Antibacterial Therapy Research Articles

Vitamin B6 appended polypyridyl Co(III) complexes for photo-triggered antibacterial activity.

Three novel polypyridyl-Co(III)-vitamin B6 complexes viz., [Co(CF3-phtpy)(SBVB6)]Cl (Co1), [Co(anthracene-tpy)(SBVB6)]Cl (Co2), [Co(NMe2-phtpy)(SBVB6)]Cl (Co3), where 4'-(4-(trifluoromethyl)phenyl)-2,2':6',2''-terpyridine = CF3-phtpy, 4'-(anthracen-9-yl)-2,2':6',2''-terpyridine = anthracene-tpy;, 4-([2,2':6',2''-terpyridin]-4'-yl)-N,N-dimethylaniline = NMe2-phtpy, (E)-5-(hydroxymethyl)-4-(((2-hydroxyphenyl)imino)methyl)-2-methylpyridin-3-ol = H2SBVB6 was successfully developed for aPDT (antibacterial photodynamic therapy) applications. Co1-Co3 exhibited an intense absorption band at ca. 435-485 nm, which is attributed to ligand-to-metal charge transfer and was beneficial for antibacterial photodynamic therapy. The distorted octahedral geometry of the complexes with CoIIIN4O2 core was evident from the DFT study. The visible light absorption ability and good photo-stability of Co1-Co3 made them good photosensitizers for aPDT. Co1-Co3 displayed significant antibacterial responses against gram-positive (S. aureus) and gram-negative (E. coli) bacteria upon light exposure (10 J cm-2, 400-700 nm) and showed MIC values between 0.01-0.005 µg mL-1. The aPDT activities of these complexes were due to their ability to damage bacterial cell membranes via ROS generation. Overall, this study shows the photo-triggered ROS-mediated bacteria-killing potential of Co(III) complexes.

The Use of Online Platforms Amrmap and Amrbook in Teaching Medical Students

The authors describe the functional capabilities of the online platforms AMRmap and AMRbook. The use of the platforms clearly demonstrates the depth and danger of the problem of increasing antibacterial resistance and allows you to avoid making mistakes when selecting antibacterial therapy. These platforms are convenient web products for visualizing educational material, capable of immersing a medical student in the space of his future professional activity. According to the authors, active learning methods using the AMRmap and AMRbook platforms increase motivation and assimilation of educational material by students.

Ultra-Photostable Bacterial-Seeking Near-Infrared CPDs for Simultaneous NIR-II Bioimaging and Antibacterial Therapy.

Bacterial infections can pose significant health risks as they have the potential to cause a range of illnesses. These infections can spread rapidly and lead to complications if not promptly diagnosed and treated. Therefore, it is of great significance to develop a probe to selectively target and image pathogenic bacteria while simultaneously killing them, as there are currently no effective clinical solutions available. This study presents a novel approach using near-infrared carbonized polymer dots (NIR-CPDs) for simultaneous in vivo imaging and treatment of bacterial infections. The core-shell structure of the NIR-CPDs facilitates their incorporation into bacterial cell membranes, leading to an increase in fluorescence brightness and photostability. Significantly, the NIR-CPDs exhibit selective bacterial-targeting properties, specifically identifying Staphylococcus aureus (S.aureus)while sparing Escherichia coli (E. coli). Moreover, under 808nm laser irradiation, the NIR-CPDs exhibit potent photodynamic effects by generating reactive oxygen species that target and damage bacterial membranes. In vivo experiments on infected mouse models demonstrate not only precise imaging capabilities but also significant therapeutic efficacy, with marked improvements in wound healing. The study provides the dual-functional potential of NIR-CPDs as a highly effective tool for the advancement of medical diagnostics and therapeutics in the fight against bacterial infections.

