Bacterial killing and the dimensions of bacterial death.

Bacteria can be dead, alive, or exhibit slowed or suspended life forms, making bacterial death difficult to establish. Here, agar-plating, microscopic-counting, SYTO9/propidium-iodide staining, MTT-conversion, and bioluminescence-imaging were used to determine bacterial death upon exposure to different conditions. Rank correlations between pairs of assay outcomes were low, indicating different assays measure different aspects of bacterial death.

Ellagic acid-modified gold nanoparticles to combat multi-drug resistant bacterial infections and .

The overuse of antibiotics has led to the rapid development of multi-drug resistant bacteria, making antibiotics increasingly ineffective against bacterial infections. Consequently, there is an urgent need to develop alternative strategies to combat multi-drug-resistant bacterial infections. In this study, gold nanoparticles modified with ellagic acid (EA-AuNPs) were prepared using a simple and mild one-pot hydrothermal process.

Nano-architectonics of Pt single-atoms and differently-sized nanoparticles supported by manganese-oxide nanosheets and impact on catalytic and anti-biofilm activities.

Hybrid-nanozymes are promising in various applications, but comprehensive comparison of hybrid-nanozymes composed of single-atoms or nanoparticles on the same support has never been made. Here, manganese-oxide nanosheets were loaded with Pt-single-atoms or differently-sized nanoparticles and their oxidase- and-peroxidase activities compared. High-resolution Transmission-Electron-Microscopy and corresponding Fast Fourier Transform imaging showed that Pt-nanoparticles (1.

Cetyltrimethylammonium-chloride assisted in situ metabolic incorporation of nano-sized ROS-generating cascade-reaction containers in Gram-positive and Gram-negative peptidoglycan layers for the control of bacterially-induced sepsis.

Cascade-reaction containers generating reactive oxygen species (ROS) as an alternative for antibiotic-based strategies for bacterial infection control, require endogenous oxygen-sources and ROS-generation close to or preferably inside target bacteria. Here, this is achieved by cetyltrimethylammonium-chloride (CTAC) assisted in situ metabolic labeling and incorporation of mesoporous SiO-nanoparticles, dual-loaded with glucose-oxidase and FeO-nanoparticles as cascade-reaction containers, inside bacterial cell walls. First, azide-functionalized d-alanine (D-Ala-N) was inserted in cell wall peptidoglycan layers of growing Gram-positive pathogens.

A normalized parameter for comparison of biofilm dispersants .

Dispersal of infectious biofilms increases bacterial concentrations in blood. To prevent sepsis, the strength of a dispersant should be limited to allow the immune system to remove dispersed bacteria from blood, preferably without antibiotic administration. Biofilm bacteria are held together by extracellular polymeric substances that can be degraded by dispersants.

Lethal puncturing of planktonic Gram-positive and Gram-negative bacteria by magnetically-rotated silica hexapods.

Planktonic bacterial presence in many industrial and environmental applications and personal health-care products is generally countered using antimicrobials. However, antimicrobial chemicals present an environmental threat, while emerging resistance reduces their efficacy. Suspended bacteria have no defense against mechanical attack.

Maintaining sidedness and fluidity in cell membrane coatings supported on nano-particulate and planar surfaces.

Supported cell membrane coatings meet many requirements set to bioactive nanocarriers and materials, provided sidedness and fluidity of the natural membrane are maintained upon coating. However, the properties of a support-surface responsible for maintaining correct sidedness and fluidity are unknown. Here, we briefly review the properties of natural membranes and membrane-isolation methods, with focus on the asymmetric distribution of functional groups in natural membranes (sidedness) and the ability of molecules to float across a membrane to form functional domains (fluidity).

Ciprofloxacin-Loaded, pH-Responsive PAMAM-Megamers Functionalized with S-Nitrosylated Hyaluronic Acid Support Infected Wound Healing in Mice without Inducing Antibiotic Resistance.

Antimicrobial-resistant bacterial infections threaten to become the number one cause of death by the year 2050. Since the speed at which antimicrobial-resistance develops is exceeding the pace at which new antimicrobials come to the market, this threat cannot be countered by making more, new and stronger antimicrobials. Promising new antimicrobials should not only kill antimicrobial-resistant bacteria, but also prevent development of new bacterial resistance mechanisms in strains still susceptible.

Magnetically-targetable outer-membrane vesicles for sonodynamic eradication of antibiotic-tolerant bacteria in bacterial meningitis.

Treatment of acute bacterial meningitis is difficult due to the impermeability of the blood-brain barrier, greatly limiting the antibiotic concentrations that can be achieved in the brain. Escherichia coli grown in presence of iron-oxide magnetic nanoparticles secrete large amounts of magnetic outer-membrane vesicles (OMVs) in order to remove excess Fe from their cytoplasm. OMVs are fully biomimetic nanocarriers, but can be inflammatory.

Rapid Bacterial Detection and Gram-Identification Using Bacterially Activated, Macrophage-Membrane-Coated Nanowired-Si Surfaces in a Microfluidic Device.

