Potent Antimicrobial Effects Research Articles

An overview of uses and effectiveness of intracanal medicaments in endodontics

Intracanal medicaments play a crucial role in endodontics by addressing microbial infections and facilitating the healing of periapical tissues. Their effectiveness lies in their ability to disinfect the root canal system, eliminate biofilms, neutralize bacterial endotoxins, and promote tissue repair. Calcium hydroxide, a widely used traditional medicament, demonstrates strong antimicrobial properties and creates an alkaline environment unfavorable for bacterial survival. However, its limitations against certain resistant pathogens and restricted penetration into dentinal tubules have driven the development of advanced alternatives. Emerging medicaments such as nanoparticle-based formulations and bioglass offer promising solutions by overcoming these limitations. Nanoparticles, with their ability to penetrate complex canal systems, deliver potent antimicrobial effects and enhance disinfection efficiency. Bioglass not only disrupts bacterial activity but also facilitates dentinal remineralization, making it particularly valuable in regenerative procedures. Hydrogels, designed for controlled and sustained drug release, improve the delivery of medicaments into anatomical complexities, enhancing their overall efficacy. Natural products like neem, propolis, and aloe vera are gaining attention for their biocompatibility and antimicrobial capabilities, providing effective alternatives for patients’ sensitive to synthetic agents. These formulations also address concerns about resistance and toxicity associated with conventional options. Advances in delivery systems, including sonic and ultrasonic activation, further amplify the efficacy of both traditional and emerging medicaments. Comparative analyses of these approaches highlight the advantages of integrating innovative technologies with proven methods, enabling clinicians to address complex infections and improve long-term treatment outcomes. The evolving landscape of intracanal medicaments continues to push the boundaries of what can be achieved in endodontics, promising enhanced patient care through effective disinfection and tissue healing.

Selective toxicity of a novel antimicrobial peptide Acidocin 4356 against Pseudomonas aeruginosa and Acinetobacter baumannii in human cell-based in vitro infection models

Prior studies examined Acidocin 4356’s antibacterial and antivirulence effects against Pseudomonas aeruginosa, including cell membrane penetration abilities. Building on prior research, an in-vitro co-culture of human cells was established to evaluate the selectivity of Acidocin (ACD) by concurrently cultivating human cells and bacterial pathogens. This study evaluated the antibacterial effectiveness of ACD against Acinetobacter baumannii and Pseudomonas aeruginosa. Laser scanning confocal microscopy (LSCM) and scanning electron microscopy (SEM) revealed significant biofilm dispersion at ACD concentrations as low as 1/2 MIC. The cytotoxicity of ACD was evaluated on two human cell lines, Calu-6 and THP-1, using the MTT assay. The IC50 values were 114 µg/mL and 24 µg/mL after a 12-hour treatment duration. In a co-culture model, the IC50 increased to 118 µg/mL, showing greater resilience of THP-1 cells under these settings, mimicking in-vivo conditions. Fluorescent microscopy and flow cytometry analysis confirmed the MTT results, showing ACD’s potent antimicrobial effects and minimal toxicity to human cells, even after 12 h of treatment. Transmission electron microscopy (TEM) study revealed that normal Calu-6 cells included papillary outgrowths and microvilli, while infected cells displayed secretory vesicles, indicating an active response to P. aeruginosa infection. The present study thus serves as a critical step toward the development of an innovative therapeutic strategy targeting biofilm-associated infections.

Valorisation of Refosco grape pomace: exploring its antioxidant, antimicrobial, and antiadhesive properties

Abstract Agricultural by-products, including winery waste, represent both an environmental challenge and a valuable source of bioactive compounds. This study investigated the antioxidative, antimicrobial, and antiadhesive properties of grape seed and peel extracts derived from the red wine variety Refosco. Water and methanol extracts were prepared from dried, ground seeds and peels, both before and after supercritical extraction (SFE). The total antioxidant capacity (TAC) of water- and lipid-soluble compounds was measured. Minimal inhibitory concentrations (MICs) and antiadhesion effects of water extracts were then determined for Campylobacter jejuni, Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. The antimicrobial effects were further evaluated in pasta dough as a model food matrix. Our results showed that some methanol extracts exhibited significantly higher TAC values compared to water extracts. However, the TAC of water-soluble compounds was significantly higher than that of lipid-soluble compounds, regardless of the solvent used. Although the TAC of dried seed and peel samples (SDRY; PDRY) was higher than that of SFE residues, the difference was not statistically significant. The most potent antimicrobial effect was observed for SDRY extracts, with MICs as low as 0.625 mg/mL. Additionally, both SDRY and PDRY water extracts, at 1/8 of the MIC, exhibited antiadhesion activity. In conclusion, red grape pomace from the Refosco variety proves to be a cost-effective source of valuable water-soluble compounds with antioxidative, antimicrobial, and antiadhesive properties. Importantly, results showed that the SFE residue retained some bioactive properties, further highlighting the potential of this by-product.

