Antibacterial Compounds Research Articles

Gradual Acidification at the Oral Biofilm-Implant Material Interface.

The colonization of dental implants by oral biofilms causes inflammatory reactions that can ultimately lead to implant loss. Therefore, safety-integrated implant surfaces are under development that aim to detect bacterial attachment at an early stage and subsequently release antibacterial compounds to prevent their accumulation. Since primary oral colonizers ferment carbohydrates leading to local acidification, pH is considered a promising trigger for these surfaces. As a prerequisite for such systems, the present study aimed at specifically analyzing the pH at the interface between implant material and oral biofilms. For this purpose, in vitro-grown Streptococcus oralis monospecies biofilms and an established multispecies biofilm on titanium discs as well as in situ-grown biofilms from orally exposed titanium-equipped splints were used. Mature biofilm morphology was characterized by live/dead fluorescence staining, revealing improved growth from in vitro to in situ biofilms as well as a general decreasing membrane permeability over time due to the static incubation conditions. For pH analysis, the pH-sensitive dye C-SNARF-4 combined with 3-dimensional imaging by confocal laser-scanning microscopy and digital image analysis were used to detect extracellular pH values in different biofilm layers. All mature biofilms showed a pH gradient, with the lowest values at the material interface. Interestingly, the exact values depicted a time- and nutrient-dependent gradual acidification independently of the biofilm source and for in situ biofilms also independently of the sample donor. After short incubation times, a mild acidification to approximately pH 6.3 could be observed. But when sufficient nutrients were processed for a longer period of time, acidification intensified, leading to approximately pH 5.0. This not only defines the required turning point of pH-triggered implant release systems but also reveals the opportunity for a tailored release at different stages of biofilm formation.

Gatifloxacin hydrochloride confers broad-spectrum antibacterial activity against phytopathogenic bacteria

Bacterial diseases pose significant threats to agriculture and natural ecosystems, causing substantial crop losses and impacting food security. Until now, there has been a less efficient control strategy against some bacterial diseases such as bacterial wilt, caused by Ralstonia solanacearum. In this study, we screened a library of 58 microorganism-derived natural products for their antibacterial activity against R. solanacearum. Gatifloxacin hydrochloride exhibited the best inhibitory effect with an inhibition rate of 95% at 0.0625 mg/L. Further experiments demonstrate that gatifloxacin hydrochloride inhibits R. solanacearum growth in a concentration-dependent manner, with the minimum inhibitory concentration of 0.125 mg/L. Treatment with 0.5 mg/L of gatifloxacin hydrochloride killed more than 95% of bacteria. Gatifloxacin hydrochloride significantly inhibited biofilm formation by R. solanacearum. Gatifloxacin hydrochloride also shows good antibacterial activity against Pseudomonas syringae pv. tomato DC3000 and Xanthomonas campestris pv. vesicatoria. Exogenous application of gatifloxacin hydrochloride suppressed disease development caused by R. solanacearum and P. syringae. In summary, our results demonstrate the great potential of microorganism-derived compounds as broad-spectrum antibacterial compounds, providing alternative ways for the efficient control of bacterial plant diseases.

Why do pacifiers/dummies have a protective effect in sudden infant death Syndrome? A new hypothesis

The American Academy of Pediatrics recommends pacifier/dummy use to help prevent sudden infant death syndrome (SIDS). This recommendation is based on studies that have shown pacifier use reduces the risk of SIDS even under conditions regarded as increasing the risk of SIDS. Several unrelated mechanistic explanations have been used to explain this. These prior suggested mechanisms purported to underly the observed protective effect of pacifiers have not proven satisfactory and highlight the need for a more plausible explanation. Pacifier use is associated with increased salivary production. Saliva contains numerous antibacterial compounds that could provide a protective effect against bacterial colonisation. Infection is considered a key player in SIDS pathogenesis given that most SIDS risk factors relate to or align with infection, whereas mainstream research focusses on central homeostatic control of breathing, arousal and heart function. These, however, lack association with risk factors. Given infection is significant in the SIDS story, the increased production and antibacterial effect of saliva could provide an alternative mechanism worthy of consideration in the context of known preventable risk factors in the drive to reach a better understanding of SIDS pathogenesis and further decrease the incidence of SIDS.

