Antimicrobial Research Articles

Recent advances in bioactive wound dressings.

Traditional wound dressings, despite their widespread use, face limitations, such as poor infection control and insufficient healing promotion. To address these challenges, bioactive materials have emerged as a promising solution in wound care. This comprehensive review explores the latest developments in wound healing technologies, starting with an overview of the importance of effective wound management, emphasising the need for advanced bioactive wound dressings. The review further explores various bioactive materials, defining their characteristics. It covers a wide range of natural and synthetic biopolymers used to develop bioactive wound dressings. Next, the paper discusses the incorporation of bioactive agents into wound dressings, including antimicrobial and anti-inflammatory agents, alongside regenerative components like growth factors, platelet-rich plasma, platelet-rich fibrin and stem cells. The review also covers fabrication techniques for bioactive wound dressings, highlighting techniques like electrospinning, which facilitated the production of nanofibre-based dressings with controlled porosity, the sol-gel method for developing bioactive glass-based dressings, and 3D bioprinting for customised, patient-specific dressings. The review concludes by addressing the challenges and future perspectives in bioactive wound dressing development. It includes regulatory considerations, clinical efficacy, patient care protocol integration and wound healing progress monitoring. Furthermore, the review considers emerging trends such as smart materials, sensors and personalised medicine approaches, offering insights into the future direction of bioactive wound dressing research.

Anticancer, antimicrobial, insecticidal and molecular docking of sarcotrocheliol and cholesterol from the marine soft coral Sarcophyton Trocheliophorum.

The anticancer, antimicrobial, and insecticidal activities of sarcotrocheliol (1) and cholesterol (2) obtained from the soft coral Sarcophyton trocheliophorum (S. trocheliophorum) were intensively studied. According to this study, both compounds 1 and 2 showed potential cytotoxicity towards the human colorectal carcinomaHCT-116 (IC50 10.4, 11.8µg/mL) and human liver carcinoma HepG2 cell lines (IC50 8.8, 12.0µg/mL), respectively. Compounds 1 and 2 were evaluated as potential inhibitors of caspase-3, a member of the cysteine protease family, which is considered a key enzyme in inducing cell apoptosis. Results showed that compounds 1 and 2 have induced apoptosis via up-regulation of caspase-3. Sarcotrocheliol (1) displayed antimicrobial activity against P. aeruginosa (15mm), B. subtilis (15mm), M. luteus (14mm) and C. albicans (15mm), with a MIC of 1.5µg/mL against the reported test microorganisms. On the other hand, cholesterol (2) showed less activity towards P. aeruginosa (10mm), B. subtilis (14mm), S. aureus (12mm) and C. albicans (10mm) with MICs of 3.0, 1.5, 1.5 and 3.0µg/mL against the tested microorganisms, respectively. Larvicidal activity revealed that compounds 1 and 2 induced remarkable toxicity against the third instar larvae of the mosquito, Culex pipiens even at concentration of 2 ppm. Adulticidal activity data showed that tested compounds are distinctly potent toxicants against the housefly, Musca domestica adult females. Overall, compound 2induced much more insecticidal activity than 1, and M. domestica adult females were more sensitive to tested compounds than C. pipiens larvae. Computationally, Density Functional Theory (DFT) analyses revealed that compound 2 had a higher dipole moment and lower band gap energy when compared to compound 1. So, compounds 2 is chemically more reactive and less stable than compound 1. According to the molecular docking study against PDB IDs: 3KJF, 5UHF and 1ACJ, compounds 1 and 2 demonstrated their activity mode as anticancer, antimicrobial, and insecticidal agents. The compounds exerted many interactions and showed high binding to the proteins, recognizing their potential as drug candidates with broad bioactivities.

A systematic overview of strategies for photosensitizer and light delivery in antibacterial photodynamic therapy for lung infections.

Antimicrobial photodynamic therapy (aPDT) emerges as a viable treatment strategy for infections resistant to conventional antibiotics. A complex interplay of factors, including intracellular photosensitizer (PS) accumulation, photochemical reaction type, and oxygen levels, determines the efficacy of aPDT. Recent progress includes the development of modified PSs with enhanced lipophilicity and target-specific strategies to improve bacterial cell wall penetration and targeting. Nanotechnology-based approaches, such as using nanomaterials for targeted PS delivery, have shown promise in enhancing aPDT efficacy. Advancements in light delivery methods for aPDT, such as transillumination of large lesions and local light delivery using fiber optic techniques, are also being explored to optimize treatment efficacy in clinical settings. The limited number of animal models and clinical trials specifically designed to assess the efficacy of aPDT for lung infections highlights the need for further research in this critical area. The potential prospects of aPDT for lung tissue infections originating from antibiotic-resistant bacterial infections are also discussed in this review.