Combining functionalities-nanoarchitectonics for combatting bacterial infection.

New antimicrobial and anti-inflammatory therapeutics are needed because of antibiotic resistance development and resulting complications such as inflammation, ultimately leading to septic shock. The antimicrobial effects of various nanoparticles (NPs) are currently attracting intensive research interest. Although various NPs display potent antimicrobial effects against strains resistant to conventional antibiotics, the therapeutic use of such materials is restricted by poor selectivity between bacteria and human cells, leading to adverse side effects. As a result, increasing research efforts during the last few years have focused on targeting NPs against bacteria and other components in the infection micro-environment. Examples of approaches explored include peptide-, protein- and nucleic acid-based NP coatings for bacterial membrane recognition, as well as NP conjugation with enzyme substrates or other moieties that respond to bacterial or other enzymes present in the infection micro-environment. In general, this study aims to add to the literature on the antimicrobial effects of nanomaterials by discussing surface modification strategies for targeting bacterial membranes and membrane components, as well as how such surface modifications can improve the antimicrobial effects of nanomaterials and simultaneously decrease toxicity towards human cells and tissues. In doing so, the biological effects observed are related throughout to the physico-chemical modes of action underlying such effects.

Current Advances in Synthesis and Therapeutic Applications of Pyrimidine

Pyrimidine derivatives are fundamental heterocyclic compounds that serve as essential components of nucleic acids, including uracil, thymine, and cytosine. Modern synthetic approaches for functionalized pyrimidines encompass metal-catalyzed reactions, multicomponent coupling strategies, and green chemistry protocols. The biological significance of pyrimidine scaffolds has led to numerous therapeutic applications across multiple disease states. Pyrimidine-based drugs demonstrate potent antimicrobial effects through antifolate mechanisms, as seen with trimethoprim and pyrimethamine. In antiviral therapy, modifications of the pyrimidine core have yielded effective agents like zidovudine for HIV treatment. Anticancer applications include 5-fluorouracil and related compounds that interfere with nucleic acid synthesis. Pyrimidine derivatives also show promise in treating metabolic disorders, with applications in hyperthyroidism and hyperlipidemia management. Structure-activity relationships reveal that subtle modifications of the pyrimidine scaffold can significantly alter therapeutic properties. The integration of pyrimidine moieties into drug design continues to generate novel therapeutic agents with enhanced efficacy and reduced side effects

Visible-Light-Activated TiO2-Based Photocatalysts for the Inactivation of Pathogenic Bacteria

Pathogenic bacteria in the environment pose a significant threat to public health. Titanium dioxide (TiO2)-based photocatalysts have emerged as a promising solution due to their potent antimicrobial effects under visible light and their generally eco-friendly properties. This review focuses on the antibacterial properties of visible-light-activated, TiO2-based photocatalysts against pathogenic bacteria and explores the factors influencing their efficacy. Various TiO2 modification strategies are discussed, including doping with non-metals, creating structure defects, combining narrow-banded semiconductors, etc., to extend the light absorption spectrum from the UV to the visible light region. The factors affecting bacterial inactivation, and the underlying mechanisms are elucidated. Although certain modified TiO2 nanoparticles (NPs) show antibacterial activities in the dark, they exhibit much higher antibacterial efficacies under visible light, especially with higher light intensity. Doping TiO2 with elements such as N, S, Ce, Bi, etc., or introducing surface defects in TiO2 NPs without doping, can effectively inactivate various pathogenic bacteria, including multidrug-resistant bacteria, under visible light. These surface modifications are advantageous in their simplicity and cost-effectiveness in synthesis. Additionally, TiO2 can be coupled with narrow-banded semiconductors, resulting in narrower band gaps and enhanced photocatalytic efficiency and antibacterial activities under visible light. This information aids in understanding the current technologies for developing visible-light-driven, TiO2-based photocatalysts and their application in inactivating pathogenic bacteria in the environment.

