Problem Of Resistance Research Articles

Study of Amino Acid-Derived 3-Acyltetramic Acids as Herbicidal Agents.

The growing problem of herbicide resistance necessitates the development of novel herbicidal active ingredients, together with other integrated weed management approaches. Natural products are a major source of inspiration for novel actives. In previous research, we identified a 3-acyltetramic acid of microbial origin that inhibited algal growth in marine biofilms, at least in part through inhibition of photosystem II. In this work, we demonstrate the herbicidal effect of this lead compound and construct multiple libraries to test the impact of the different substituents of the central scaffold in order to study the structure-activity relationships. Among these analogues, the highest activities were found for medium- to long-chain acyl groups and apolar secondary amino acid residues. Finally, we provide first insights into the herbicidal mechanisms and present preliminary field-trial and ecotoxicological results for TA12-Pro, the most active analogue in our library. Together, this research shows the potential of 3-acyltetramic acids for herbicide development.

Biodegradable magnesium based metal materials inhibit the growth of cervical cancer cells

Traditional chemotherapy drugs for cervical cancer often cause significant toxic side effects and drug resistance problems, highlighting the urgent need for more innovative and effective treatment strategies. Magnesium alloy is known to be degradable and biocompatible. The release of degradation products Mg2+, OH−, and H2 from magnesium alloy can alter the tumor microenvironment, providing potential anti-tumor properties. We explored the innovative use of magnesium alloy biomaterials in the treatment of cervical cancer, investigating how various concentrations of Mg2+ on the proliferation and cell death of cervical cancer cells. The results revealed that varying concentrations of Mg2+ significantly inhibited cervical cancer by arresting the cell cycle in the G0/G1 phase and inducing apoptosis in SiHa cells, effectively reducing tumor cell proliferation. In vivo experiments demonstrated that 20 mM Mg2+ group had the smallest tumor volume, exhibiting a potent inhibitory effect on the biological characteristics of cervical cancer. This enhances the therapeutic potential of this biomaterial as a local anti-tumor therapy and lays a theoretical foundation for the potential application of magnesium in the treatment of cervical cancer.

Pharmacies Counselling of Patients in the Era of Antifungal Resistance.

Tinea pedis is one of the most prevalent superficial fungal infections. Initial antifungal treatment is often acquired over-the-counter (OTC) without previous consultation with a physician. Lately, increasing antifungal terbinafine resistance has been documented in Denmark and globally and it is therefore of interest to assess how Danish pharmacies advise customers with tinea pedis. One hundred Danish pharmacies were randomly selected and an employee interviewed from each. A structured question guide was followed, with the possibility to add further comments. Interviews of 94 pharmacies were conducted. Six pharmacies never replied. Terbinafine as standard dose or cutaneous solution terbinafine one time application (Lamisil Once (R)) were recommended by 99% of the pharmacy employees as first-line treatment. The customer was advised to seek medical attention when tinea pedis was recurring (93%), or when treatment duration was > 2 weeks (77%). The majority (88%) of the pharmacy employees had no knowledge about antifungal resistance. Only few pharmacy employees were aware of the current problem of antifungal resistance and the majority advised costumers to initiate treatment using OTC topical terbinafine. The problem of emerging antifungal resistance requires attention in order to provide customers with tinea pedis effective treatment and prevent further societal spread of resistance to antifungals.

Effect of feeding chitosan and blend of essential organic acids on growth performance, haematological parameters and innate immunity in early aged male layer chicks.