Copper tannate nanosheets-embedded multifunctional coating for antifouling and photothermal bactericidal applications

Implant-associated infections (IAIs), triggered by pathogenic bacteria, are a leading cause of implant failure. The design of functionalized coatings on biomedical materials is crucial to address IAIs. Herein, a multifunctional coating with good antifouling effect and antibacterial photothermal therapy (aPTT) performance was developed. The copper tannate nanosheets (CuTA NSs) were formed via coordination bonding of Cu2+ ions and tannic acid (TA). The CuTA NSs were then integrated into the TA and poly(ethylene glycol) (PEG) network to form the TCP coating for deposition on the titanium (Ti) substrates via surface adhesion of TA and gravitational effect. The resulting Ti-TCP substrate exhibited good antifouling property, reactive oxygen species (ROS) scavenging capability and cytocompatibility. The TCP coating exhibited antifouling efficacy in conjunction with aPTT, curtailing the surface adhesion and biofilm formation of pathogens, such as Staphylococcus aureus and Escherichia coli. Notably, the Ti-TCP substrate also exhibited the ability to prevent bacterial infection in vivo in a subcutaneous implantation model. The present work demonstrated a promising approach in designing high-performance antifouling and photothermal bactericidal coatings to combat IAIs.

Intelligent Carbon Dots with Switchable Photo-Activated Oxidase-Mimicking Activity and pH Responsive Antioxidant Activity Adaptive to the Wound Microenvironment for Selective Antibacterial Therapy.

Intelligent antibacterial agent with controllable activities adaptive to the wound microenvironment is appealing to reduce drug resistance and enhance antibacterial efficiency. In this study, celery is chosen as the carbon source to construct celery-based carbon dots (CECDs) with double activities, i.e., reactive oxygen species (ROS)-production and ROS-clearance activities. The ROS-production capability of CECDs is dependent on the oxidase (OXD)-mimicking activity, which is only photo-activated and thus artificially controlled by light to avoid the production of excess ROS. Meanwhile, the optimal OXD-mimicking activity occurrs at the pH of 5, close to microenvironmental pH at the bacterial infection site, which will enhance the antibacterial efficacy. On the other hand, CECDs exhibit the antioxidant activity at the neutral or weak alkaline pH, which will assist the healing of the wound. Thus, the conversion of ROS-production and ROS-clearance ability of CECDs can be dynamically and intelligently switched automatically with microenvironmental pH at different stages of treatment (from acid to neutral/weak basic). The proposed CECDs exert adorable selective antibacterial activity against Gram-positive bacteria and satisfactory therapeutic effect on bacteria infected mice. This study paves a new avenue to design the intelligent antibacterial nanoagent sensitive to the infected microenvironmental condition, reducing drug resistance and assisting precise medicine.

Enhanced antibacterial photodynamic therapy with Qu/Ce6@ZIF-8 nanoplatform for Staphylococcus aureus control in food preservation

Antimicrobial Photodynamic Therapy (aPDT) effectively combats Staphylococcus aureus (S. aureus) infections and mitigates antibiotic resistance. However, the application of aPDT is constrained by challenges related to photosensitizers, such as poor water solubility, a tendency to aggregate, and low bioavailability. In response, we have developed a nanoplatform using ZIF-8 nanocomposites. Through in-situ synthesis, we incorporated the chlorin e6 (Ce6) into the ZIF-8 matrix based on competitive coordination strategy, significantly enhancing its photocatalytic activity. The bioactivity of quercetin (Qu), through competitive inhibition of Sortase A (SrtA), enhances bacterial cell membrane permeability, thereby boosting the efficacy of the Qu/Ce6@ZIF-8 nanoparticles. This dual antibacterial strategy markedly suppresses S. aureus growth (MIC = 150 μg/mL). Moreover, we have engineered a polycaprolactone (PCL) composite film embedding these nanoparticles, which, under red light irradiation, substantially inhibits S. aureus proliferation on chilled chicken surfaces, thus extending shelf life to eight days. This innovative approach offers a promising strategy for antimicrobial food preservation, employing a multifunctional nano-antibacterial platform.

