Development Of Antimicrobial Drugs Research Articles

New 24-Membered Macrolactines from an Arctic Bacterium Bacillus amyloliquefaciens SCSIO 41392 and Their Anti-Pathogenicity Evaluation

Three new 24-membered macrolactines, amylomacrolactines A–C (1–3), along with two known compounds 4 and 5, were isolated from the Arctic bacteria Bacillus amyloliquefaciens SCSIO 41392. The configurations of 1–3 were assigned by a combination of coupling constants, NOESY, and analysis of MM2-optimized conformation, as well as by comparison with reports in the literature. Compounds 1 and 2 showed quorum sensing (QS) inhibitory activities against the Pseudomonas aeruginosa (P. aeruginosa) PQS system and suppressed PQS-regulated virulence factor pyocyanin synthesis. In addition, compounds 3–5 affected the production of another essential virulence factor, siderophore of pyoverdine (PVD), in P. aeruginosa. More importantly, compound 5 showed an anti-biofilm activity against P. aeruginosa. Altogether, the isolated compounds displayed multiple bacterial virulence inhibition activities, which is worthy of further exploration for novel analogues in antimicrobial drug development.

PredPVP: A Stacking Model for Predicting Phage Virion Proteins Based on Feature Selection Methods

Background: Phage therapy has a broad application prospect as a novel therapeutic method, and Phage Virion Proteins (PVP) can recognize the host and bind to surface receptors, which is of great significance for the development of antimicrobial drugs for the treatment of infectious diseases caused by bacteria. In recent years, several PVP predictors based on machine learning have been developed, which usually use a single feature to train the learner. In contrast, higher dimensional feature representations tend to contain more potential sequence information. Methods: In this work, we construct a stacking model PredPVP for PVP prediction by combining multiple features and using feature selection methods. Specifically, the sequence is first encoded using seven features. For this high-dimensional feature representation, three feature selection methods wereutilized to remove redundant features, then integrated with eight machine learning algorithms. Finally, probability features and class features (PCFs) generated by 24 base models were put into logistic regression (LR) to train the model. Results: The results of the independent test set indicate that PredPVP has higher performance compared to other existing predictors, with an AUC of 93.4%. Conclusion: We expect PredPVP to be used as a tool for large-scale PVP recognition, providing a new way for the development of novel antimicrobials and accelerating its application in actual treatment. The datasets and source codes used in this study are available at https://github.com/caoqian23/PredPVP.

Structural studies and functional validation of Eugenol and Ferulic acid against Enterococcus faecalis Sortase A.

Enterococcus faecalis (E. faecalis) is commonly occurring pathogen associated with nosocomial infections. Infections are difficult to treat because of their multidrug-resistant (MDR) nature and their tendency to form biofilms. Therefore, it is essential to find alternative medicinal approaches of treatment. In this regard, targeting an important protein for drug development can be an alternative approach. Sortase A (SrtA) is an important enzyme involved in anchoring cell surface-exposed proteins to the cell envelope. SrtA is present in Gram-positive bacteria which catalyses the attachment of several virulence factors and other proteins to the cell membrane. It is involved in bacterial pathogenesis, therefore, it's a promising drug target for the development of anti-microbial drugs targeting cell adhesion, evasion, and biofilm development.To identify SrtA potential inhibitors, we havepurified E. faecalis Sortase A (EfSrtAΔN59). Structural studiesalong with molecular docking of protein with selected ligand molecules were done andconfirmed by MD simulation experiments. We have also performed functional validation of these compounds on bacterial growth, anti-biofilm assays and inhibition assay of selected ligands were also done against E. faecalis individually and in synergistic combinations. Results indicated that both Eugenol and Ferulic acid bind to EfSrtAΔN59 with significant interactions and show promising results.

Current Updates of CRISPR/Cas System and Anti-CRISPR Proteins: Innovative Applications to Improve the Genome Editing Strategies.

The Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR-associated sequence (CRISPR/Cas) system is a cutting-edge genome-editing tool employed to explore the functions of normal and disease-related genes. The CRISPR/Cas system has a remarkable diversity in the composition and architecture of genomic loci and Cas protein sequences. Owing to its excellent efficiency and specificity, this system adds an outstanding dimension to biomedical research on genetic manipulation of eukaryotic cells. However, safe, efficient, and specific delivery of this system to target cells and tissues and their off-target effects are considered critical bottlenecks for the therapeutic applications. Recently discovered anti-CRISPR proteins (Acr) play a significant role in limiting the effects of this system. Acrs are relatively small proteins that are highly specific to CRISPR variants and exhibit remarkable structural diversity. The in silico approaches, crystallography, and cryo-electron microscopy play significant roles in elucidating the mechanisms of action of Acrs. Acrs block the CRISPR/Cas system mainly by employing four mechanisms: CRISPR/Cas complex assembly interruption, target-binding interference, target cleavage prevention, and degradation of cyclic oligonucleotide signaling molecules. Engineered CRISPR/Cas systems are frequently used in gene therapy, diagnostics, and functional genomics. Understanding the molecular mechanisms underlying Acr action may help in the safe and effective use of CRISPR/Cas tools for genetic modification, particularly in the context of medicine. Thus, attempts to regulate prokaryotic CRISPR/Cas surveillance complexes will advance the development of antimicrobial drugs and treatment of human diseases. In this review, recent updates on CRISPR/Cas systems, especially CRISPR/Cas9 and Acrs, and their novel mechanistic insights are elaborated. In addition, the role of Acrs in the novel applications of CRISPP/Cas biotechnology for precise genome editing and other applications is discussed.

Vaginal Tritrichomonas foetus infection in mice as an in vivo model for drug development against Trichomonas vaginalis.

Trichomonas vaginalis is the causative agent of the common sexually transmitted disease, trichomoniasis, which affects more than a hundred million people worldwide. Metronidazole and tinidazole, agents belonging to the 5-nitroheterocyclic class of antimicrobials, are most often used to treat infection, but increased resistance has been reported and adverse effects of these drugs can be significant. Consequently, an urgent need exists for the development of novel drug entities against trichomoniasis. Critical for antimicrobial drug development is the demonstration of in vivo efficacy. Murine models of vaginal T. vaginalis infection are unreliable for unknown reasons. Meanwhile, murine infections with the related bovine pathogen, Tritrichomonas foetus, tend to be more robust, although susceptibility to different antimicrobials might differ from T. vaginalis. Here, we explored the utility of T. foetus infection as a surrogate model for drug development against T. vaginalis. Four different T. foetus strains caused robust vaginal infection in young mice, while none of four diverse T. vaginalis strains did. Comparison of drug susceptibility profiles revealed that T. foetus and T. vaginalis were similarly susceptible to a range of 5-nitroheterocyclic and gold(I) compounds. By comparison, proteasome inhibitors were 10- to 15-fold less active against T. foetus than T. vaginalis, although one of the proteasome inhibitors, bortezomib, had low micromolar activity or better against multiple strains of both trichomonads. Different strains of T. foetus were used to demonstrate the utility of the murine vaginal infection models for in vivo efficacy testing, including for bortezomib and a gold(I) compound. The differences in susceptibility to proteasome inhibitors may be partially explained by differences in the proteasome subunit sequences between the two trichomonads, although the functional relevance of the proteasome was similar in both organisms. These findings indicate that T. foetus can serve as a reliable surrogate model for T. vaginalis in vitro and in murine infections in vivo, but caution must be exercised for specific drug classes with targets, such as the proteasome, that may display genetic divergence between the trichomonads.

Progress in the Study of Natural Antimicrobial Active Substances in Pseudomonas aeruginosa.