Marine Peptides: Potential Basic Structures for the Development of Hybrid Compounds as Multitarget Therapeutics for the Treatment of Multifactorial Diseases.

Marine-derived peptides display potent antihypertensive, antioxidant, analgesic and antimicrobial biological effects. Some of them have also been found to have anticancer activity via various mechanisms differing from those of continental organisms. This diversity of properties-together with the peptides' efficacy, which has been confirmed in several in vitro and in vivo studies-make these compounds attractive as functional ingredients in pharmacy, especially in regard to multitarget drugs known as hybrids. Given the possibilities offered by chimeric structures, it is expected that a hybridization strategy based on a marine-derived compound could result in a long-awaited success in the development of new effective compounds to combat a range of complex diseases. However, despite the fact that the biological activity of such new hybrids may exceed that of their parent compounds, there is still an urgent need to carefully determine their potential off-targets and thus possible clinically important side effects. Given the above, the aim of this paper is to provide information on compounds of marine origin with peptide structures and to verify the occurrence and usage of hybrid compounds built from these structures. Furthermore, the authors believe that information presented here will serve to increase public awareness of the new opportunities arising from the combination of hybridization strategies with marine molecules with known structures and biological properties, thereby accelerating the development of effective drug candidates.

Exploring the Efficacy of pH-Responsive Vancomycin/Ag/ZIF-8 Nanoparticles Modified with Hyaluronic Acid for Enhanced Antibacterial Therapy and Wound Healing.

This study introduces a novel type of metal-organic framework material, specifically zeolitic imidazolate framework-8 (ZIF-8), that is integrated with silver nanoparticles and further enhanced by incorporating vancomycin (Van) to create a composite named as Van/Ag/ZIF-8. This composite demonstrates a potent and smart antimicrobial effect due to its ability for releasing silver ions and Van in a controlled manner, especially in the microacidic conditions surrounding bacterial cells. Furthermore, we used hyaluronic acid to modify Van/Ag/ZIF-8, resulting in a composite denoted as Van/Ag/ZIF-8@HA. This composite exhibits a significant inhibition effect against the proliferation of both Gram-negative (Escherichia coli 100%) and Gram-positive (Staphylococcus aureus 99.9%) resistant bacterial strains while exerting no adverse effects on animal cellular growth. These findings underscore its favorable biocompatibility profile. The experimental results show a combined antibacterial action against prevalent bacterial infections, which is supported by in vivo experiments using a skin wound model. This work confirms the composite's significant role in fighting pathogenic infections and aiding in healing skin wounds. The innovative strategy not only tackles the pressing issue of antibiotic-resistant bacterial infections but also marks a significant advancement in the areas of wound healing and medical research, offering a promising path for future investigations and therapeutic uses.

Seasonal Variation in the Chemical Composition and Antimicrobial Activity of Essential oil Obtained from Moroccan Lavender Lavandula maroccana Murb. Collected from the Wild

Background: Lavandula maroccana Murb. is renowned for its valuable essential oil (EO), with a complex chemical composition and potent antimicrobial properties, which can be subjected to environmental influences. The objective of the present study was to assess how seasonal variations affect the yield, chemical composition and antimicrobial activity of Lavandula maroccana Murb. EO. Methods: The plant materials were collected throughout the four seasons and subjected to EO extraction using hydro-distillation method. The chemical composition was analyzed using gas chromatography/mass spectrometry (GC/MS), while the antimicrobial properties were evaluated using disc diffusion and microdilution assays against four yeasts ( Candida albicans, C. glabrata, C. krusei, and C. parapsilosis), and six pathogenic bacteria ( Staphylococcus aureus, Micrococcus luteus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae). Results: The highest EO yield was recorded from the samples collected in autumn (0.19%), while the spring harvest yielded the lowest EO production (0.06%). The GC/MS analysis identified 41 different compounds, with notable variations in the major compound, carvacrol, which ranged from 29.33% to 60.60%. The summer collections contained the highest concentration of carvacrol. Antimicrobial testing, revealed that EOs obtained from all seasons displayed substantial activity against both bacteria and yeast strains. Notably, the summer-harvested EO showed the most potent antimicrobial effects, with inhibition zone and MIC values ranging from 15.32 ± 0.45 mm to 24.09 ± 0.65 mm and 0.16 mg/mL to 2.50 mg/mL, respectively. Conversely, the spring-harvested EO showed the least antimicrobial activity. Conclusion: These findings emphasize the importance of harvesting L. maroccana during the summer and/or autumn to maximize the EO yield and carvacrol content, thereby enhancing its antimicrobial effectiveness.