The use of antibiotics as conventional feed additives in poultry operations have proven useful, however resulted serious health concerns to consumer due to their bio-accumulation, besides rising problem of antimicrobial resistance in microbes, thus, an alternative to antibiotic growth promoter have called for. One of the aim of the experiment was to assess the lone and combined effects of feeding of chitosan oligosaccharide (COS) and blend of organic acids and short chain fatty acids in essential oils on growth performance, haematological parameters, relative lymphoid organ weight and innate immunity in early aged layer chick(male birds). A total of ninety, day-old chicks were randomly allotted into five groups: CO, Control group fed only poultry feed ; AGP, antibiotic growth promoter fed Avilomycin at the dose of 200mg/kg of poultry feed; CH, chitosan oligosaccharide fed at the rate of 100mg/kg feed; OE, blend of organic acids and short chain fatty acids in essential oils contained 1000 to 2000mg/kg feed in a graded dose per week and CH + OE, chitosan oligosaccharide plus blend of organic acids and short chain fatty acids in essential oils at consistent rate and manner as followed for each of given feed additives when fed individually. Data on growth performance, samples for haematological parameters and innate immunity were measured and assayed on 7th, 21st and 42nd day post feeding (dpf) respectively. The results showed that compared with the control group; there is a marginal gain in body weight at 7th and 21st dpf in CH group and the corresponding CH + OE group. Feed conversion ratio in CH group was remarkably good at 7th and 21st dpf. No significant difference was observed in relative organ weights of thymus, spleen and Bursa of Fabricius in treatment groups as compared to control birds; however a significant rise in splenic weight index in OE fed birds at 42nd dpf noted. Haematological changes were inconsequential in treatment groups with an exception to enhancement of heterophil to lymphocyte ratio (H:L ratio) in CH group at 42nd dpf. Serum lysozyme activity proportionately elevated in CH + OE group on 21st and 42nd dpf when measured against control group; on the other hand no detectable augmentation of gut lysozyme activity observed. Both serum bactericidal and gut bactericidal activity boosted in combinatorial group at 42nd dpf. These results indicated that early age feeding of chitosan individually or combination with organic acids and short chain fatty acids in layer chick is beneficial, as it has the potential to enhance body weight gain to some extent and improves systemic and localized innate immunity to offer protection against infectious assaults thus may avoid early chick mortality in farms.

Chinese expert consensus on management of antifungal-resistant dermatophytoses (2024 edition).

Antifungal-resistant dermatophytes (ARD) infection is a hotspot issue in clinical microbiology and the dermatology field. Trichophyton indotineae as the dominant species of dermatophyte with terbinafine-resistance or multidrug resistance, is easy to be missed detection clinically, which brings severe challenges to diagnosis and treatment. ARD infection cases have emerged in China, and it predicts a risk of transmission among human. Based on the existing medical evidence and research data, the Mycology Group of Combination of Traditional and Western Medicine Dermatology and Chinese Antifungal⁃Resistant Dermatophytoses Expert Consensus Group organized experts to make consensus on the management of the infection. Here, the consensus formulated diagnosis and treatment recommendations, to raise attention to dermatophytes drug resistance problem, and expect to provide reference information for the clinical diagnosis, treatment, prevention and control.

Neutral red/carbon dots photodynamic disinfectant spray for sports mouthguards cleaning and perishable foods preservation

Bacterial contamination of medical devices and food poses critical threat to mankind's health. Although some antibiotics can kill bacteria, their mis/overuse in healthcare and agriculture has brought about serious bacterial antibiotic resistance. Thus, developing a convenient and rapid sterilization method becomes increasingly important. Herein, the nanocomposite NR@CDs was synthesized by the assembly of neutral red (NR) with carbon dots (CDs). Compared with NR, NR@CDs has stronger reactive oxygen species (ROS) generation ability. NR@CDs can photodynamically destroy both gram-positive and gram-negative bacteria efficiently, and the minimum inhibitory concentration (MIC) is 45 μg mL−1. NR@CDs spray is an eco-friendly sterilizing agent, with favorable biocompatibility and water-washability properties. Just 1 min of irradiation, NR@CDs spray can quickly and accurately kill the bacteria on the surface of the mouthguards (MGs). As the NR@CDs aqueous solution sprays on cherries, it can effectively prolong the quality guarantee period of perishable foods. The present work provides an innovative strategy to solve the global bacterial contamination and antibiotic resistance problems.

Effect of Pre- and Post-Emergence Herbicides on Weed Control and Yield in Sunflower (Helianthus annuus L.)