The prevalence of antimicrobial resistance reduces the effectiveness of antimicrobial drugs in the prevention and treatment of infectious diseases caused by pathogens such as bacteria, fungi, and viruses. Microbial secondary metabolites have been recognized as important sources for new drug discovery and development, yielding a wide range of structurally novel and functionally diverse antimicrobial drugs for the treatment of a variety of diseases that are considered good producers of novel antimicrobial drugs. Bacteria produce a wide variety of antimicrobial compounds, and thus, antibiotics derived from natural products still dominate over purely synthetic antibiotics among the antimicrobial drugs developed and introduced over the last four decades. Among them, Pseudomonas aeruginosa secondary metabolites constitute a richly diverse source of antimicrobial substances with good antimicrobial activity. Therefore, they are regarded as an outstanding resource for finding novel bioactive compounds. The exploration of antimicrobial compounds among Pseudomonas aeruginosa metabolites plays an important role in drug development and biomedical research. Reports on the secondary metabolites of Pseudomonas aeruginosa, many of which are of pharmacological importance, hold great promise for the development of effective antimicrobial drugs against microbial infections by drug-resistant pathogens. In this review, we attempt to summarize published articles from the last twenty-five years (2000-2024) on antimicrobial secondary metabolites from Pseudomonas aeruginosa.

Molecular descriptors and in silico studies of 4-((5-(decylthio)-4-methyl-4n-1,2,4-triazol-3-yl)methyl)morpholine as a potential drug for the treatment of fungal pathologies

The article explores the polypharmacological profiling of 4-((5-(decylthio)-4-methyl-4H-1,2,4-triazole-3-yl)methyl)morpholine as a potential antimicrobial agent. The study utilized 15148 electronic pharmacophore models of organisms, ranked by the Tversky index. Detailed analysis revealed classical bonding patterns with selected enzymes, identifying key amino acid residues involved in complex formation. Protein target prediction was conducted through various stages using the Galaxy web service, including ligand structure creation, pharmacophore alignment, and target ranking. The activities of the molecules against 1G6C, 2W6O, 3G7F, 3OWU, 4IVR, and 4TZT proteins were compared. Docking studies with PyMOL and Discovery Studio Visualizer revealed binding to thymidine kinase, thiamine phosphate synthase, and biotin carboxylase with promising binding affinities. These interactions suggest potential antibacterial and antiviral effects, warranting further virtual screening and in-depth studies for the development of effective antimicrobial drugs. Calculations of the molecules were made with the gaussian package program. Calculations were made on the 6-31++g** basis set at B3LYP, HF, and M062X levels with Gaussian software. Afterwards, the 0–100 ns interaction of the molecule with the highest activity was examined.

Promising New Targets for the Treatment of Infections Caused by Acinetobacter baumannii: A Review.

Acinetobacter baumannii is a globally disseminated Gram-negative bacterium that causes several types of serious nosocomial infections, the most worrisome being ventilator-associated pneumonia and bacteremia related to using venous catheters. Due to its great ability to form biofilms, combined with its survival for prolonged periods on abiotic surfaces and its potential to acquire and control the genes that determine antibiotic resistance, A. baumannii is at the top of the World Health Organization's priority list of pathogens in urgent need of new therapies. In this sense, this review aimed to present and discuss new molecular targets present in A. baumannii with potential for promising treatment approaches. This review highlights crucial molecular targets, including cell division proteins, membrane synthesis enzymes, and biofilm-associated components, offering promising targets for novel antimicrobial drug development against A. baumannii infections.