A longitudinal point prevalence survey of antimicrobial use and resistance in tertiary care hospitals in Kerman: results from the national Iranian multicenter point prevalence survey of antimicrobials in 2021.

The Global Point Prevalence Survey (PPS) of antimicrobial consumption and resistance has been widely undertaken to combat the global threat of antimicrobial resistance (AMR). This study was conducted in alignment with the Global-PPS in three tertiary care hospitals in Kerman, Iran, to evaluate antimicrobial consumption patterns. The study was conducted from January 2020 to January 2021 in Afzalipour, Shafa, and Shahid Bahonar Hospitals. Data were collected using the standardized Global-PPS method at three different points throughout the year to minimize bias. Information on antimicrobial prescriptions, primary diagnosis, prophylaxis, therapy indications, and treatment type were documented. Antimicrobial prevalence was calculated using the total number of admitted patients as the denominator and those on antimicrobial regimens as the numerator. The point prevalence of antimicrobial consumption in adult wards was 65.6% in Afzalipour Hospital, 42.3% in Shafa Hospital, and 78.7% in Bahonar Hospital. Non-penicillin beta-lactams, macrolides, lincosamides, and streptogramins were the most frequently prescribed antibiotic classes. Approximately 80% of prescriptions had explicit reasons documented, and targeted antibiotic therapy rates varied between 7.7% and 44.8% across hospitals. Antimicrobial consumption in Kerman's tertiary care hospitals exceeded national and global levels, indicating an urgent need for interventions to promote rational antibiotic use. Infection control committees must implement rigorous monitoring measures to reduce antimicrobial resistance. Ongoing surveillance and targeted interventions are essential to curb the rising rates of antimicrobial resistance in the region.

Phytogenic Synthesis of Cuprous and Cupric Oxide Nanoparticles Using Black jack Leaf Extract: Antibacterial Effects and Their Computational Docking Insights

Background: Green synthesized nanoparticles (NPs) have gained increasing popularity in recent times due to their broad spectrum of antimicrobial properties. This study aimed to develop a phytofabrication approach for producing cuprous (Cu2O) and cupric oxide (CuO) NPs using a simple, non-hazardous process and to examine their antimicrobial properties. Methods: The synthesis employed Bidens pilosa plant extract as a natural reducing and stabilizing agent, alongside copper chloride dihydrate as the precursor. The biosynthesized NPs were characterized through various techniques, including X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier-transform infrared (FT-IR) spectroscopy, ultraviolet–visible (UV-Vis) spectroscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). Results: XRD analysis confirmed that the synthesized CuO and Cu2O NPs exhibited a high degree of crystallinity, with crystal structures corresponding to monoclinic and face-centered cubic systems. SEM images revealed that the NPs displayed distinct spherical and sponge-like morphologies. EDS analysis further validated the purity of the synthesized CuO NPs. The antimicrobial activity of the CuO and Cu2O NPs was tested against various pathogenic bacterial strains, including Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Bacillus cereus, with the minimum inhibitory concentration (MIC) used to gauge their effectiveness. Conclusions: The results showed that the phytosynthesized NPs had promising antibacterial properties, particularly the Cu2O NPs, which, with a larger crystal size of 68.19 nm, demonstrated significant inhibitory effects across all tested bacterial species. These findings suggest the potential of CuO and Cu2O NPs as effective antimicrobial agents produced via green synthesis.

