99.99% of reduction compared with non-debrided wounds (P  ≤ .05). More than 96% of reduction (P  ≤ .05) resulted in wounds treated with coblation compared with surgically debrided. Conclusions Reducing MRSA bacterial infection counts, especially of biofilm-associated organisms, in combination with shrapnel may have important clinical implications, especially for the military personnel. Further research into the use of this technology in wound management is warranted. [ABSTRACT FROM AUTHOR]

Aerobic vaginitis (AV) is a long-standing inflammatory disease that affects female patients. The use of antibiotics is a common means for AV treatment, but it will indiscriminately kill both pathogenic bacteria and beneficial strains, which easily causes vaginal dysbacteriosis and infection recurrence. Herein, we describe a bioinspired strategy for fabricating gelated cell sheet-supported lactobacillus biofilms (GCS-LBs) for AV treatment. Compared with common planktonic probiotic formulations, probiotic biofilms forming on a robust GCS exhibit enhanced stress tolerance and better colonization capacity in the mouse vagina. Moreover, DNA nanodevices are decorated on the GCS and dynamically report the microenvironment change of biofilms for timely evaluating bacterium activity, both in vitro and in vivo. Consequently, GCS-LBs are used for treating AV in an Escherichia coli-infected mouse model, which shows enhanced therapeutic efficacy compared with conventional antibiotic or lactobacillus monotherapy. Overall, the GCS-LB shows promise as a potent multifunctional tool to combat bacterial infection. [ABSTRACT FROM AUTHOR]

Background Candida albicans can form polymicrobial biofilms with other microorganisms, such as Pseudomonas aeruginosa , at infection sites. Objectives As biofilms are highly resistant to antibiotics there is a need for new antibiofilm agents that have unique targets and modes of action. Methods In this study the antibiofilm effects of two quorum-sensing molecules (QSMs), farnesol and tyrosol, were investigated alone and in combination with antibiotics (aztreonam, colistin, tobramycin) and antifungals (fluconazole, amphotericin B, caspofungin), against single- and dual-species biofilms of C. albicans and P. aeruginosa in in vitro and in vivo systems. Results It was observed that QSMs alone, especially farnesol, showed at least a 1-log reduction against preformed single- and dual-species biofilms of C. albicans and P. aeruginosa. Combination of QSMs with colistin or fluconazole was found to be effective against both single- and dual-species biofilms in vitro. Increased survival was observed in C. elegans when treated with colistin or fluconazole in combination with QSMs, compared with no treatment. Additionally, the QSMs and colistin and farnesol combinations effectively inhibited biofilm formation by C. albicans and P. aeruginosa on bronchial epithelial cells, and reduced IL-1β expression in lung bronchial epithelial cells. Conclusions There is a need for effective treatments for bacterial-fungal biofilm infections and, to our knowledge, there have been no studies of QSMs and antimicrobial combinations against dual-species biofilms involving C. albicans and P. aeruginosa. Hence these findings will make a significant contribution to the literature. [ABSTRACT FROM AUTHOR]

Key points: Novel topical therapeutics require extensive pre‐clinical testing to assess efficacy and safety.Antibiofilm or immunosuppressant agents can utilize ex vivo models to measure ciliotoxicity.Agents that are found to be effective and non‐toxic ex vivo warrant further investigation in vivo. [ABSTRACT FROM AUTHOR]

Stuccoes are very delicate decorative elements of Roman age. Very few of them survived almost intact to present days and, for this reason, they are of great interest to restorers and conservators. In this study, we combined metabarcoding and untargeted metabolomics to characterise the taxonomic and metabolic profiles of the microorganisms forming biofilms on the stuccoes located on the ceiling of the laconicum, a small thermal environment in the archaeological park of Baia (southern Italy). We found that some samples were dominated by bacteria while others by eukaryotes. Additionally, we observed high heterogeneity in the type and abundance of bacterial taxa, while the eukaryotic communities, except in one sample (at prevalence of fungi), were dominated by green algae. The metabolic profiles were comparable across samples, with lipids, lipid-like molecules and carbohydrates accounting for roughly the 50% of metabolites. In vitro and in vivo tests to remove biofilms on stuccoes using essential oils blends were successful at a 50% dilution for one hour and half. This integrative study advanced our knowledge on taxonomic and metabolic profiles of biofilms on ancient stuccoes and highlighted the potential impacts of these techniques in the field of cultural heritage conservation. [ABSTRACT FROM AUTHOR]