ANTIMICROBIAL ACTIVITY OF ETHANOL EXTRACT OF STRYCHNOS SPINOSA LEAVES

The present study determined the antimicrobial activity of the leaf extract of strychnosspinosa. Four extracts were extracted from the leaf of the plant: ethanol, ethylacetate, acetone and chloroform. Phytochemical screening and agar well diffusion methods were employed,Phenols was the phytochemical determined due to its vasatile biological activities. Pseudomonas aeriuginosa, Escherichia coli, Salmonella typhi and Staphylococcus aureus were the test microorganisms used. Ampicilline and tetracycline were the controls. Ethanolic extract indicated promising antimicrobial activity at 10 mg/cm3 and 100 mg/cm3 against the tested microorganisms near the controls. These may likely be as a result of the high concentration of phenols in the ethanolic extract. Strychnosspinosa leaf ethanol extract could be a good option for antimicrobial drug development.

Nanoemulsions of essential oils against multi-resistant microorganisms: An integrative review

Microbial resistance to drugs continues to be a global public health issue that demands substantial investment in research and development of new antimicrobial agents. Essential oils (EO) have demonstrated satisfactory and safe antimicrobial action, being used in pharmaceutical, cosmetic, and food formulations. In order to improve solubility, availability, and biological action, EO have been converted into nanoemulsions (NE). This review identified scientific evidence corroborating the antimicrobial action of nanoemulsions of essential oils (NEEO) against antibiotic-resistant pathogens. Using integrative review methodology, eleven scientific articles evaluating the antibacterial or antifungal assessment of NEEO were selected. The synthesis of evidence indicates that NEEO are effective in combating multidrug-resistant microorganisms and in the formation of their biofilms. Factors such as NE droplet size, chemical composition of essential oils, and the association of NE with antibiotics are discussed. Furthermore, NEEO showed satisfactory results in vitro and in vivo evaluations against resistant clinical isolates, making them promising for the development of new antimicrobial and antivirulence drugs.

In silico Molecular Docking of Cyclic Peptides against TEM-1 Beta-Lactamases for Effective Antimicrobial Drug Development

Targeting the class A Beta lactamases Omega loop is an ideal way to combat drug resistance because of its significant role in the catalytic activity and deacylation process inhibition. Therefore, the molecular docking approach with computerized peptide-based in silico screening has been applied for the identification of inhibitors of TEM-type βLs. Among the subjected 105 peptides, Chrombacin (-47.8 KJ/mol), Gassericin A (-35.7 KJ/mol), Duramycin (-34.1 KJ/mol), Brevinin-1DYa (-34.0 KJ/mol), Amoebapore A (-31.2 KJ/mol), Mundticin ATO6 (-29.0 KJ/mol), Lactocyclicin Q (-26.3 KJ/mol), Cinnamycin (-25.9 KJ/mol showed highest binding energy. Among the peptides that showed the highest docking score Elafin, Cinnamycin, Duramycin interacted with Lys 73 of the α domain of catalytic residues of TEM-1 Beta lactamases, whereas Taromycin A, Gassericin A interacted with Lys 234 of the β domain, depicting a strong inhibition and also exhibited desirable physicochemical properties. Hence further in vitro examination of these cyclic peptides against the resistant strains is warranted to help design further novel inhibitors based on their scaffolds and also for the development of an effective drug combination regime.

Discovery and Characterization of a Novel Bacteriocin That Strongly Inhibits Staphylococcus aureus

Drug resistance in Staphylococcus aureus is a serious problem, and the development of new antimicrobial drugs to circumvent drug resistance has become a trend. In this study, we isolated a strain of Bacillus subtilis with high tolerance to alcohol, pH, NaCl, bile salt, surfactants, temperature, and simulated intestinal fluids. We optimized culture parameters to obtain the best fermentation conditions for the production of inhibitory compounds in cell-free culture media. The crude extract showed excellent stability when exposed to temperature, pH, and ultraviolet radiation, with almost no loss of bacteriostatic activity after treatment. After isolation and purification, the peptide sequences were identified using ultraperformance liquid chromatography–mass spectrometry (UPLC–MS), and the antibacterial sequences were analyzed using bioinformatics. The results of the identification showed that there was one novel bacteriocin (NSGGSYGSGGGGGGGNSHGY) with a molecular weight of 1513.58 Da. The minimum inhibitory concentration (MIC) of the B5 bacteriocin was 31.25 μg/mL against S. aureus, and it is noteworthy that bacteriocin B5 also showed weak antibacterial activity against Vibrio parahaemolyticus. In conclusion, this study developed a novel bacteriocin that has the potential to be used as an alternative to S. aureus antibiotics.