Bacterially induced sepsis requires rapid bacterial detection and identification. Hours count for critically ill septic patients, while current culture-based detection requires at least 10 h up to several days. Here, we apply a microfluidic device equipped with a bacterially activated, macrophage-membrane-coating on nanowired-Si adsorbent surfaces for rapid, bacterial detection and Gram-identification in bacterially contaminated blood.

Nanogel-based coating as an alternative strategy for biofilm control in drinking water distribution systems.

Biofilm formation and detachment in drinking water distribution systems (DWDS) can lead to several operational issues. Here, an alternative biofilm control strategy of limiting bacterial adhesion by application of a poly(-isopropylmethacrylamide)-based nanogel coating on DWDS pipe walls was investigated. The nanogel coatings were successfully deposited on surfaces of four polymeric pipe materials commonly applied in DWDS construction.

Zwitterionic poly(sulfobetaine methacrylate)-based hydrogel coating for drinking water distribution systems to inhibit adhesion of waterborne bacteria.

Presence of biofilms in drinking water distribution systems (DWDS) can be a nuisance, leading to several operational and maintenance issues (i.e., increased secondary disinfectants demand, pipe damage or increased flow resistance), and so far, no single control practice was found to be sufficiently effective.

Identification of Potential Antimicrobial Targets of Pseudomonas aeruginosa Biofilms through a Novel Screening Approach.

Pseudomonas aeruginosa is an opportunistic pathogen of considerable medical importance, owing to its pronounced antibiotic tolerance and association with cystic fibrosis and other life-threatening diseases. The aim of this study was to highlight the genes responsible for P. aeruginosa biofilm tolerance to antibiotics and thereby identify potential new targets for the development of drugs against biofilm-related infections.

A Heterocatalytic Metal-Organic Framework to Stimulate Dispersal and Macrophage Combat with Infectious Biofilms.

Eradication of infectious biofilms is becoming increasingly difficult due to the growing number of antibiotic-resistant strains. This necessitates development of nonantibiotic-based, antimicrobial approaches. To this end, we designed a heterocatalytic metal-organic framework composed of zirconium 1,4-dicarboxybenzene (UiO-66) with immobilized Pt nanoparticles (Pt-NP/UiO-66).

A dynamic flow model mimicking duodenoscope reprocessing after bacterial contamination for translational research.

Objective: Duodenoscopy-associated infections and outbreaks are reported globally despite strict adherence to duodenoscope reprocessing protocols. Therefore, new developments in the reprocessing procedure are needed.

Design: We evaluated a novel dynamic flow model for an additional cleaning step between precleaning and manual cleaning in the reprocessing procedure.

Proton-mediated burst of dual-drug loaded liposomes for biofilm dispersal and bacterial killing.

Exposure of infectious biofilms to dispersants induces high bacterial concentrations in blood that may cause sepsis. Preventing sepsis requires simultaneous biofilm dispersal and bacterial killing. Here, self-targeting DCPA(2-(4-((1,5-bis(octadecenoyl)1,5-dioxopentan-2-yl)carbamoyl)pyridin-1-ium-1-yl)acetate) liposomes with complexed water were self-assembled with ciprofloxacin loaded in-membrane and PEGylated as a lipid-membrane component, together with bromelain loaded in-core.

Synergy between pH- and hypoxia-responsiveness in antibiotic-loaded micelles for eradicating mature, infectious biofilms.

Antibiotic-loaded PEG/PAE-based micelles are frequently considered for eradicating infectious biofilms. At physiological pH, PEG facilitates transport through blood. Near an acidic infection-site, PAE becomes protonated causing micellar targeting to a biofilm.

Viscoelastic properties of plasma-agarose hydrogels dictate favorable fibroblast responses for skin tissue engineering applications.

Dermal wound healing relies on the properties of the extracellular matrix (ECM). Thus, hydrogels that replicate skin ECM have reached clinical application. After a dermal injury, a transient, biodegradable fibrin clot is instrumental in wound healing.

A Comparison of the Adaptive Response of vs. and the Development of Chlorhexidine Resistance.

Antimicrobials with nonselective antibacterial efficacy such as chlorhexidine can be effective in reducing biofilm, but bear the risk of inducing resistance in specific bacteria. In clinical practice, bacteria such as have been found resistant to chlorhexidine, but other bacteria, including , have largely remained susceptible to chlorhexidine despite its widespread use in oral healthcare. Here, we aim to forward a possible reason as to why can acquire resistance against chlorhexidine, while remains susceptible to chlorhexidine.

A self-cleaning surface based on UV-activatable, AgCl micropumps for bacterial killing and removal.

We report a self-cleaning, bacterial killing surface by immobilization of AgCl microparticles on a surface, acting as chemical micropumps. The surface shows a high bacterial killing efficacy of attached bacteria and exhibits sustainable removal of bacteria as a result of UV-activatable micropumping originating from the photocatalytic reaction of AgCl microparticles. Our work provides an advance in the sustainable use of bacterial contact-killing surfaces through removal of dead bacteria and debris that may shield contact-killing sites.