Relationships of Prodiginins Mechanisms and Molecular Structures to their Antiproliferative Effects.

The Prodiginins (PGs) natural pigments are secondary metabolites produced by a broad spectrum of gram-negative and gram-positive bacteria, notably by species within the Serratia and Streptomyces genera. These compounds exhibit diverse and potent biological activities, including anticancer, immunosuppressive, antimicrobial, antimalarial, and antiviral effects. Structurally, PGs share a common tripyrrolic core but possess variable side chains and undergo cyclization, resulting in structural diversity. Studies have investigated their antiproliferative effects on various cancer cell lines, with some PGs advancing to clinical trials for cancer treatment. This review aims to illuminate the molecular mechanisms underlying PG-induced apoptosis in cancer cells and explore the structure-activity relationships pertinent to their anticancer properties. Such insights may serve as a foundation for further research in anticancer drug development, potentially leading to the creation of novel, targeted therapies based on PGs or their derivatives.

Unraveling the therapeutic potential of Satureja nabateorum extract: inducing apoptosis and cell cycle arrest through p53, Bax/Bcl-2, and caspase-3 pathways in human malignant cell lines, with in silico insights

Satureja nabateorum, known as Nabatean savory is a Lamiaceae plant native to the Arabian Peninsula, specifically in the mountainous regions of Saudi Arabia. The study aims to investigate the phytochemical components of the S. nabateorum leaves (SNL) and stems (SNS) extract and to assess their antioxidant, antimicrobial, and antiproliferative properties. Methanol extracts from leaves and stems were analyzed for chemical constituents using the GC-MS technique. Antioxidant capacities were measured using hydrogen peroxide and ABTS radical-scavenging methods, and antimicrobial activity was tested against various microorganisms. Cytotoxic activity on four human malignant cell lines was assessed using MTT and flow cytometry. Molecular docking and molecular dynamics studies were conducted to understand the interactions and binding modes of the extracted compounds at a molecular level. GC-MS analysis of SNL extract revealed thymol, carvacrol, and p-cymen-8-ol as major constituents. SNS extract contained β-sitosterol, stigmasterol, lupeol, and lup-20(29)-ene-3β,28-diol. SNS extract exhibited more potent antioxidant, antimicrobial, and anticancer effects than SNL extract. The extract, SNS, exhibited potential toxicity in A549 cells with an IC50 value of 3.62 µg/mL and induced marked apoptotic effects with S phase-cell cycle arrest. SNS extract also showed higher levels of Caspase 3, Bax, p53, and the Bax/Bcl2 ratio and lower levels of Bcl-2. Molecular docking and dynamic simulation supported these findings, targeting the EGFR TK domain. The study suggests that the S. nabateorum stem extract holds promise as a potent antimicrobial, antioxidant, and anticancer agent. It provides valuable insights for considering the extract as a substitute for chemotherapy and/or protective agents.

Bioinspired Glycopeptide Hydrogel Reestablishing Bone Homeostasis through Mediating Osteoclasts and Osteogenesis in Periodontitis Treatment.