Photodynamic Inactivation as a Promising Method of Combating Resistant Strains of Staphylococci

Relevance. The development of antimicrobial drugs and alternative methods, technologies and means of prevention, diagnosis and treatment of human infectious diseases caused by antibiotic-resistant microorganisms is one of the priorities of ensuring the biological safety of the country. Aims. To evaluate the bactericidal activity of tetrapyrrole macroheterocycles (porphyrins) at different light irradiation durations in relation to staphylococci, in vitro. Materials and methods. Studied strains of microorganisms: museum strains of microorganisms – S. aureus ATCC 29213, S. epidermidis ATCC 14990 and antibiotic-resistant strains of bacteria of the genus Staphylococcus (n=18) isolated from clinical biomaterial and from environmental objects in a medical organization. The studied chemical compounds are three different compounds of water-soluble asymmetrically substituted porphyrins containing heterocyclic fragments on the periphery of the porphyrin cycle (residues of benzoxazole, N-methylbenzimidazole and benzothiazole). Results. The activity of all three porphyrin compounds in relation to museum strains of staphylococcus and 77.8% of clinical antibiotic-resistant strains (n=14; 95% CI 20.1-97.5) turned out to be maximal (complete lysis) after 10 minutes of irradiation. Conclusions. The tested tetrapyrrole macroheterocycles (porphyrins) exhibit bactericidal activity against museum and clinical strains of staphylococcus, with different levels of antibiotic resistance, which determines Keywords: antibiotic resistance, water-soluble porphyrin, photodynamic inactivation, photosensitizer, photochemistry, staphylococci No conflict of interest to declare.

Rapid and Sensitive Quantification of Bacterial Viability Using Ratiometric Fluorescence Sensing.

Bacterial viability assessment plays an important role in food-borne pathogen detection and antimicrobial drug development. Here, we first used GelRed as a DNA-binding stain for a bacterial viability assessment. It was found that live bacteria were able to exclude GelRed, which however could easily penetrate dead ones and be absorbed nonspecifically on the bacterial periplasm. Cations were used to reduce the nonspecific adsorption and greatly increase the red fluorescence ratio of dead to live bacteria. Combined with SYTO 9 (a membrane-permeable dye) for double-staining, a ratiometric fluorescent method was established. Using Escherichia coli O157:H7 as a bacteria model, the ratiometric fluorescent method can probe dead bacteria as low as 0.1%. A linear correlation between the ratiometric fluorescence and the theoretical ratio of dead bacteria was acquired, with a correlation coefficient R2 of 0.97. Advantages in sensitivity, accuracy, and safety of the GelRed/SYTO9-based ratiometric fluorescent method against traditional methods were demonstrated. The established method was successfully applied to the assessment of germicidal efficacy of different heat treatments. It was found that even 50 °C treatment could lead to the death of minor bacteria. The as-developed method has many potential applications in microbial researches, and we believe it could be expanded to the viability assessment of mammalian cells.

Recreating chronic respiratory infections in vitro using physiologically relevant models.