Weeds are a major cause of yield and quality loss in sunflower (Helianthus annuus L.) crops. Therefore, weed control is important in sunflower production. In this context, the study was conducted in 2023 to determine the effectiveness of pre-emergence and post-emergence herbicides with different modes of action on weed population, dry weight of weeds and sunflower yield and yield components in sunflower. Four herbicides with different modes of action, three pre-emergence (aclonifen (A), pendimethalin (P), linuron (L) and one post-emergence (quizalofop-p-ethyl) (Q) and combinations of these herbicides were used in the study. To determine the effects of herbicides on weed populations and species, four different assessments were conducted at regular intervals. As a result of the study, a total of 10 weed species belonging to 5 families were detected in the trial area. The weed species with the highest density were Sorghum halepense (L.) Pers., Xanthium strumarium L., Convolvulus arvensis L. and Chenopodium album L. The study found that the effects of herbicides on weed populations and species varied. In the study, the highest rates of weed control were achieved in plots where both pre-emergence and post-emergence herbicides were used together. The highest weed control rate was observed in plots P+Q (96.66%). The highest effect on weed dry weight was obtained in plot L+Q with a rate of 89.63%. The highest weed dry weight was recorded in the weedy control plots. In the study, the highest yield (287.53 kg da-1) was obtained in the weed-free (hoe) control plot. Yield increases of 18% to 45% can be achieved by controlling weeds in sunflowers. As a result, herbicide efficacy on weed population and dry weight of weeds increased when herbicides were used in combination. Some herbicides have been shown to increase yields when used alone. However, it is important to use herbicides in combination to control more weed populations and prevent a potential resistance problem.

Evaluation of anti-vibriocidal, antioxidant properties and cytotoxicity of bio fabricated/green synthesized silver nanoparticles using Euphorbia hitra L. leaf extract

The increasing focus on combating antimicrobial resistance (AMR) in aquaculture sector is driving innovations and better improvements to save billions of dollars globally. Two gram- negative bacteria which cause vibriosis, Vibrio parahaemolytics and Vibrio harveyi, are now resistant to multiple antibiotics. Green technology has evolved to produce novel antimicrobials with reduced potential for AMR and sustainable synthesis. The present study utilized a one-pot biofabrication method to synthesize silver nanoparticles (AgNPs) using Euphorbia hitra leaf aqueous extract (EHLAE) through a bottom-up approach. The qualitative phytochemical examination of EHLAE confirmed the existence of diverse components including steroids, carbohydrates, alkaloids, flavonoids, tannins, terpenoids, saponins, glycosides, and phenols. These compounds have crucial role as reducing and capping AgNPs. The obtained gAgNPs were subjected to evaluate the physico-chemical properties such as Surface Plasmon Resonance (SPR), functional groups, and crystalline structure, were verified by UV-Vis spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), and X-ray diffraction (XRD). The morphology, elemental composition, and size distribution of the AgNPs synthesized using a green method were confirmed using advanced techniques including Field Emission Scanning Electron Microscope (FESEM) with Energy Dispersive X-ray spectroscopy (EDX), High-Resolution Transmission Electron Microscope (HRTEM), and Dynamic Light Scattering (DLS). The silver nanoparticles (AgNPs) shown potent anti-vibriocidal activity against both Vibrio parahaemolyticus and Vibrio harveyi and the Minimum Inhibitory Concentration (MIC) for both bacteria were consistently 31.25 µg mL−1. The in vitro antioxidant tests showed effective results and the found IC50 values are 306 µg mL−1 for DPPH and 6.46 µg mL−1 for FRAP assays. Furthermore, the assessment of in vitro cytotoxicity on Vero cell lines revealed minimal toxicity, as evidenced by an IC50 value of 191.51 µg mL−1. The results reveals that the green synthesized AgNPs using Euphorbia hitra leaf have the potential to be used as effective alternatives for therapeutic purposes in combating the increasing problem of antimicrobial resistance in the aquaculture industry.

Anti-biofilm properties of Portuguese honeys against multi-drug resistant microorganisms: A promising strategy for chronic wounds healing

Honey is considered a promising strategy for chronic wound management, being a possible solution for bacterial resistance problem mostly due to its physical-chemical features. However, these properties might vary significantly depending on the honey floral source. Dark-colored honey, such as chestnut honey, is related to increased antioxidant and bactericidal properties. This study aims to assess biofilms of multidrug-resistant microorganisms in honey samples from the Natural Park of Montesinho, in Portugal, which is considered a region with predominant chestnut floral source. The minimum inhibition concentration (MIC) of honey was tested for Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Candida albicans. The biofilm removal as well as the metabolic inactivation of the biofilms were evaluated using three honey concentrations: 1xMIC, 5xMIC, and 10xMIC. The biofilm viability was analyzed with fluorescent microscopy. Honey samples were characterized according to the pollen profile, phenolic composition, H2O2 levels, tyrosinase inhibition, and pH. The antioxidant capacity was determined through FRAP and ABTS assays. Most of the honey samples exhibited a MIC of 6.75%. Biofilm removal efficacy differs among samples. Regression analysis evidenced a positive correlation between the biofilm removal and concentrations of H2O2, vanillic acid, pinocembrin, Cytisus striatus and Corrigiola telephiifolia, and pH. The honey concentration of 10xMIC was the most effective to inhibit the biofilm metabolism and viability. The concentrations of C. sativa, H2O2, and the anti-tyrosinase and FRAP activities were also positively correlated. The honey samples had a dominant presence of Castanea sativa pollen and were effective against biofilms formed by multidrug-resistant microorganisms.