Irreversible alveolar bone resorption is one of the important clinical manifestations of periodontitis, which is initiated by a plaque biofilm and exacerbated by the imbalance of osteoclast activity and osteogenesis, affecting a patient's masticatory function and resulting in a high recurrence rate of periodontitis. Herein, to reestablish bone homeostasis in periodontitis, a minocycline hydrochloride (MH)-loaded glycopeptide hydrogel (MH/GRWgel) is fabricated to mediate alveolar bone absorption through sequential antibacterial and RANKL-blocking activities. GRWgel shows an ECM-like fibrous and porous microstructure serving as a scaffold for cell proliferation and differentiation and holds the merits including injectability, self-healing properties, and good biocompatibility. After injection in situ, MH is released rapidly from the hydrogel in the early stage, demonstrating a potent antimicrobial effect to combat the biofilm in the deep periodontal pocket. Moreover, MH/GRWgel exhibits a high specific binding efficiency with RANKL to suppress osteoclast maturation by shielding the RANKL/RANK interaction and enhancing osteogenic differentiation, thereby synergistically regulating bone homeostasis. In the rat periodontitis model, MH/GRWgel significantly curtails periodontitis progression through antimicrobial activity, inhibition of alveolar bone resorption, and promotion of bone regeneration, which is superior to the treatment of a commercial gel. These findings suggest that MH/GRWgel with superiority in regulating bone homeostasis provides a promising therapeutic strategy for periodontitis.

The investigation prospect application of alcohol-water extract of lingonberry as antimicrobial, anti-fungi and antioxidant pharmaceutical

Infection diseases is a worldwide important problem for medicine and pharmacy. Every year 13.7 million people die from bacterial infections in the world. Thus, the search of new compounds with antimicrobial and anti-fungi activity is topical for today. The object of the study was lingonberry leaf 60% extract. The content of phenylpropanoids derivatives was evaluated by spectrophotometric method of analysis, whereas organic acids by alkalimetric method; antioxidant power was found by potentiometric method; antibacterial and antifungal activity was assessed by the method of “wells”. According to the results of the study, it was shown that the lingonberry leaf extract is inferior to the green tea leaf extract in terms of the content of phenolic compounds, catechins, hydroxycinnamic and organic acids, but flavonoids dominate in the lingonberry extract. The study found that lingonberry leaf extract has a high level of antioxidant activity. When comparing the levels of antioxidant action of lingonberry extract with green tea extract and the «gold standard» – аepigallocatechin-3-O-gallate in one concentration of 0.03 mol/L, it was found that lingonberry extract had the best result. Escherichia coli bacteria was the most sensitive to the extract whereas Pseudomonas aeruginosa was the most resistant. This work shows that 60% ethanolic lingonberry leaf extract has potent antioxidant, antimicrobial and antifungal effects. According to the obtained results, it can be concluded that 60% V. vitis-idaea leaf extract is promising for the development of new antimicrobial, antifungal and antioxidant pharmaceutical.

Marsupial immune protection is shaped by enhancer sharing and gene cluster duplication of cathelicidin antimicrobial peptides.

Marsupial neonates are born with immature immune systems, making them vulnerable to pathogens. While neonates receive maternal protection, they can also independently combat pathogens, though the mechanisms remain unknown. Using the sugar glider (Petaurus breviceps) as a model, we investigated immunological defense strategies of marsupial neonates. Cathelicidins, a family of antimicrobial peptides expanded in the genomes of marsupials, are highly expressed in developing neutrophils. Sugar glider cathelicidins reside in two genomic clusters and their coordinated expression is achieved by enhancer sharing within clusters and long-range physical interactions between clusters. These cathelicidins modulate immune responses and have potent antimicrobial effects, sufficient to provide protection in a mouse model of sepsis. Lastly, cathelicidins have a complex evolutionary history, where marsupials and monotremes are the only tetrapods that retained two cathelicidin clusters. Thus, cathelicidins are critical mediators of marsupial immunity, and their evolution reflects the life history-specific immunological needs of these animals.