An in-silico approach to target multiple proteins involved in anti-microbial resistance using natural compounds produced by wild mushrooms

Bacterial resistance to antibiotics and the number of patients infected by multi-drug-resistant bacteria have increased significantly over the past decade. This study follows a computational approach to identify potential antibacterial compounds from wild mushrooms. Twenty-six known compounds produced by wild mushrooms were docked to assess their affinity with drug targets of antibiotics such as penicillin-binding protein-1a (PBP1a), DNA gyrase, and isoleucyl-tRNA synthetase (ILERS). Docking scores were further validated by multiple receptor conformer (MRC)-based docking studies. Based on the MRC-based docking results, eight molecules were shortlisted for ADMET analysis. Molecular dynamics (MD) simulations were further performed to evaluate the conformational stability of the ligand-protein complexes. Binding energies were computed by the gmx_MMPBSA method. The data were obtained in terms of root-mean square deviation, and root-mean square fluctuation justified the stability of Austrocortilutein A, Austrocortirubin, and Confluentin in complex with several proteins under physiological conditions. Among these, Austrocortilutein A displayed better binding affinity with PBP1a and ILERS when compared with their respective reference ligands. This study is preliminary and aims to help drive the search for compounds that have the capacity to overcome the anti-microbial resistance of prevalent bacteria, using natural compounds produced by wild mushrooms. Further experimental validation is required to justify the clinical use of the studied compounds.

Nature-Inspired Antimicrobial Agents: Cinnamon-Derived Copper Oxide Nanoparticles for Effective Aspergillus Niger Control.

The emergence of resistant bacterial and fungal strains poses significant challenges in various industrial processes including food, medicines, and leather industry. It necessitates the development of novel and effective antimicrobial agents. In the present work, we have developed an ecofriendly and sustainable approach to synthesize silver-doped copper oxide nanoparticles by using cinnamon bark extract (C-CuO/Ag). The nanoparticles were characterized via UV-visible spectroscopy at 190-800 nm, FT-IR, SEM-EDAX, XRD, and further subjected to determine antimicrobial potential, minimum inhibitory concentration (MIC), and anti-biofilm potential against both bacterial and fungal species. UV-visible spectrum showed maximum absorption at 210 nm in ultraviolet range and 419 nm in visible range. Various strong and weak peaks were obtained in FT-IR spectra, which defined the presence of corresponding functional groups in C-CuO/Ag nanoparticles. SEM analysis revealed the tightly packed confirmation, while EDS confirmed the elemental analysis of C-CuO/Ag nanoparticles. XRD spectrum of C-CuO/Ag nanoparticles showed strong diffraction peaks at 2Ө of 31.92˚, 35.67˚, and 48.51˚, which confined with the plane indices of (-110), (111), and (-202), respectively, while weak diffraction peaks at 2Ө of 56.31˚, 58.9˚, and 77.4˚, which leads to the crystal planes of (202), (-220), and (311), respectively. Antimicrobial assays showed clear zones of inhibition against microbial strains as maximum inhibition diameter was observed against Aspergillus niger (31.5 ± 0.7 mm) followed by Escherichia coli (30.1 ± 0.3 mm) and Staphylococcus aureus (29.5 ± 0.7 mm). These findings provide support clear evidence that CuO nanoparticles can serve as potent antibacterial and antifungal compounds against highly resistive and pathogenic microbial strains.

Lichen and its Microbiome as an Untapped Source of Anti-biofilm Compounds.

Lichen substances have been firstly described in the 1870s and most of them have been evaluated for their activity on planktonic microorganisms (bacteria and fungi). More recently, microorganisms colonizing the lichen thallus have been isolated and identified giving access to a wild diversity of culturable microorganisms. The increasing research in lichens associated microbiome in recent years, has emphased a wide range of metabolites as a potential source of bioactive compounds. In parallel, humans are facing microbial resistance to conventional antimicrobial drugs. One of the reasons is the biofilm lifestyle of microorganisms. Indeed, the aggregation of microbial communities inside biofilms is now well-known and characterized and some possible ways to fight and destroy biofilms are identified (quorum sensing inhibitors,…). The present review aims to summarize the anti-biofilm potential of lichen metabolites and those from their associated microorganisms (bacteria and/or fungi). Are the metabolites isolated from lichens and their associated fungi displaying any anti-biofilm activity? This literature synthesis highlights the metabolites of interest as new anti-biofilm drugs and shows the lack of current biological research dealing with biofilm and lichen metabolites. Only two lichen metabolites, usnic acid and evernic acid, have been evaluated both as antifungal and antibacterial biofilm compounds.