Despite the need for effective treatments against chronic respiratory infections (often caused by pathogenic biofilms), only a few new antimicrobials have been introduced to the market in recent decades. Although different factors impede the successful advancement of antimicrobial candidates from the bench to the clinic, a major driver is the use of poorly predictive model systems in preclinical research. To bridge this translational gap, significant efforts have been made to develop physiologically relevant models capable of recapitulating the key aspects of the airway microenvironment that are known to influence infection dynamics and antimicrobial activity in vivo In this review, we provide an overview of state-of-the-art cell culture platforms and ex vivo models that have been used to model chronic (biofilm-associated) airway infections, including air-liquid interfaces, three-dimensional cultures obtained with rotating-wall vessel bioreactors, lung-on-a-chips and ex vivo pig lungs. Our focus is on highlighting the advantages of these infection models over standard (abiotic) biofilm methods by describing studies that have benefited from these platforms to investigate chronic bacterial infections and explore novel antibiofilm strategies. Furthermore, we discuss the challenges that still need to be overcome to ensure the widespread application of in vivo-like infection models in antimicrobial drug development, suggesting possible directions for future research. Bearing in mind that no single model is able to faithfully capture the full complexity of the (infected) airways, we emphasise the importance of informed model selection in order to generate clinically relevant experimental data.

Medicinal Efficacy of Tinospora cordifolia, Caesalpinia bonduc and Quercus infectoria Extracts

Medicinal plants have therapeutic value because of the chemical substances present in them. This study was performed to explore the antibacterial and antioxidant potential of three medicinally important plants, such as Caesalpinia bonduc (karanjuwa), Tinospora cordifolia (Giloy), and Quercus infectoria (Majuphal) extract; that are locally used for the cure of various diseases, particularly dengue fever. To study the anti-bacterial, phytochemical and antioxidative potential of these plants, plant extracts were made in ethanol, methanol, and ethyl acetate. Antibacterial assay revealed that all the selected plant extracts of C. bonduc, T. cordifolia, and Q. infectoria variably inhibited the growth of test bacterial strains. The maximum antibacterial activity observed for the ethyl acetate extract of T. cordifolia was against Bacillus (41 mm) and Pseudomonas (38 mm). Phytochemical analysis of extracts of C. bonduc, T. cordifolia, and Q. infectoria revealed the presence of alkaloids, quinones, flavonoids, phenols, and reducing sugars. Antioxidative analysis of the extracts of C. bonduc, T. cordifolia, and Q. infectoria, as revealed by the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay (66%, 62% and 77%), phosphomolybdate (480, 520 and 490 µg/ml), showed ferric reducing antioxidant power (FRAP) assay (266%, 371% and 265%), and total flavonoid content (75%, 170% and 155%) assay. Due to significant antibacterial and antioxidant potential, the extract of T. cordifolia was subjected to Thin-layer chromatography (TLC) analysis that confirmed the presence of different bioactive components in the extract of T. cordifolia (Giloy). Gas Chromatography-Mass spectrophotometry (GCMS) analysis of the bioactive fractions revealed Phthalic acid and Benzene acetic acid as the compounds responsible for imparting good antibacterial and antioxidative potential to the ethyl acetate extract of T. cordifolia. These findings highlight the potential of T. cordifolia as a valuable medicinal plant for the development of future antimicrobial drugs.

In vitro activity of the novel antimicrobial peptide WR-286 in combination with vancomycin against methicillin-resistant Staphylococcus aureus

Background: Multidrug resistance bacteria are a serious problem for health specialists and all the people in the world. The main reasons for this problem are the misuse of antibiotics and the limited number of antibiotics as compared to different human diseases. The important antibiotic-resistant bacteria include Methicillin-resistant Staphylococcus aureus (MRSA). Antimicrobial peptides (AMPs) are regarded as promising antimicrobial agents because they satisfy the requirements for the creation of innovative antimicrobial drugs. The aim of the study: To design a novel antimicrobial peptide and study its effect against MRSA when we combined it with vancomycin. Materials and methods: To produce the hexapeptide WR-286, 1-(2, 6-difluorobenzyl)-1H-1, 2, 3-triazole-4-carboxylic acid, tryptophan (W), and arginine (R) were rationally combined. Different bacterial strains were used to test WR-286's antibacterial properties. Investigations of WR-286's hemolytic activity toward human erythrocytes were also conducted. Finally, utilizing the checkerboard approach and the fractional inhibitory index, synergistic tests with vancomycin were carried out. Results: With MIC values as low as 35 μM, WR-286 demonstrated strong antibacterial activity against MRSA. The toxicity of WR-286 to human red blood cells was very low. Additionally, the peptide and vancomycin's activity were improved by the synergistic experiments. Conclusion: According to the current investigation, WR-286 has little hemolytic activity and displays promising antibacterial activity against MRSA. Additionally, when coupled with vancomycin, the peptide has synergistic effect. The novel AMPs described in this work are promising potential candidates for antimicrobial drug development.