Ceylon cinnamon (<em>Cinnamomum zeylanicum</em>): Unveiling the health potential

Cinnamomum zeylanicum provides numerous health benefits linked to its phytochemical composition, which varies by maturity, storage conditions, and genotypes. As previous studies have not examined how these factors affect the antioxidant, antimicrobial, and anticancer properties of C. zeylanicum, this study aims to address this gap and explore its broader applications. Both leaves and bark of seed-propagated (N) and vegetatively propagated varieties, Sri Gemunu (G) and Sri Vijaya (V) were used in the study. Three maturity stages, i.e.: 1-3 years (M3), 3-5 years (M2), and >5 years (M1) were subjected to the analysis in each case. Antioxidant activity was assessed using DPPH and FRAP assays, considering storage conditions (room temperature, 4°C) and storage duration of 1 week to 12 months. The most promising samples were then evaluated for antimicrobial and anticancer activity against MCF-7 and Hep-G2 cells. The results showed that NM1 leaves displayed heightened RSA [IC50: 0.27 ± 0.04 mgmL-1] whereas NM1 bark gave varied radical scavenging activity (RSA) values exhibiting the highest RSA (0.60 ± 0.09 mgmL-1). Maturity-influenced antioxidant activity of GM1 leaves exhibited the highest FRAP values at 2358.8 μmol FeSO4/g dry weight (DW). Bark of GM1 recorded FRAP value of 2770.0 ± 3.19 μmol FeSO4/g DW. Enhanced methanolic extracts (MeOH-Ex) from NM1 leaves and the bark demonstrated potent antimicrobial effects, inhibiting Staphylococcus aureus (MIC: 2.5 mgmL-1) and displaying robust anti-fungal activity against Candida albicans (MIC: 0.078 μgmL-1). In addition, MeOH-Ex of leaves showed the most potent cytotoxicity against cancer cells, Hep-G2 (cell viability: 11.53 ± 0.63%) after 48 hours. The research underscores the remarkable antioxidant, antimicrobial, and anticancer properties in C. zeylanicum leaves and bark, in NM1. This highlights the health benefits of seed-propagated C. zeylanicum over G and V varieties, offering valuable insights for future research and product development.

Construction of a one-stop N-doped negatively charged carbon dot nanoplatform with antibacterial and anti-inflammatory dual activities for wound infection based on biocompatibility

The development of bacterial resistance significantly contributes to the persistence of infections. Although previous studies have highlighted the benefits of metal-doped positive carbon nanodots in managing bacterial wound infections, their mechanism of action is relatively simple and they may pose potential hazards to human cells. Therefore, it is essential to develop a one-stop carbon dot nanoplatform that offers high biocompatibility, antibacterial properties, and anti-inflammatory activities for wound infection management. This study explores the antibacterial efficacy, without detectable resistance, and wound-healing potential of nitrogen-doped (N-doped) negatively charged carbon dots (TPP-CDs). These carbon dots are synthesized using tannic acid (TA), polyethylene polyamine, and polyethylene glycol (PEG) as precursors, with a focus on their biocompatibility. Numerous systematic studies have shown that TPP-CDs can effectively destroy bacterial biofilms and deoxyribonucleic acid (DNA), while also inducing oxidative stress, leading to a potent antimicrobial effect. TPP-CDs also demonstrate the ability to scavenge excess free radicals, promote cellular proliferation, and inhibit inflammatory factors, all of which contribute to improved wound healing. TPP-CDs also demonstrate favorable cell imaging capabilities. These findings suggest that N-doped negatively charged TPP-CDs hold significant potential for treating bacterial infections and offer practical insights for their application in the medical field.

A Narrative Review of Bedaquiline and Delamanid: New Arsenals Against Multidrug-Resistant and Extensively Drug-Resistant Mycobacterium tuberculosis.

The treatment of multidrug-resistant (MDR-) and extensively drug-resistant tuberculosis (XDR-TB) is a formidable challenge. Treatment of MDR- and XDR-TB using bedaquiline (BDQ) and delamanid (DLM), two newly introduced medications, is steadily increasing. This narrative review aimed to present a concise overview of the existing information regarding BDQ and DLM, and elucidate their antimicrobial characteristics, resistance mechanisms, synergism with other drugs, and side effects. To collect the required information about the antimicrobial properties, a search for scientific evidence from the Scopus, PubMed, and Embase databases was performed, and all recently published articles up to May 2024 were considered. BDQ had potent antimicrobial effects on various types of nontuberculous mycobacteria (NTM), including rapid-growing and slow-growing species, and MDR/XDR Mycobacterium tuberculosis. The mechanisms of BDQ resistance in M. tuberculosis primarily involve mutations in three genes: atpE, mmpR (Rv0678) and pepQ. BDQ may have synergistic effects when combined with DLM, pyrazinamide, and pretomanid/linezolid. BDQ has a low incidence of side effects. The use of BDQ may prolong the QTc interval. Similarly, DLM showed potent antimicrobial effects on NTM and MDR/XDR M. tuberculosis. The main resistance mechanisms to DLM are induced by mutations in fbiA, fbiB, fbiC, fgd1, and ddn genes. The DLM had synergistic effects with BDQ and moxifloxacin. The DLM also has few side effects in some patients including QTc prolongation. BDQ and DLM are suitable antibiotics with few side effects for the treatment of MDR/XDR-TB. These antibiotics have synergistic effects when combined with other antituberculosis drugs.