Synthesis, Characterization, and Biological Evaluation of Chitosan Nanoparticles Cross-Linked with Phytic Acid and Loaded with Colistin against Extensively Drug-Resistant Bacteria.

The natural evolution of microorganisms, as well as the inappropriate use of medicines, have accelerated the problem of drug resistance to many of the antibiotics employed today. Colistin, a lipopeptide antibiotic used as a last resort against multi-resistant strains, has also begun to present these challenges. Therefore, this study was focused on establishing whether colistin associated with chitosan nanoparticles could improve its antibiotic activity on an extremely resistant clinical isolate of Pseudomonas aeruginosa, which is a clinically relevant Gram-negative bacterium. For this aim, nanoparticulate systems based on phytic acid cross-linked chitosan and loaded with colistin were prepared by the ionic gelation method. The characterization included particle size, polydispersity index-PDI, and zeta potential measurements, as well as thermal (DSC) and spectrophotometric (FTIR) analysis. Encapsulation efficiency was assessed by the bicinchoninic acid (BCA) method, while the antimicrobial evaluation was made following the CLSI guidelines. The results showed that colistin-loaded nanoparticles were monodispersed (PDI = 0.196) with a particle size of around 266 nm and a positive zeta potential (+33.5 mV), and were able to associate with around 65.8% of colistin and decrease the minimum inhibitory concentration from 16 μg/mL to 4 μg/mL. These results suggest that the association of antibiotics with nanostructured systems could be an interesting alternative to recover the antimicrobial activity on resistant strains.

The Role of Molecular Dynamics Simulations in Elucidating Interactions between Antimicrobial Peptides and Model Biological Membranes

In addressing the global problem of antimicrobial resistance, an emerging class of molecules called antimicrobial peptides (AMPs) are being widely studied. Their interactions with cell membranes are instrumental in their killing action, usually by forming pores or translocating to act on an internal target. Molecular dynamics (MD) simulations have played an essential role in understanding the atomistic mechanisms of such interactions. This review will highlight key findings from various MD studies, such as the formation of nanoaggregates and different types of pores. We will also discuss the role of selecting the membrane model composition, the level of detail in the simulation, and the choice of force field. It is evident in this review that our understanding of the interactions of AMPs and membranes has grown over the recent years through the help of MD simulations. Still, remaining concerns in MD studies of such systems must be addressed to gain more information.

Comparative analysis of the effectiveness of antibiotic therapy and combined administration of antibiotics, lactobacilli, and proanthocyanidins for asymptomatic bacteriuria in young pregnant women: A randomized prospective study