Natural medicine can substitute antibiotics in animal husbandry: protective effects and mechanisms of rosewood essential oil against Salmonella infection

Aniba rosaeodora essential oil (RO) has been traditionally used in natural medicine as a substitute for antibiotics due to its notable antidepressant and antibacterial properties. Salmonella, a prevalent pathogen in foodborne illnesses, presents a major challenge to current antibiotic treatments. However, the antibacterial efficacy and mechanisms of action of RO against Salmonella spp. remain underexplored. This study aims to elucidate the chemical composition of RO, evaluate its antibacterial activity and mechanisms against Salmonella in vitro, and further delineate its anti-inflammatory mechanisms in vivo during Salmonella infection. Gas chromatography-mass spectrometry (GC-MS) was utilized to characterize the chemical constituents of RO. The antibacterial activity of RO was assessed using minimal inhibitory concentration (MIC) and time-kill assays. Various biochemical assays were employed to uncover the potential bactericidal mechanisms. Additionally, mouse and chick models of Salmonella infection were established to investigate the prophylactic effects of RO treatment. RO exhibited significant antibacterial activity against both Gram-positive and Gram-negative bacteria, with an MIC of 4 mg·mL−1 for Salmonella spp. RO treatment resulted in bacterial damage through the disruption of lipid and purine metabolism. Moreover, RO reduced injury and microbial colonization in infected mice and chicks. RO treatment also modulated the host inflammatory response by inhibiting proinflammatory pathways. In conclusion, our findings demonstrate that RO is effective against Salmonella infection, highlighting its potential as an alternative to antibiotics for antibacterial therapy.

Low‐cost 0D and 2D carbon material co‐decorated titanium dioxide ternary heterojunction for rapid and efficient bacteria killing under visible light

AbstractRecently, the issue of bacterial resistance has gotten worse because of the overuse of antibiotics. The newborn superbacteria, such as vancomycin‐resistant bacteria, were hard to kill, inspiring researchers to find new ways to kill the bacteria efficiently. TiO2 was used as an efficient photocatalyst for water splitting and pollutant degradation. However, the weak efficiency limited the application to solve the drug‐resistance problem. Consequently, the incorporation of low‐cost 0D carbon quantum dots (CQDs) and 2D graphene oxide (GO) was pursued to amplify the visible light absorption capabilities of TiO2 and thereby elevate its photocatalytic activity. After forming the heterogeneous interface of CQDs and TiO2, CQDs converted part of visible light into wavelength less than 400 nm using the up‐conversion property. The modification of CQDs enabled electrons to be easily transferred from the conduction band of CQDs to the conduction band of TiO2. Meanwhile, GO can act as an electron acceptor, reduce the recombination efficiency of holes and electrons, and transfer the photogenerated electrons in the redox reaction in the heterogeneous interface. Because of the excellent absorption of GO, TiO2/CQDs/GO reached 57.8°C after 20 min irradiation under 1.5 times sunlight, which provided a prerequisite for photodynamic antibacterial therapy/photothermal antibacterial therapy synergistic antibacterial potential. TiO2/CQDs/GO possessed an antibacterial efficiency as high as 99.3% toward Staphylococcus aureus which has a bright future in disinfection in vivo and medical devices as well as water sterilization.

Nitrite reductase-mimicking catalysis temporally regulating nitric oxide concentration gradient adaptive for antibacterial therapy.

The unique bacterial infection microenvironment (IME) usually requires complicated design of nanomaterials to adapt to IME for enhancing antibacterial therapy. Here, an alternative IME adaptative nitrite reductase-mimicking nanozyme is constructed by in situ growth of ultrasmall copper sulfide clusters on the surface of a nanofibrillar lysozyme assembly (NFLA/CuS NHs), which can temporally regulate nitric oxide (NO) gradient concentration to kill bacteria initially and promote tissue regeneration subsequently. Benefiting from a copper nitrite reductase (CuNIR)-inspired structure with CuS cluster as active center and NFLA as skeleton, NFLA/CuS NHs efficiently boost the catalytic reduction of nitrite to NO. The inherent supramolecular fibrillar networks displays excellent bacterial capture capability, facilitating initial high-concentration NO attacks on the bacteria. The subsequent catalytic release of low-concentration NO by NFLA/CuS NHs-mediated nitrite reduction remarkably promotes cell migration and angiogenesis. This work paves the way for dynamically eliminating MDR bacterial infection and promoting tissue regeneration in a simple and smart way through CuNIR-mimicking catalysis.