Clostridioides difficile is a Gram-positive, spore-forming, rod-shaped, obligate anaerobe that is the leading cause of antibiotic-associated diarrhea. Type IV pili (T4P) are elongated appendages on the surface of C. difficile that are polymerized from many pilin proteins. T4P play an important role in C. difficile adherence and particularly in its persistence in the host intestine. Recent studies have shown that T4P promote C. difficile aggregation, surface motility, and biofilm formation, which may enhance its pathogenicity. Additionally, the second messenger cyclic diguanylate increases pilA1 transcript abundance, indirectly promoting T4P-mediated aggregation, surface motility, and biofilm formation of C. difficile. This review summarizes recent advances in C. difficile T4P research and the physiological activities of T4P in the context of C. difficile pathogenesis. [ABSTRACT FROM AUTHOR]

Bacterial cells often exist in the form of sessile aggregates known as biofilms, which are polymicrobial in nature and can produce slimy Extracellular Polymeric Substances (EPS). EPS is often referred to as a biofilm matrix and is a heterogeneous mixture of various biomolecules such as polysaccharides, proteins, and extracellular DNA/RNA (eDNA/RNA). In addition, bacteriophage (phage) was also found to be an integral component of the matrix and can serve as a protective barrier. In recent years, the roles of proteins, polysaccharides, and phages in the virulence of biofilms have been well studied. However, a mechanistic understanding of the release of such biomolecules and their interactions with antimicrobials requires a thorough review. Therefore, this article critically reviews the various mechanisms of release of matrix polymers. In addition, this article also provides a contemporary understanding of interactions between various biomolecules to protect biofilms against antimicrobials. In summary, this article will provide a thorough understanding of the functions of various biofilm matrix molecules. [ABSTRACT FROM AUTHOR]

Objective: To analyze if the microbiome community composition in primary endodontic infections is associated with clinical or radiographic factors. Materials and methods: Seventy-one patients with primary endodontic infections were evaluated for percussion tenderness, presence of a sinus tract, presence of caries, sex, probing depth > 4 mm, and age. Samples from the root canals were obtained and the microbiome was subsequently characterized by 16 S rRNA amplicon sequencing. For the radiographic analysis, a subset of 12 samples with a periapical index (PAI) ≤ 2 were compared with 19 samples with PAI of 5. The Shannon and Chao1 indices were used to measure alpha diversity. Differences in abundances of genera were evaluated using the Kruskal-Wallis test with Bonferroni’s correction. Differences in community composition were evaluated using analysis of similarity (ANOSIM) with Bray-Curtis dissimilarity matrices. Results: No significant differences in microbiome composition relative to clinical factors were found using ANOSIM. Teeth within the two categories of periapical index showed a similar number of species richness, and alpha diversity values P > 0.05. Community composition was significantly affected by the periapical index (ANOSIM P = 0.039, R = 0.10). Larger radiographic lesions demonstrated significant increase in Prevotellaceae, Olsenella, and the motile bacteria Oribacterium, Selenomonadaceae spp., and Treponema. Conclusion: Clinical factors associated with apical periodontitis have a limited impact on the root canal microbiome composition. Community composition appears to be affected in teeth with large apical lesions. [ABSTRACT FROM AUTHOR]

We provide a brief review of the development and application of the Mesolens and its impact on microbiology. Microbial specimens such as infected tissue samples, colonies surfaces, and biofilms are routinely collected at the mesoscale. This means that they are relatively large multimillimetre‐sized samples which contain microscopic detail that must be observed to answer important questions across various sectors. The Mesolens presents the ideal imaging method to study these specimens as no other optical microscope can thanks to its unique combination of low magnification and high numerical aperture providing large field‐of‐view, high‐resolution imaging. We demonstrate the current applications of the Mesolens to microbial imaging and go on to outline the huge potential of the Mesolens to impact other key areas of microbiology. [ABSTRACT FROM AUTHOR]