Synthesis, Molecular Docking, and Antimicrobial Evaluation of 2-(Substituted Amino)-N-(6-Substituted-1,3-Benzothiazol-2yl) Acetamide.

The development of antimicrobial agents is crucial for several reasons, primarily to combat infectious diseases and to address the growing threat of antimicrobial resistance. The need for the contin-ued development of antimicrobial drugs persists despite the presence of many existing drugs for several reasons viz; emerging new pathogens and diseases, reistance to existing drug and propogation of multi-drug resistance to existing drugs. The objective of the study was to synthesize and evaluate the antimicrobial potential of newly synthesized benzothiazole derivatives. A new series of 2-(substituted amino)-N-(6-substituted-1,3-benzothiazol-2yl)acetamide BTC(a-t) has been synthesized by reacting it with chloracetyl chloride with substituted 2-amino benzothiazole and further refluxed with various substituted amines to obtain target compounds. The synthesized compounds were screened experimentally for their antimicrobial property against gram-positive and gram-negative bacteria and fungi. The zone of inhibition and minimum inhibitory concentration of compounds were determined against selected bacterial and fungal strains. Further docking study was carried out to check the probable interactions with the selected protein using V-life MDS 3.5 software (DNA gyrase, PDB: 3G75). Compounds BTC-j N-(6-methoxy-1,3-benzothiazol-2-yl)-2-(pyridine-3-ylamino)acetamide and BTC-r N-(6-nitro-1,3-benzothiazol-2-yl)-2-(pyridine-3-ylamino)acetamide were found to have good antimicrobial potential. The compound BTC-j showed good antibacterial activity against S. aureus at an MIC value of 12.5 μg/mL, B. subtilis at MIC of 6.25μg/mL, E. coli at MIC of 3.125μg/mL, and P. aeruginosa at MIC of 6.25μg/mL. Thus, from the result, it was observed that compounds BTC-j, BTC-f, BTC-n, and BTC-r exhibited significant antibacterial and antifungal potential at different concentrations. The present study resulted in the successful synthesis of 2-acetamido substituted benzothiazole derivatives BTC(a-t) with good yields. The dock score of the compounds and the antimicrobial activity were found to be consistent. No statistical difference in the antimicrobial activity of the standard and test compounds was found, indicating that the test compounds have comparable activity. Therefore, benzothiazole linked to heterocyclic rings with an acetamide linkage may serve as promising lead molecules for further optimization in the journey to discover potent antibacterial agents. Thus, we conclude that the synthesized compounds have the potential for further development as novel antimicrobial agents.

Utilization of the Shensheng-Piwen changed medicinal powder extracts combines metal-organic frameworks as an antibacterial agent.