Background. Asymptomatic bacteriuria in pregnant women is not accompanied by visible symptoms; however, it involves the risk of serious complications, including gestational pyelonephritis and/or preterm labor, thereby threatening the health of both mother and child. This condition raises particular concern in light of the growing global problem of antibiotic resistance causing traditional therapies to be less effective or futile. Therefore, a study into alternative medicine approaches to asymptomatic bacteriuria in pregnant women appears highly relevant in terms of developing new solutions for managing this condition while minimizing maternal and child health risks and preventing the spread of antibiotic resistance.Objectives. To conduct a comparative analysis of the effectiveness of antibiotic therapy and combined administration of antibiotics, lactobacilli, and proanthocyanidins for asymptomatic bacteriuria in young pregnant women.Methods. 50 pregnant women aged 15 to 17 and diagnosed with asymptomatic bacteriuria participated in a randomized prospective study. Patients were randomly divided into two groups depending on the treatment. Group 1 received standard antibiotic therapy; group 2 received a combination of antibiotics with lactobacilli and proanthocyanidins. Treatment was carried out in the Republican Clinical Perinatal Center, the Republic of Bashkortostan. Patients were enrolled in the study from February 2021 to January 2022. The observation period included several stages: 10 days after treatment (first control), 30 days after treatment (second control), and 2 months after delivery (final control). The condition of the urinary tract was assessed depending on bacterial concentration, with the diagnosis of asymptomatic bacteriuria being made in case of a 105 CFE/mL (colony forming units of bacteria per milliliter of urine). The endpoint of the study was considered to be the cure of pregnant women from asymptomatic bacteriuria, which was determined by the absence of bacteria in the urine 10 days after the therapy, as well as a recurrence-free period for two months after delivery. Statistical data processing was carried out using Statistica 10.0 (StatSoft, USA) for Windows and Microsoft Excel (Microsoft, USA). A statistical level with p ≤ 0.05 was considered significant.Results. Treatment outcomes showed a significant reduction in bacteriuria and recurrent infection, especially in the group receiving the combined therapy. No bacteriuria was reported in 36 % of patients in group 1 and 76 % in group 2 (Yates’ chi-squared test, p = 0.011). The incidence of preterm labor appeared lower in the combined therapy group (4 % for group 2 and 12 % for group 1). Complications were recorded in 11 young pregnant women of group 1 (44 %) and in 3 women of group 2 (12 %). Statistical analysis indicated significant differences between the groups in terms of complication rate after treatment (Fisher’s exact test, p = 0.015).Conclusion. Combined therapy including antibiotics, lactobacilli, and proanthocyanidins demonstrates high effectiveness as an alternative to conventional treatments of asymptomatic bacteriuria in pregnant women. Due to this approach, bacteriuria as well as recurrence rate decreases, thereby contributing to a more stable health status.

Unveiling the potential: exploring the efficacy of complex III inhibitors in fungal disease control.

Phytopathogenic fungi are a key challenge to maximizing crop yield and quality for a growing global population. In this review, we give an overview of representative compounds that inhibit complex III, also known as bc1 complex, covering quinone inside inhibitors, quinone outside inhibitors, and quinone inside and outside inhibitors via the stigmatellin binding mode. Novel solutions to the escalating problem of resistance are still required, therefore compounds with alternative scaffolds, alternative docking modes, different mechanisms of action and improved efficacy against complex III necessitate ongoing research. © 2024 Society of Chemical Industry.

Excellent antibacterial and anti-inflammatory efficacy of amoxicillin by AgNPs and their conjugates synthesized using Micromeria biflora crude flavonoid extracts

Antibacterial resistance is considered to be one of the major causes for mortality in coming years. In recent years green nanotechnology played a key role in addressing this problem. Biocompatible metal nanoparticles have gained popularity owing to their excellent therapeutic effects and minimal side effects. MethodWe report the synthesis of AgNPs and their amoxicillin conjugates (Ag-amoxi) using Micromeria biflora crude flavonoid extracts. The physicochemical properties of the synthesized NPs and Ag-amoxi conjugates were systematically evaluated using scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and X-ray diffraction (XRD) analysis, Fourier transform infrared (FTIR), and UV–visible (UV–Vis) spectroscopic techniques. ResultsThe average sizes of AgNPs and Ag-amoxi conjugates were 45 and 62 nm, respectively. We have also explored the antibacterial, antioxidant, anti-inflammatory, and analgesic properties of the AgNPs and Ag-amoxi conjugates through in vivo and in vitro analysis. The Ag-amoxi conjugates showed better antibacterial potential against Streptococcus Pneumoniae (S.P), Staphylococcus aureus (S.A), Pseudomonas aeruginosa (P.A), and Methicillin resistance Staphylococcus aureus (MRSA) strain both the drug and AgNPs. Similarly, in vivo anti-inflammatory studies revealed that both Ag-amoxi (68 %) and AgNPs (64 %) had strong anti-inflammatory effects, with (***p < 0.001) significance at a dose of 10 mg kg−1 body weight as compared to standard, amoxicillin (45 %), and flavonoids extract (48 %) at a dose of 100 mg kg−1. The findings of the antinociceptive activities (writhing and hot plate tests) demonstrated that the Ag-amoxi conjugates produced fewer writhing (15 in 20 s) and a shorter latency time of 22 s as compared to vehicle-treated (tramadol) animals, amoxicillin, and P.E at much lower doses. In vitro antioxidant studies revealed that the Ag-amoxi conjugate has the potential to be used as an antioxidant with an IC50 value of 43.58, compared with AgNPs (46.34), amoxicillin (58.17), compared to the standard of ascorbic acid (34.14). ConclusionThese results reveals that these biologically inspired AgNPs and Ag-amoxi conjugate could be used to improve antibiotic efficiency and could play a critical role in addressing the multidrug resistance problem in coming years.