The objective of this study was to compare the microbial adhesion of different oral pathogens on different wires used in orthodontic treatment and to evaluate the potential of these pathogens to form biofilms on different types of orthodontic wires and brackets. In this in vitro investigation, we calculated that the sample size for each group (i.e., those with brackets [metal braces, ceramic braces, and self-ligating braces] and wires [nickel titanium, titanium molybdenum, and stainless steel]) should be 15 individuals. Five types of microbes (Streptococcus mutans , Escherichia coli , Enterococcus faecalis , Staphylococcus aureus , and Candida albicans) were used. Three types of brackets and three types of wires were used with five types of bacteria, and the process was repeated three times to collect the average. No significant differences were observed in the mean concentrations of bacteria in the different brackets (p > 0.05) or in the mean concentrations in the different orthodontic materials used in these brackets. In contrast, there were considerable differences between the concentrations of bacteria in the wires and those in the brackets (p < 0.05). Different wires and brackets have different associations with bacterial adhesion and concentration. The wires exhibited more substantial biofilm absorbance and concentrations than the brackets. The adhesion of biofilm may be a decisive factor when choosing a type of orthodontic wire, particularly for individuals at high risk of developing bacterial oral diseases, such as periodontal diseases and dental caries. [ABSTRACT FROM AUTHOR]

The fungi and bacteria on the human scalp play important roles in both health and disease. Scalp biofilms have pathogenic effects on cutaneous tissues, such as seborrheic dermatitis. However, investigations into scalp biofilms and their physiological effects on scalp skin are limited. In this study, we suggest an evaluation method through which the scalp is stained a reddish color using erythrosine to visualize scalp biofilms, which strongly depends on the presence of bacteria and fungi. We found that the physiological properties of the scalp significantly differed between high and low levels of stained red areas (sRAs) on the scalp. The sRA levels showed a strong positive correlation with IL-8 levels and sebum production. It is worth noting that the production of sebum has a dominant effect on the scalp microbiome via the growth of microbes, leading to the formation of a biofilm, as evidenced by changes in the sRA levels. Furthermore, the sRA levels could be reduced through the use of antimicrobial agents, such as climbazole and hexamidine diisethionate (HD), as well as the manipulation of the physical properties of the scrubs used in scalp care products. These scalp care products could potentially disrupt the formation and accumulation of a biofilm on the scalp, providing strong evidence for the importance of considering the scalp microbiome and its interactions with sebum in the development of biofilms. Consequently, we suggested that the administration of anti-microbial agents, such as climbazole and HD, could be an effective strategy to alleviate biofilm accumulation for the maintenance of scalp health. [ABSTRACT FROM AUTHOR]

This study aimed to explore the mechanism by which phenethyl isothiocyanate (PEITC) inhibited the adhesion and biofilm formation of Staphylococcus aureus (S. aureus). PEITC exhibited antimicrobial efficacy against S. aureus, demonstrating a minimum inhibition concentration (MIC) of 1 mmol/L. PEITC exerted its antibacterial effect by disrupting cell membrane integrity, and it decreased total adenosine triphosphate (ATP) production after 1 and 4 h treatment. PEITC at 0.5 mmol/L increased the level of intracellular reactive oxygen species (ROS) by 26.39% compared to control. The mature biofilm of S. aureus was destroyed by 86.4% after treatment with PEITC for 24 h. Adhesion tests revealed that PEITC at 0.5 mmol/L reduced 44.51% of the S. aureus that adhered to NCM460 cells. Furthermore, at the genetic level, PEITC significantly downregulated the related genes by 31.26% to 97.04%, including agrB, agrD, isdA, ebh, luxS, fnbA, and icaR. Moreover, PEITC markedly inhibited S. aureus proliferation in beef preserved at temperatures of 25 and 4 °C, respectively. In summary, the present study suggests that PEITC effectively inhibits the adhesion and biofilm formation of S. aureus by affecting the relevant genes of S. aureus and holds promise for microbial management in meat products. [ABSTRACT FROM AUTHOR]