NIR responsive scaffold with multistep shape memory and photothermal-chemodynamic properties for complex tissue defects repair and antibacterial therapy

Complex tissue damage accompanying with bacterial infection challenges healthcare systems globally. Conventional tissue engineering scaffolds normally generate secondary implantation trauma, mismatched regeneration and infection risks. Herein, we developed an easily implanted scaffold with multistep shape memory and photothermal-chemodynamic properties to exactly match repair requirements of each part from the tissue defect by adjusting its morphology as needed meanwhile inhibiting bacterial infection on demand. Specifically, a thermal-induced shape memory scaffold was prepared using hydroxyethyl methacrylate and polyethylene glycol diacrylate, which was further combined with the photothermal agent iron tannate (FeTA) to produce NIR light-induced shape memory property. By varying ingredients ratios in each segment, this scaffold could perform a stepwise recovery under different NIR periods. This process facilitated implantation after shape fixing to avoid trauma caused by conventional methods and gradually filled irregular defects under NIR to perform suitable tissue regeneration. Moreover, FeTA also catalyzed Fenton reaction at bacterial infections with abundant H2O2, which produced excess ROS for chemodynamic antibacterial therapy. As expected, bacteriostatic rate was further enhanced by additional photothermal therapy under NIR. The in vitro and vivo results showed that our scaffold was able to perform high efficacy in both antibiosis, inflammation reduction and wound healing acceleration, indicating a promising candidate for the regeneration of complex tissue damage with bacterial infection.

КЛИНИКО-ЭПИДЕМИОЛОГИЧЕСКИЕ ОСОБЕННОСТИ БОЛЕЗНИ ЛАЙМА В НОВГОРОДСКОЙ ОБЛАСТИ

Lyme disease is the most common vector-borne disease of the forest zone of the Northern hemisphere of the planet, which is characterized by polymorphism of clinical forms of the infectious process. The polysystemic nature of lesions, the complexity of specific diagnosis and the lack of information to the public and primary care physicians make it difficult to verify the diagnosis and often lead to late diagnosis and the development of irreversible functional disorders. The aim of the study is to study the clinical and epidemiological features of Lyme disease in the Novgorod region. Materials and methods. A retrospective analysis of the epidemic situation in the morbidity of the population of the Novgorod region and a retrospective analysis of the medical histories of hospitalized patients diagnosed with Lyme disease in the Novgorod Regional Infectious Diseases Hospital for the period 2013-2023 were carried out. The results obtained. The high incidence of Lyme disease in the Novgorod region determines a special wariness towards this disease. The number of ticks in nature increases annually (the average number of ticks in nature in 2023 was 1,9 ex/km, and in 2013 – 1,2 ex/km), which is directly related to an increase in the average climatic temperature. Lyme disease is a seasonal disease, and people of retirement age are most often infected. In 90% of cases, patients do not know about the danger of this disease, the possibility of its transition to a chronic form and do not go to medical institutions for specific emergency prevention. The most vulnerable places of tick suction are the abdomen and the inner surface of the shoulder. According to the clinical picture, the erythemic form of the disease prevailed (70,7%), the febrile form (20,3%) and the meningeal form (8,98%) were less common. The majority of patients are admitted to the hospital with early manifestations of the disease by the type of localized erythema. In 94,5% of cases, the diagnosis was confirmed by ELISA, in 8,98% by PCR. In 100% of cases, patients received antibacterial therapy. No complications were detected.

Acinetobacter baumannii transformants expressing oxacillinases and metallo-β-lactamases that confer resistance to meropenem: new tools for anti-Acinetobacter drug development and AMR preparedness.