Antibiotic utilization at an orthopedic inpatient department in a large governmental hospital in the north of the West Bank, Palestine; a retrospective observational study

BackgroundStudies evaluating the patterns of antibiotic consumption are becoming increasingly necessary as a result of the increased use of antibiotics and development of antibiotic resistance globally. This study aimed to evaluate the use of antibiotics in in terms of both quantity and quality at the largest surgical hospital in the north of the West Bank, Palestine.MethodsAn observational retrospective study with a total population sampling method was conducted to collect data from the inpatients of the orthopedic departments of a large governmental hospital in the northern West Bank, Palestine. The data were collected from patients’ files and evaluated using the anatomical therapeutic chemical and defined daily dose (ATC/DDD) methodology, and the drug utilization 90% (DU90%) index. The ATC/DDD methodology, designed by the World Health Organization (WHO), as a well-trusted and standardized tool that allows measuring and comparing antibiotic utilization across different contexts. Antibiotic prescriptions were classified using the World Health Organization Access, Watch and Reserve classification (WHO AWaRe).ResultsOf the 896 patients who were admitted to the hospital in the year 2020 and included in the study, 61.9% were males, and 38.1% were females. The percentage of patients who received antibiotics was 97.0%, and the overall antibiotic usage was 107.91 DDD/100 bed days. The most commonly prescribed antibiotic was cefazolin (50.30 DDD/100 bed days), followed by gentamicin (24.15 DDD/100 bed days) and ceftriaxone (17.35 DDD/100 bed days). The DU90% segment comprised four different agents. Classification of antibiotics according to the WHO AWaRe policy revealed that 75.9% of antibiotics were prescribed from the access list.ConclusionThis study comes as part of the efforts exerted to combat the growing problem of antibiotic resistance in Palestine. Our results showed that the consumption of antibacterial agents in the orthopedic unit at a large governmental hospital in Palestine was relatively high. The results of this study provide valuable insights for the decision-makers to create policies aimed at regulating antibiotic prescriptions. This study also aims to provide a look into the antibiotic prescription patterns, offering a clearer understanding of the current situation of antibiotic consumption in Palestine. It also emphasizes the need for antibiotic stewardship and surveillance programs.

Versatile Fabrication of Biocompatible Antimicrobial Materials Enabled by Cationic Peptide Bundles.

Antimicrobial peptides (AMPs) are expected to be an alternative promising solution to the global public health problem of antibiotic resistance due to their unique antimicrobial mechanism. However, extensive efforts are still needed to improve the shortcomings of traditional AMPs, such as rapid proteolysis, hemolysis, slow response, toxicity, etc., by exploring AMP-based new antimicrobial strategies. Here, we develop cationic peptide bundles into novel antimicrobial architectures that can rapidly kill multiple types of bacteria including drug-resistant bacteria. Remarkably, cationic peptide bundles can be used as polymerization units to cross-link with other polymers through simple two-component polymerization to produce diverse antimicrobial materials. For the proof of concept, three materials were fabricated and investigated, including an antimicrobial hydrogel that can significantly accelerate the healing of infected wounds, a multifunctional antimicrobial bioadhesive that shows promise in antimicrobial coatings for medical devices, and a photo-cross-linked antimicrobial gelatin hydrogel with broad application potential. The integration of antimicrobial units into the materials' backbone endows their biocompatibility. Cationic peptide bundles not only represent a new antimicrobial strategy but also provide a versatile and promising processing method to create diversified, multifunctional, and biocompatible antimicrobial materials.

Design and Experiment of Planting Mechanism of Automatic Transplanter for Densely Planted Vegetables