Near-Infrared Light-Mediated Antibacterial Photodynamic Therapy Based on Erythrosine-Functionalized Mesoporous Silica-Coated Upconversion Nanoplatform.

Infectious diseases caused by bacteria pose a serious threat to public health, and more worryingly, the unregulated application of antibiotics accelerates the emergence of bacterial resistance, presenting a major challenge to the effective treatment of infectious diseases caused by bacteria. Therefore, there is an urgent necessity to develop efficient and safe antimicrobial systems. Photodynamic therapy (PDT) is an attractive therapeutic approach that does not induce bacterial resistance. However, the clinical application of PDT has been limited by several factors, including the lower tissue penetration depth of photoactivation under visible light irradiation and the uncertain biosafety of photosensitizers (PS). This work presents an near infrared (NIR)-triggered core-shell upconversion nanoparticle-based PDT system composed of mesoporous silica-coated lanthanide-doped upconversion nanoparticles loaded with the photosensitizer erythrosine (UCSE). Upon NIR-triggering, erythrosine generates highly efficient reactive oxygen species that disrupt the cell membranes of Staphylococcus aureus and Escherichia coli, exhibiting a potent photodynamic antimicrobial effect. It is worth noting that the UCSE also exhibits excellent biosafety. In conclusion, we present an efficient NIR-triggered nanoantimicrobial system with excellent antimicrobial capacity and biosafety, which is a new therapeutic strategy for the control of bacterial infectious diseases.

Harnessing Plant-Based Nanoparticles for Combatting Multidrug-Resistant Bacteria

The emergence of multidrug-resistant organisms poses a significant challenge to public health worldwide. In response, plant-based nanoparticles have garnered attention for their potential as novel antimicrobial agents. These nanoparticles are derived from various plant sources and exhibit inherent antimicrobial properties due to their phytochemical composition. Nanoparticles synthesized from spinach (Spinacia oleracea) and orange (Citrus sinensis) extracts, loaded with salts of Cu and Zn, were evaluated for their antimicrobial activity against multidrug-resistant bacteria. Antimicrobial efficacy was assessed through agar well diffusion assays against clinically relevant multidrug-resistant bacterial strains of Pseudomonas aeruginosa MTCC 74, Staphylococcus aureus MTCC 902, Klebsiella pneumoniae MTCC 661. The nanoparticles exhibited potent antimicrobial effects, significantly inhibiting the growth of tested bacteria even when compared to commercially available antibiotics. These findings highlight the potential of plant-based nanoparticles loaded with Cu and Zn salts as effective agents against multidrug-resistant bacteria, offering a promising avenue for future antimicrobial therapies.

Recent advances in the therapeutic potential of cathelicidins.

The alarming increase in antimicrobial resistance in the last decades has prompted the search for alternatives to control infectious diseases. Antimicrobial peptides (AMPs) represent a heterogeneous class of molecules with ample antibacterial, antiviral, and antifungal effects. They can be found in many organisms, including all classes of vertebrates, providing a valuable source of new antimicrobial agents. The unique properties of AMPs make it harder for microbes develop resistance, while their immunomodulatory properties and target diversity reinforce their translational use in multiple diseases, from autoimmune disorders to different types of cancer. The latest years have witnessed a vast number of studies evaluating the use of AMPs in therapy, with many progressing to clinical trials. The present review explores the recent developments in the medicinal properties of cathelicidins, a vast family of AMPs with potent antimicrobial and immunomodulatory effects. Cathelicidins from several organisms have been tested in disease models of viral and bacterial infections, inflammatory diseases, and tumors, with encouraging results. Combining nanomaterials with active, natural antimicrobial peptides, including LL-37 and synthetic analogs like ceragenins, leads to the creation of innovative nanoagents with significant clinical promise. However, there are still important limitations, such as the toxicity of many cathelicidins to healthy host cells and low stability in vivo. The recent advances in nanomaterials and synthetic biology may help overcome the current limitations, enabling the use of cathelicidins in future therapeutics. Furthermore, a better understanding of the mechanisms of cathelicidin action in vivo and their synergy with other host molecules will contribute to the development of safer, highly effective therapies.