Unleashing the Power of Artificial Intelligence-Driven Drug Discovery in Streptomyces

The rise of antibiotic resistance has created an urgent need for the discovery of new antibiotic compounds. Streptomycin, the first antibiotic isolated from Streptomyces sp., paved the way for discovering other antibiotics for combating bacterial infections. By exploring the genome-based biosynthetic potential of various Streptomyces species, a vast array of secondary metabolites with potential therapeutic applications can be identified, contributing a transformative impact on the field of medicine. However, conventional screening approaches on novel natural products (NPs) from Streptomyces sp. have entered a bottleneck due to inefficiency. Fortunately, artificial intelligence (AI) and machine learning (ML) models enable rapid exploration and prediction of potential antibiotic compounds, increasing the probability of discovering new antibacterial compounds. AI-driven drug discovery in Streptomyces sp. represents a paradigm shift in the future quest for novel pharmaceutical agents. Various ML models have been developed and applied in different practical applications. Overall, the ML model is trained using input data and generates outcomes based on prediction output. This review discusses the continued potential of Streptomyces sp. as a source of novel NPs, along with the application of ML throughout the NP drug discovery pipeline involving genome mining, biological activities prediction, and optimization compound production in Streptomyces microbial systems. Graphical abstract: The role of machine learning in drug discovery from Streptomyces

Preparation and kinetic studies of a new antibacterial sodium alginate gelatin hydrogel composite.

This study involved synthesis of a novel antibacterial heterocyclic compound, sodium 2-(2-(3-phenyl-1, 2, 4-oxadiazol-5-yl) phenoxy) acetate abbreviated as Na-POPA. Further development of a biocompatible, pH-responsive hydrogel drug carrier prepared utilizing the natural polymers gelatin and sodium alginate. The compound loaded on the hydrogel represented new drug delivery system. Comprehensive characterization of Na-POPA was performed using Fourier-transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (¹H NMR), carbon-13 nuclear magnetic resonance (¹³C NMR), and high-resolution mass spectrometry (HRMS). The compound was loaded onto the sodium alginate/gelatin hydrogel carrier under feasible experimental conditions. The successful incorporation of Na-POPA into the hydrogel matrix was confirmed via scanning electron microscopy (SEM), powder X-ray diffraction (pXRD) analysis and FT-IR spectroscopy. Cytotoxicity assays revealed that the all the loaded and unloaded compound induced cell toxicity at large concentration much lower than many reported results. The hydrogel reduced the inherent cytotoxicity of Na-POPA and enhanced its biocompatibility. The release kinetics of Na-POPA from the hydrogel were evaluated spectrophotometrically at different pH conditions simulating biological fluids. The release rate at pH 1.2 was greater than the release at pH 6.8, with a higher cumulative release observed at pH 6.8. The release kinetics obeyed the pseudo-second-order kinetic model, indicating a controlled release mechanism influenced by the hydrogel's physicochemical properties. Electrochemical impedance spectroscopy and cyclic voltammetry further confirmed that the compound release was pH-dependent. The high swelling and solubility at pH 6.8 enhance the release. The larger amount released at 6.8 (target intestine) because of more solubility, leaching and swelling rather than shrinking.

Assessing Normandy Soil Microbial Diversity for Antibacterial Activities Using Traditional Culture and iChip Methods

Uncultured microorganisms represent a promising and untapped source of antibacterial compounds, crucial in the fight against the significant threat of antimicrobial resistance (AMR). In this study, both traditional and isolation chip (iChip) cultivation techniques were employed to enhance the recovery of known and unknown microorganisms from soils located in Normandy, France. The isolates obtained were identified using 16S rDNA or ITS regions analysis and MALDI-TOF mass spectrometry and were screened for antibacterial activity. A total of 386 isolates, belonging to 6 microbial phyla and distributed across 65 genera, were recovered using both methods. In total, 11 isolates are potentially new bacterial species, and 34 were associated with 22 species described recently. The iChip method yielded a higher diversity of microorganisms (47 genera) than the traditional method (38 genera) and was particularly effective in enriching Actinomycetota. Antibacterial screening against target bacteria showed that 85 isolates (22%) exhibited antibacterial activity. The Streptomyces, Pseudomonas, and Bacillaceae taxa accounted for most antibacterial-producing bacteria with some presenting promising undescribed characteristics. Other active isolates were affiliated with less-known antibacterial producers such as Arthrobacter, Chryseobacterium, Delftia, Ensifer, Flavobacterium, Rahnella, and Stenotrophomonas, among others. These results highlight the potential of our microbial collection as a source of new antibacterial natural products.