Widespread opportunistic pathogens pose a serious threat to global health, particularly in susceptible hospital populations. The escalating crisis of antibiotic resistance highlights the urgent need for novel antibacterial agents and alternative treatment approaches. Traditional Chinese Medicine (TCM) and its compounds have deep roots in the treatment of infectious diseases. It has a variety of active ingredients and multi-target properties, opening up new avenues for the discovery and development of antimicrobial drugs. This study focuses on assessing the efficacy of the Shensheng-Piwen changed medicinal powder (SPC) extracts against opportunistic pathogen infections by broth microdilution and agar disc diffusion methods. Additionally, biofilm inhibition and eradication assays were performed to evaluate the antibiofilm effects of SPC extracts. Metabolite profiles were analyzed by LC-MS. Furthermore, the potential synergistic effect between SPC and Metal-Organic Framework (MOF) was investigated by bacterial growth curve analysis. The results indicated that the SPC extracts exhibited antibacterial activity against S. aureus, with a minimum inhibitory concentration (MIC) of 7.8 mg/mL (crude drug concentration). Notably, at 1/2 MIC, the SPC extracts significantly inhibited biofilm formation, with over 80% inhibition, which was critical in tackling chronic and hospital-acquired infections. Metabolomic analysis of S. aureus revealed that SPC extracts induced a notable reduction in the levels of various metabolites, including L-proline, L-asparagine. This suggested that the SPC extracts could interfere with the metabolism of S. aureus. Meanwhile, the growth curve experiment proved that SPC extracts and MOFs had a synergistic antibacterial effect. In conclusion, the present study highlights the potential of SPC extracts as a novel antibacterial agent against S. aureus infections, with promising biofilm inhibition properties. The observed synergistic effect between SPC extracts and MOFs further supports the exploration of this combination as an alternative treatment approach.

Biofilm microenvironment-activated multimodal therapy nanoplatform for effective anti-bacterial treatment and wound healing

Antimicrobial drug development faces challenges from bacterial resistance, biofilms, and excessive inflammation. Here, we design an intelligent nanoplatform utilizing mesoporous silica nanoparticles doped with copper ions for loading copper sulfide (DM/Cu2+-CuS). The mesoporous silica doped with tetrasulfide bonds responds to the biofilm microenvironment (BME), releasing Cu2+ions, CuS along with hydrogen sulfide (H2S) gas. The release of hydrogen sulfide within 72 h reached 793.5 µM, significantly higher than that observed with conventional small molecule donors. H2S induces macrophages polarization towards the M2 phenotype, reducing inflammation and synergistically accelerating endothelial cell proliferation and migration with Cu2+ions. In addition, H2S disrupts extracellular DNA within biofilms, synergistically photothermal enhanced peroxidase-like activity of CuS to effectively eradicate biofilms. Remarkably, DM-mediated consumption of endogenous glutathione enhances the anti-biofilm activity of H2S and improves oxygen species (ROS) destruction efficiency. The combination of photothermal therapy (PTT), chemodynamic therapy (CDT), and gas treatment achieves sterilization rates of 99.3 % and 99.6 % against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), respectively, in vitro under 808 nm laser irradiation. Additionally, in vivo experiments demonstrate a significant biosafety and antibacterial potential. In summary, the H2S donor developed in this study exhibits enhanced biocompatibility and controlled release properties. By integrating BME-responsive gas therapy with antibacterial ions, PTT and CDT, a synergistic multimodal strategy is proposed to offer new therapeutic approaches for wound healing. Statement of significanceThe advanced DMOS/Cu2+-CuS (DMCC) multimodal therapeutic nanoplatform has been developed for the treatment of drug-resistant bacterial wound infections and has exhibited enhanced therapeutic efficacy through the synergistic effects of photothermal therapy, chemodynamic therapy, Cu2+ions, and H2S. The DMCC exhibited exceptional biocompatibility and could release CuS, Cu2+, and H2S in response to elevated concentrations of glutathione within the biofilm microenvironment. H2S effectively disrupted the biofilm structure. Meanwhile, peroxidase activity of CuS combined with GSH-mediated reduction of Cu2+ to Cu+ generated abundant hydroxyl radicals under acidic conditions, leading to efficient eradication of pathogenic bacteria. Furthermore, both H2S and Cu2+ could modulate M2 macrophages polarization and regulate immune microenvironment dynamics. These strategies collectively provided a novel approach for developing antibacterial nanomedical platforms.