Antimicrobial resistance (AMR) in Acinetobacter baumannii is an unmet medical need. Multiple drug-resistant/extremely drug-resistant strains of A. baumannii do not display growth well in in vivo models, and consequently, their response to antibacterial therapy is inconsistent. We addressed this issue by engineering carbapenem resistance motifs into the highly virulent genetic background of A. baumannii AB5075. This strain has a chromosomally encoded oxa-23 that was deleted (Δoxa-23), then plasmids expressing oxa-23, oxa-24/40, oxa-58, imp-1, vim-2, and ndm-1 were introduced to create the mutant strains. Each transformant was used as a challenge strain in a neutropenic murine thigh infection model and assessed for the extent of growth and response to meropenem 200 mg/kg subcutaneously every 6 h (q6h). Pharmacodynamic analyses were performed by transforming drug exposure from dose (mg/kg) to the fraction of the dosing interval; free meropenem concentrations were >minimum inhibitory concentration (MIC) (fT > MIC). AB5075 and the AB5075Δoxa-23 mutant had a MICs of 32 and 4 mg/L, respectively. The transformants harboring oxacillinases oxa-24/40 and oxa-58 had an MIC of 64 mg/L. The metallo-β-lactamases imp-1, vim-2, and ndm-1 had MICs of 128, 64, and 64 mg/L, respectively. All vehicle-treated transformants displayed in vivo growth in the range of 0.75-1.4 log. The response to meropenem was consistent with the varying fT > MIC of the transformants and was readily described by an inhibitory sigmoid Emax relationship. Stasis was achieved with a fT > MIC of 0.36. These A. baumannii transformants are invaluable new tools for the assessment of anti-Acinetobacter compounds and provide a new pathway for AMR preparedness.

Localized Surface Plasmon Resonance-Enhanced Photocatalytic Antibacterial of In Situ Sprayed 0D/2D Heterojunction Composite Hydrogel for Treating Diabetic Wound.

Chronic diabetic wounds pose significant challenges due to uncontrolled bacterial infections, prolonged inflammation, and impaired angiogenesis. The rapid advancement of photo-responsive antibacterial therapy shows promise in addressing these complex issues, particularly utilizing 2D heterojunction materials, which offer unique properties. Herein, an in situ sprayed Bi/BiOCl 0D/2D heterojunction composite fibrin gel with the characteristics of rapid formation and effective near-infrared activation is designed for the treatment of non-healing diabetes-infected wounds. The sprayed composite gel can provide protective shielding for skin tissues and promote endothelial cell proliferation, vascularization, and angiogenesis. The Bi/BiOCl 0D/2D heterojunction, with its localized surface plasmon resonance (LSPR), can overcome the wide bandgap limitation of BiOCl, enhancing the generation of local heat and reactive oxygen species under near-infrared irradiation. This facilitates bacterial elimination and reduced inflammation, supporting the accelerated healing of diabetes-infected wounds. This study underscores the potential of LSPR-enhanced heterojunctions as advanced wound therapies for chronic diabetic wounds.

Nitrogen Vacancy Modulation of Tungsten Nitride Peroxidase-Mimetic Activity for Bacterial Infection Therapy.

Bacterial infections claim millions of lives every year, with the escalating menace of microbial antibiotic resistance compounding this global crisis. Nanozymes, poised as prospective substitutes for antibiotics, present a significant frontier in antibacterial therapy, yet their precise enzymatic origins remain elusive. With the continuous development of nanozymes, the applications of elemental N-modulated nanozymes have spanned multiple fields, including sensing and detection, infection therapy, cancer treatment, and pollutant degradation. The introduction of nitrogen into nanozymes not only broadens their application range but also holds significant importance for the design of catalysts in biomedical research. The synergistic interplay between W and N induces pivotal alterations in electronic configurations, endowing tungsten nitride (WN) with a peroxidase-like functionality. Furthermore, the introduction of N vacancies augments the nanozyme activity, thus amplifying the catalytic potential of WN nanostructures. Rigorous theoretical modeling and empirical validation corroborate the genesis of the enzyme activity. The meticulously engineered WN nanoflower architecture exhibits an exceptional ability in traversing bacterial surfaces, exerting potent bactericidal effects through direct physical interactions. Additionally, the topological intricacies of these nanostructures facilitate precise targeting of generated radicals on bacterial surfaces, culminating in exceptional bactericidal efficacy against both Gram-negative and Gram-positive bacterial strains along with notable inhibition of bacterial biofilm formation. Importantly, assessments using a skin infection model underscore the proficiency of WN nanoflowers in effectively clearing bacterial infections and fostering wound healing. This pioneering research illuminates the realm of pseudoenzyme activity and bacterial capture-killing strategies, promising a fertile ground for the development of innovative, high-performance artificial peroxidases.