Behavioural, Teratogenic and Genotoxic Effects of Antibacterial Compounds, Triclocarban and Triclosan, in Hydra vulgaris.

Triclocarban (TCC) and triclosan (TCS) are antibacterial compounds used in household, veterinary, industrial and personal care products, which are known to be environmental pollutants and also toxic to organisms. The toxicological effects of these antibacterial chemicals on higher organisms have been studied in detail. But in lower invertebrates like hydra, it is still rare and yet to be explored. In this study, the toxicological effects of these two antibacterial compounds in Hydra vulgaris was performed to clearly understand the organismal, developmental, molecular and behavioural changes. Both TCC and TCS are toxic with respective LC50 values of 0.09 and 0.25 mg/L, whereas TCC is comparatively more toxic than TCS. The structural damage of battery cell complexes (BCCs) on the tentacles was observed and ultimately made prey capturing difficult. It was evident that TCC and TCS exposure caused developmental toxicity by affecting reproduction and regeneration in H. vulgaris at higher sublethal doses (0.045 and 0.125 mg/L, respectively). TCC and TCS also caused DNA damage resulting in apoptosis. This study further reveals that these two antibacterial compounds are teratogenic and genotoxic in the organisms.

Effects of Perillaldehyde and Polyamines on Defense Mechanisms of Sweet Potatoes against Ceratocystis fimbriata.

Sweet potato (Ipomoea batatas) serves as a significant food and economic crop worldwide. However, its production and safety are jeopardized by black rot, a disease caused by Ceratocystis fimbriata. Although polyamines (PAs) are common biological growth factors, their function in the storage of fruits and vegetables remains poorly understood. This study examines the physiological roles of both exogenous and endogenous PAs in C. fimbriata, particularly their metabolism via gene knockout techniques. Additionally, we assessed how exogenous PAs affect sweet potato storage resistance. Our findings reveal that PAs are crucial in managing oxidative and cell wall stress in C. fimbriata. At high concentrations, PAs displayed cytotoxic effects through the upregulation of nitric oxide synthase (TAH18). Furthermore, exogenous PAs significantly enhanced the defense mechanisms of sweet potatoes during storage. The concurrent use of perillaldehyde (PAE), a natural antibacterial compound, additionally decreased the incidence of black rot in sweet potatoes. This study provides a novel strategy and theoretical basis for the prevention and control of fungal diseases in stored fruits and vegetables.

Therapeutic Potential of Silver Nanoparticles (AgNPs) as an Antimycobacterial Agent: A Comprehensive Review.

The uncontrolled emergence of multidrug-resistant mycobacterial strains presents as the primary determinant of the present crisis in antimycobacterial therapeutics and underscores tuberculosis (TB) as a daunting global health concern. There is an urgent requirement for drug development for the treatment of TB. Numerous novel molecules are presently undergoing clinical investigation as part of TB drug development. However, the complex cell wall and the lifecycle of M. tuberculosis within the host pose a significant challenge to the development of new drugs and, therefore, led to a shift in research focus towards alternative antibacterial compounds, notably nanotechnology. A novel approach to TB therapy utilizing silver nanoparticles (AgNPs) holds the potential to address the medical limitations imposed by drug resistance commonly associated with currently available antibiotics. Their broad-spectrum antimicrobial activity presents the utilization of AgNPs as a promising avenue for the development of therapeutics targeting mycobacterial-induced diseases, which can effectively target Mycobacterium tuberculosis, including drug-resistant strains. AgNPs can enhance the effectiveness of traditional antibiotics, potentially leading to better treatment outcomes and a shorter duration of therapy. However, the successful implementation of this complementary strategy is contingent upon addressing several pivotal therapeutic challenges, including suboptimal delivery, variability in intra-macrophagic antimycobacterial effect, and potential toxicity. Future perspectives may involve developing targeted delivery systems that maximize therapeutic effects and minimize side effects, as well as exploring combinations with existing TB medications to enhance treatment outcomes. We have attempted to provide a comprehensive overview of the antimycobacterial activity of AgNPs, and critically analyze the advantages and limitations of employing silver nanoparticles in the treatment of TB.