The planting mechanism of existing transplanters cannot meet the agronomic requirements of planting densely planted vegetables with multiple rows, small plant spacing, and small row spacing. In order to solve this current problem, an eight-row duckbill planting mechanism driven by a motor and a cylinder was designed. According to the agronomic guidance and mechanism design requirements for transplanting densely planted vegetable seedlings, this paper analyzes the working principle of the planting mechanism, establishes its kinematic theoretical model, and determines the structural parameters of the driving device and opening and closing device in the planting mechanism. Aimed at the problem of large planting resistance when eight-row planting end effectors of the planting mechanism are planting at the same time, based on the existing research, three duckbill planting end effectors with double incisions, four incisions, and conical structures were selected, and the planting process was simulated using an EDEM 2022-RecurDyn 2024 coupling simulation. The single-factor analysis method and the interactive factor Box–Behnken response surface analysis method were used. It is concluded that the duckbill end effector with double incisions has the smallest planting resistance, and the rationality of the mechanism design is preliminarily verified. A planting resistance measurement platform was built based on the STM32 platform and HX711 module, and a planting resistance test of the duckbill planting end effector was carried out to verify the correctness of the planting mechanism simulation results. The planting mechanism performance test was carried out, and the test results showed that the planting qualification rate of the prototype reached 96.62%, the planting spacing variation coefficient was only 3.55%, and the planting efficiency reached about 7135 plants/h, which met the agronomic requirements of small plant spacing and small row spacing for densely planted vegetables and verified the feasibility and practicality of the planting mechanism.

High Therapeutic Index α-Helical AMPs and Their Therapeutic Potential on Bacterial Lung and Skin Wound Infections.

Antimicrobial peptides (AMPs) possess strong antibacterial activity and low drug resistance, making them ideal candidates for bactericidal drugs for addressing the issue of traditional antibiotic resistance. In this study, a template (G(XXKK)nI, G = Gly; X = Leu, Ile, Phe, or Trp; n = 2, 3, or 4; K = Lys; I = Ile.) was employed for the devised of a variety of novel α-helical AMPs with a high therapeutic index. The AMP with the highest therapeutic index, WK2, was ultimately chosen following a thorough screening process. It demonstrates broad-spectrum and potent activity against both standard and multidrug-resistant bacteria, while also showing low hemolysis and rapid and efficient time-kill kinetics. Additionally, WK2 exhibits excellent efficacy in treating mouse models of Klebsiella pneumonia-induced lung infections and methicillin-resistant Staphylococcus aureus (MRSA)-induced skin wound infections while demonstrating good safety profiles in vivo. In conclusion, the template-based design methodology for novel AMPs with high therapeutic indices offers new insights into addressing antibiotic resistance problems. WK2 represents a promising antimicrobial agent.

Potential role of Manilkara Zapota L in treating bacterial infection.

The increasing problem of antibiotic resistance in bacteria leads to an urgent need for new antimicrobial agents. Alternative treatments for bacterial infections need to be explored to tackle this issue. Plant-based substances are emerging as promising options. Manilkara zapota L. contains compounds with antibiotic activities, and anti-inflammatory, antitumor, antipyretic, and antioxidant properties. It has medicinal properties and contains bioactive compounds, like tannins, flavonoids, and triterpenoids. This review aimed to comprehensively evaluate the existing literature on the potential medicinal and therapeutic benefits of M. zapota in bacterial infections by utilizing data from in vivo and in vitro studies. M. zapota has the potential to be a nutritional source of antimicrobial food. Numerous preclinical studies have demonstrated the antibacterial activities of M. zapota and its components. The antibacterial mechanisms of this fruit could interact with bacterial cell structures such as cell walls or membranes.

Ru-terpyridine complexes containing clotrimazole as potent photoactivatable selective antifungal agents

The overuse of antimicrobial agents in medical and veterinary applications has led to the development of antimicrobial resistance in some microorganisms and this is now one of the major concerns in modern society. In this context, the use of transition metal complexes with photoactivatable properties, which can act as drug delivery systems triggered by light, could become a potent strategy to overcome the problem of resistance. In this work several Ru complexes with terpyridine ligands and the clotrimazole fragment, which is a potent antimycotic drug, were synthesized. The main goal was to explore the potential photoactivated activity of the complexes as antifungal agents and evaluate the effect of introducing different substituents on the terpyridine ligand. The complexes were capable of delivering the clotrimazole unit upon irradiation with visible light in a short period of time. The influence of the substituents on the photodissociation rate was explained by means of TD-DFT calculations. The complexes were tested against three different yeasts, which were selected based on their prevalence in fungal infections. The complex in which a carboxybenzene unit was attached to the terpyridine ligand showed the best activity against the three species under light, with minimal inhibitory concentration values of 0.88 μM and a phototoxicity index of 50 achieved. The activity of this complex was markedly higher than that of free clotrimazole, especially upon irradiation with visible light (141 times higher). The complexes were more active on yeast species than on cancer cell lines.