Mimics of Host Defense Peptides Derived from Dendronized Polylysines for Antibacterial and Anticancer Therapy.

Bacteria in tumor microenvironments promote carcinogenesis and trigger complications, suggesting the significance of intervening in bacterial growth in cancer treatment. Here, dendrimer-derived mimics (DMs) of host defense peptides (HDPs) were designed for antibacterial and anticancer therapy, which feature a dendronized polylysine core and polycaprolactone arms. DMs displayed not only remarkable activities against Staphylococcus aureus and human lung cancer cells, but also exceptional selectivity. The membranolytic mechanism revealed by morphology analysis explained their low susceptibility to induce resistance. Further, the optimized DM inhibited tumor growth in the subcutaneous tumor model when administered via intraperitoneal injection and exhibited negligible toxicity to tissues. Overall, we combined the superiority of dendrimers and the mechanism from HDPs to design agents with dual antibacterial and anticancer activities that possess great potential for clinical oncology therapy.

A study on selected responses and immune structures of broiler chickens with experimental colibacillosis with or without florfenicol administration

BackgroundColibacillosis in broiler chickens is associated with economic loss and localized or systemic infection. Usually, the last resort is antibacterial therapy. Insight into the disease pathogenesis, host responses and plausible immunomodulatory effects of the antibacterials is important in choosing antibacterial agent and optimization of the treatment. Selected responses of broiler chickens experimentally infected with Escherichia coli (E. coli) and also those treated with florfenicol are evaluated in this study. Chickens (n = 70, 5 weeks old) were randomly assigned to four groups. The control groups included normal control (NC) and intratracheal infection control (ITC) (received sterile bacterial medium). The experimental groups consisted of intratracheal infection (IT) that received bacterial suspension and intratracheal infection with florfenicol administration (ITF) group.ResultsFlorfenicol reversed the decreased albumin/globulin ratio to the level of control groups (p > 0.05). Serum interleukin 10 (IL-10) and interferon‐gamma (IFN-γ) concentrations decreased in IT birds as compared to NC group. Florfenicol decreased the serum interleukin 6 (IL-6) concentration as compared to IT group. Milder signs of inflammation, septicemia, and left shift were observed in the leukogram of the ITF group. Florfenicol decreased the severity of histopathological lesions in lungs and liver. Depletion of lymphoid tissue was detected in spleen, thymus and bursa of IT group but was absent in ITF birds. The number of colony forming units of E. coli in liver samples of ITF group was only slightly lower than IT birds.ConclusionsExperimental E. coli infection of chickens by intratracheal route is associated with remarkable inflammatory responses as shown by changes in biochemical and hematological parameters. Histopathological lesions in lymphoid organs (especially in the spleen) were also prominent. Florfenicol has positive immunomodulatory effects and improves many of the lesions before the full manifestation of its antibacterial effects. These effects of florfenicol should be considered in pharmacotherapy decision-making process.

Calcium Sulfate Disks for Sustained-Release of Amoxicillin and Moxifloxacin for the Treatment of Osteomyelitis.