Natural Antibacterial Compounds with Potential for Incorporation into Dental Adhesives: A Systematic Review

Dental adhesives are essential in modern restorative dentistry and are constantly evolving. However, challenges like secondary caries from bacterial infiltration at the adhesive–tooth interface persist. While synthetic antibacterial agents in adhesives show promise, safety concerns have shifted interest toward natural options that are biocompatible, sustainable, and effective. Therefore, this study evaluated whether natural antibacterial compounds in dental adhesives can provide effective antimicrobial activity without compromising their integrity. This systematic review followed PRISMA 2020 statement guidelines. Four databases were screened, PubMed, Scopus, EMBASE, and Web of Science, without language or publication date restrictions until July 2024. The selection criteria were in vitro studies in which natural antimicrobial substances were incorporated into dental adhesives and the resulting composites were tested for their antibacterial and physicochemical properties. A quality assessment was conducted on the selected studies. Most of the studies reviewed reported significant antibacterial activity while retaining the adhesive’s integrity, generally achieved with lower concentrations of the natural agents. Higher concentrations increase the antimicrobial effectiveness but negatively impact the adhesive’s properties. This review highlights the promising role of natural antibacterial compounds in enhancing the functionality of dental adhesives while also pointing to the need for continued research to address current challenges.

Selective production of the itaconic acid-derived compounds 2-hydroxyparaconic and itatartaric acid

There is a strong interest in itaconic acid in the medical and pharmaceutical sectors, both as an anti-bacterial compound and as an immunoregulator in mammalian macrophages. Fungal hosts also produce itaconic acid, and in addition they can produce two derivatives 2-hydroxyparaconic and itatartaric acid. Not much is known about these two derivatives, while their structural analogy to itaconate could open up several applications. In this study, we report the production of these two itaconate-derived compounds. By overexpressing the itaconate P450 monooxygenase Cyp3 in a previously engineered itaconate-overproducing Ustilago cynodontis strain, itaconate was converted to its lactone 2-hydroxyparaconate. The second product itatartarate is most likely the result of the subsequent lactone hydrolysis. A major challenge in the production of 2-hydroxyparaconate and itatartarate is their co-production with itaconate, leading to difficulties in their purification. Achieving high derivatives specificity was therefore the paramount objective. Different strategies were evaluated including process parameters such as substrate and pH, as well as strain engineering focusing on Cyp3 expression and product export. 2-hydroxyparaconate and itatartarate were successfully produced from glucose and glycerol, with the latter resulting in a higher derivatives specificity due to an overall slower metabolism on this non-preferred carbon source. The derivatives specificity could be further increased by metabolic engineering approaches including the exchange of the native itaconate transporter Itp1 with the Aspergillus terreus itaconate transporter MfsA. Both 2-hydroxyparaconate and itatartarate were recovered from fermentation supernatants following a pre-existing protocol. 2-hydroxyparaconate was recovered first through a process of evaporation, lactonization, and extraction with ethyl acetate. Subsequently, itatartarate could be obtained in the form of its sodium salt by saponification of the purified 2-hydroxyparaconate. Finally, several analytical methods were used to characterize the resulting products and their structures were confirmed by nuclear magnetic resonance spectroscopy. This work provides a promising foundation for obtaining 2-hydroxyparaconate and itatartarate in high purity and quantity. This will allow to unravel the full spectrum of potential applications of these novel compounds.

Riddelline from Tamarix articulate as a potential anti-bacterial lead compound for novel antibiotics discovery: A comprehensive computational and toxicological studies.

Tamarix articulate from the Tamaricaece family is a halophytic plant. This plant is commonly called Athal or Tamarix in different Arabic and Asian countries. Due to the high load of polyphenolic phytochemicals, the plant has been used as a therapeutic option against several diseases for decades. The plant is an anti-inflammatory, anti-bacterial, anti-viral, anti-cancer, anti-oxidant, and anti-inflammatory. In this work, the 222 phytochemical compounds of T. articulate from our previous study are used in different bioinformatic and biophysics techniques to explore their biological potency against different anti-bacterial, anti-cancer and anti-viral targets. By doing so, it was found that Riddelline ranked as the best binding molecule of biological macromolecules selected herein in particular the bacterial targets. The binding energy value of the compound for the KdsA enzyme was -14.64 kcal/mol, KdsB (-13.09 kcal/mol), MurC (-13.67 kcal/mol), MurD (-13.54 kcal/mol), MurF (-14.20 kcal/mol), Polo-like kinase 1 (Plk1) (-12.34 kcal/mol), Bcl-2 protein (-13.39 kcal/mol), SARS-CoV-2 main protease enzyme (-12.67 kcal/mol), and Human T cell leukemia virus protease (-13.67 kcal/mol). The mean Rg value of KdsA-Riddelline complex and KdsA-FPE complex is 32.67 Å, and average RMSD of KdsA-Riddelline complex and KdsA-FPE complex is 2.31 Å, respectively. The binding energy complexes was found to be dominated by van der Waals (-71.98 kcal/mol for KdsA-Riddelline complex and -65.09 kcal/mol for KdsA-FPE complex). The lead compound was also unveiled to show favorable druglike properties and pharmacokinetics. Together, the data suggest the good anti-bacterial activities of the T. articulate phytochemicals and thus can be subjected to experimental in vitro and in vivo investigations.

Characterization of Antibacterial Compounds from Marine Sponge-associated Streptomyces spp. against Some Pathogenic Bacteria

The increasing trend of antibiotic resistance among pathogenic bacteria is a worldwide problem. Streptomyces produce a number of bioactive compounds such as antibacterial. This study aimed to investigate the effect of different media and incubation time in increasing the antibacterial activity of marine sponge-associated Streptomyces spp. and characterize antibacterial compounds of marine sponge-associated Streptomyces spp. against pathogenic bacteria. Among the three tested media and some days of incubation times, Streptomyces spp. produce more antibacterial activity when grown using modified molasses medium at 15 days incubation. The ethyl acetate extracts of Dbi28t exhibited a significant inhibitory zone against Extended Spectrum β-Lactamase (ESBL)-producing Escherichia coli, Providencia rettgeri then followed by Proteus mirabilis and Pseudomonas putida and the results were higher than some commercial antibiotics. This study has identified nine antibacterial compounds in Dbi28t using Liquid Chromatography-tandem Mass Spectrometric (LC-MS/MS) analysis, with the most abundance belonging to pumilacidin A, then followed by pumilacidin B, surfactin B, surfactin A, phenazostatin B, chalcomycin B, neopyrrolomycin C, saquayamycin A and saphenamycin. This work provides the first report from a Streptomyces sp. Dbi28t produced pumilacidin, surfactin and other bioactive compounds with the modified molasses medium for optimization of characterization of its antibacterial compounds.

Surface-functionalized UIO-66-NH2 for dual-drug delivery of vancomycin and amikacin against vancomycin-resistant Staphylococcus aureus

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

Establishment and application of highly efficient regeneration, genetic transformation and genome editing system for cucurbitacins biosynthesis in Hemsleya chinensis

Background Hemsleya Chinensis is a perennial plant in the Cucurbitaceae family containing antibacterial and anti-inflammatory compounds. The lack of genetic transformation systems makes it difficult to verify the functions of genes controlling important traits and conduct molecular breeding in H. chinensis.ResultsHighly efficient calli were induced on MS medium added 1.5 mg·L− 1 6-benzylaminopurine (6-BA) and 0.02 mg·L− 1 1-naphthylacetic acid (NAA) with high efficiency (> 95%). The frequency of shoot induction was increased to 90% with a plant growth regulator combination of 1.5 mg·L− 1 6-BA and 0.1 mg·L− 1 NAA. Our results also showed that 100% of shoot regeneration was achieved in a shoot regeneration medium. Additionally, more than 92% of kanamycin-resistant plants were confirmed. Furthermore, we achieved 42% genome editing efficiency by applying this transformation method to HcOSC6, a gene that catalyzes the formation of cucurbitadienol. HPLC analysis showed OE-HcOSC6 lines exhibited significantly higher cucurbitadienol levels than the genome-edited lines. Transcriptomic analysis revealed that some downstream genes related to cucurbitadienol biosynthesis, such as HcCYP87D20, HcCYP81Q58, and HcSDR34, were up-regulated in OE lines and down-regulated in mutants.ConclusionsHere, we established a process for regeneration, transformation, and genome editing of H. chinensis using stem segments. This provides valuable insight into the underlying molecular mechanisms of medicinal compound production. By combining high-efficiency tissue culture, transformation, and genome editing systems, we provide a powerful platform that supports functional research on molecular mechanisms of secondary metabolism.