The purpose of this in vitro study was to develop calcium sulfate (CS)-based disks infused with an antimicrobial drug, which can be used as a post-surgical treatment modality for osteomyelitis. CS powder was embedded with 10% antibiotic, amoxicillin (AMX) or moxifloxacin (MFX), to form composite disks 11 mm in diameter that were tested for their degradation and antibiotic release profiles. For the disk degradation study portion, the single drug-loaded disks were placed in individual meshes, subsequently submerged in phosphate-buffered saline (PBS), and incubated at 37 °C. The disks were weighed once every seven days and analyzed via Fourier-transform infrared spectroscopy, X-ray diffraction, energy dispersive X-ray spectroscopy, and scanning electron microscopy. During the antibiotic release analysis, composite disks were placed in PBS solution, which was changed every 3 days, and analyzed for antibiotic activity and efficacy. The antibacterial effects of these sustained-release composites were tested by agar diffusion assay using Streptococcus mutans (S. mutans) UA 159 as an indicator strain. The degradation data showed significant increases in the degradation of all disks with the addition of antibiotics. Following PBS incubation, there were significant increases in the amount of phosphate and decreases in the amount of sulfate. The agar diffusion assay demonstrated that the released concentrations of the respective antibiotics from the disks were significantly higher than the minimum inhibitory concentration exhibited against S. mutans over a 2-3-week period. In conclusion, CS-antibiotic composite disks can potentially serve as a resorbable, osteoconductive, and antibacterial therapy in the treatment of bone defects and osteomyelitis.

Respiration suppress and apoptosis-like cell death of Escherichia coli in direct current therapy mediated by polypyrrole conductive hydrogel

Targeting oxidative phosphorylation of bacteria is a novel antibiotic strategy leading to rapid cell death as a result of respiration suppress. Herein, a conductive polymer termed polypyrrole (PPy) is used to short-circuit the electron transfer chain (ETC) of bacteria cells owing to its higher electron affinity to electrons than all of the electron carriers on ETC. A hydrogel is fabricated using PPy which is anticipated to seize electrons from ETC and inhibit respiration of bacteria cells. The results show that the prepared PPy hydrogel can mediate an effective direct current (DC) antibacterial therapy which greatly enhances intracellular reactive oxygen species (ROS) level of Escherichia coli (E. coli), suppresses respiration, induces apoptosis-like cell death of E. coli accompanied by chromosomal condensation and loss of structural integrity, and rapidly cleared E. coli infection in vivo. Taken into the photothermal property of PPy, a combined direct current-photothermal therapy is developed which can enhance bacteria-killing effects with the assistance of an 808 nm laser. Our findings provide a new antibiotic strategy with metabolic pathway as a target.

Caffeic Acid and Cyclen-Based Hydrogel for Synergistic Antibacterial Therapy.

Caffeic acid is a natural product that contains both phenolic and acrylic functional groups and has been widely employed as an alternative drug to combat chronic infections induced by microbes such as bacteria, fungi, and viruses. Several strategies, including derivatization and nanoformulation, have been applied in order to overcome the issues of water insolubility, poor stability, and the bioavailability of caffeic acid. Here, caffeic acid and cyclen-Zn(II) are incorporated into a G4-assembly by using a phenylborate linker to form the mixed supramolecular prodrug GB-CA/Cy-Zn(II) hydrogel. The delivery system is expected to enhance antibacterial and anti-inflammatory properties during the wound healing process through the synergistic effect of caffeic acid and cyclen-Zn(II). The preparation and physicochemical and mechanical properties of the hydrogel were investigated by NMR, CD, TEM, and rheological assays. The typical inflammatory cytokines and in vitro antibacterial experiments indicated that inflammation and infection can be significant suppressed by the hydrogel treatment. An in vivo infected wound model treated by the hydrogel showed rapid wound healing capacity and biosafety. The current work depicts a simple method to prepare a caffeic acid hydrogel carrier, which facilitates synergistic treatment for inflammation and bacterial infections at the wound site.

Optimising antibacterial utilisation in Argentine intensive care units: a quality improvement collaborative

BackgroundThere is limited evidence from antimicrobial stewardship programmes in less-resourced settings. This study aimed to improve the quality of antibacterial prescriptions by mitigating overuse and promoting the use of narrow-spectrum...