The Effectiveness of Herbal Mouthwash with Mangosteen Peel Extract in Inhibiting Dental Plaque Formation

Abstract Objective Dental plaque control is important for preventing periodontal tissue diseases. Dental plaque control therapy is enhanced when supported by adjunctive therapy, including the use of mangosteen peel extract mouthwash. Mangosteen peel extract contains α-mangostin, saponins, alkaloids, tannins, flavonoids, quinones, and triterpenoids, which have antibacterial properties against bacteria that cause dental plaque. This study aims to determine the effectiveness of mangosteen peel extract mouthwash at concentrations of 2, 4, and 6% in inhibiting plaque formation. Materials and Methods The study used a quasi-experimental design with pre- and posttreatment examinations. Samples were taken using purposive sampling on 32 patients of Periodontology Clinic of Padjadjaran University Dental Hospital. The patients underwent prophylactic treatment (scaling), then the dental plaque index was measured using the Q-ray Cam Pro and the Loe and Silness Index before (day 1) and after (day 3) gargling with distilled water or mangosteen peel extract mouthwash at concentrations of 2, 4, and 6% for 2 days without oral hygiene in the maxillary area. The data were analyzed using the Wilcoxon test, analysis of variance (ANOVA), and the Kruskal–Wallis test. Results A phytochemical analysis revealed that the mangosteen peel extract contains antibacterial compounds such as flavonoids, saponins, polyphenols, quinones, and triterpenoids. The mangosteen peel extract mouthwash group exhibited lower mean differences in plaque index compared with the aquades group. The 2% mangosteen peel extract mouthwash shows the smallest mean difference of 0.25 in the Q-ray Cam Pro examination and 0.062 in the Loe and Silness Index examination. Conclusion Mouthwash with 2, 4, and 6% mangosteen peel extract has an effect in inhibiting dental plaque formation, with 2% concentration exhibiting the best inhibitory effect on dental plaque formation.

Genomic characterization and probiotic potency of Bacillus velezensis CPA1-1 reveals its potential for aquaculture applications

Biological prevention and control are increasingly applied in sustainable aquaculture, and Bacillus spp. has been revealed to good alternatives to antibiotics. This research examined the probiotic capabilities of Bacillus velezensis CPA1-1 by genomic and phenotypic analysis. The genome sequence showed that B. velezensis CPA1-1 has a 3,925,520 bp chromosome with 46.49 % GC content and 3762 CDSs. And eight clusters of secondary metabolite biosynthesis genes related to antibacterial compounds were predicted in CPA1-1 genome, including surfactin, difficidin, bacillibactin, fengycin, bacilysin, bacillaene, macrolactin H, butirosin A. Besides, the antimicrobial assay indicated that strain CPA1-1 exhibited strong antagonistic capacity against non-O1/O139 Vibrio cholerae GXFL1-4 isolated from diseased Macrobrachium rosenbergii, and MIC of CPA1-1 fermentation broth against GXFL1-4 was 1.0 × 105 CFU/mL. Furthermore, administering CPA1-1 markedly elevated the activities of ACP, AKP, and SOD in M. rosenbergii, and the immune-related genes, including ALF, Crustin, Hemocyanin, Prophenoloxidase, C-type lectin and HSP70, also exhibited higher expression in the CPA1-1 treated groups. Additionally, M. rosenbergii in the test group treated with CPA1-1 could resist non-O1/O139 V. cholerae GXFL1-4 infection by the challenge test. Our study contributed to reveal biocontrol mechanisms of B. velezensis CPA1-1, and demonstrated that CPA1-1 has promise as a probiotic agent for aquaculture.