Formulation and Evaluation of the Antimicrobial Potential and Embryotoxicity of Betanin-Zinc Nanoparticles

Introduction: This study explores the green synthesis of betanin-based ZnO nanoparticles, with emphasis on their characterization, antimicrobial potential, and toxicity evaluation. Materials and methods: Zinc oxide nanoparticles (ZnO NPs) were produced using betanin isolated from Beta vulgaris, zinc hexahydrate, and 0.5M NaOH. To verify their structural and morphological characteristics, the produced betanin zinc oxide nanoparticles (BT-ZnO NPs) were examined using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and X-Ray Diffraction (XRD). Staphylococcus aureus, Streptococcus mutans, Enterococcus faecalis, and Candida albicans were among the bacterial strains against which the antibacterial activity of these green-synthesised BT-ZnO NPs was assessed. Concurrently, zebrafish (Danio rerio) embryos were subjected to different amounts (10, 50, and 100 µg/mL) in order to perform embryotoxicity experiments. Results: SEM analysis showed that BT-ZnO NPs are irregularly shaped with a tendency to aggregate, which may enhance surface area. FTIR confirmed functional groups like phenols and amines, aiding nanoparticle stability. XRD indicated a composition of 52.5% crystalline and 47.5% amorphous content, supporting structural stability and bioactivity. Anti-microbial potential of BT-ZnO NPs shows notable inhibition at higher concentrations. In contrast, Candida albicans exhibited resistance to the nanoparticles. Embryotoxicity results showed that the ZnO NPs caused decreased survival rates, hatching delays, and morphological abnormalities in the zebrafish embryos, such as tail malformations and yolk sac oedema in the 100 µg/mL treatment group. Conclusion: While this study demonstrates the efficacy of BT-ZnO NPs as strong antimicrobial agents, it also emphasizes the need for caution regarding their environmental and health impacts, particularly at higher concentrations.

The Underrepresented Quinolinone Alkaloids in Genera Penicillium and Aspergillus: Structure, Biology, and Biosynthetic Machinery.

Quinolone alkaloids are N-heterocycles with extensive structural diversity, mainly derived from in fungi from anthranilic acid and amino acids as precursors with a wide range of biological activities as antifungal, antimicrobial, anti-inflammatory, and insecticidal activities. The quinolone basic skeleton comprised of either 2-quinolones or 4-quinolones generated more than one hundred compounds. Several reviews discussed quinolones; particularly, the fluoroquinolones, yet few studies tackled natural quinolones. Many of these quinolones were not assayed for their antimicrobial potential despite their unique stereospecificity, which can supersede synthetic quinolones if their discovery is coupled with OMICS techniques, biochemical and molecular strategies as heterologous expression to maximize their yield. Herein, we conducted a comprehensive review of the quinolone's family in Aspergillus and Penicillium species, the exclusive producers of quinolones whether they are soil, endophytic or marine derived highlighting their isolation, chemical structures, pharmacological effects, structure activity relationships if any, and biosynthetic machinery. We believe that our initiative will pave the way for further development of natural quinolones as future antimicrobial agents.

Synthesis and evaluation of vanillin Schiff bases as potential antimicrobial agents against ESBL-producing bacteria: towards novel interventions in antimicrobial stewardship.

The escalating challenge of antimicrobial resistance necessitates the development of novel antibacterial agents. In this study, a series of five vanillin Schiff bases (SB-1 to SB-5) were synthesized from vanillin and various aromatic amines. The chemical structures of these compounds were characterized using Thin Layer Chromatography (TLC), Fourier Transform Infrared Spectroscopy (FT-IR), proton nuclear magnetic resonance ( -NMR), carbon-13 NMR ( -NMR), and mass spectrometry techniques. Antibacterial efficacy was evaluated against strains of bacteria producing extended-spectrum beta-lactamases (ESBL), including Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae using the disc diffusion method. Cytotoxic effects were assessed through haemocompatibility and brine shrimp lethality assays. The Schiff bases demonstrated notable antibacterial activities, with SB-1, SB-2, SB-4, and SB-5 exhibiting zones of inhibition up to 16.0, 16.5, 16.6, and 15.5 mm against ESBL E. coli, respectively. SB-3 showed a maximum inhibition zone of 15.0 mm against ESBL K. pneumoniae. In cytotoxicity assays, the compounds exhibited IC values against red blood cells (RBCs) greater than 200 μg/mL and ranging from 45.7 to 50.5 μg/mL for the brine shrimp assay. While demonstrating potent antibacterial properties, the toxicity towards human RBCs suggests that further toxicity evaluations and structural modifications are essential for developing safer therapeutic agents based on vanillin Schiff bases.

Helicobacter pylori Efflux Pumps: A Double-Edged Sword in Antibiotic Resistance and Biofilm Formation

Helicobacter pylori is a major pathogen associated with various gastric diseases. Despite decades of research, the treatment of H. pylori remains challenging. One of the primary mechanisms contributing to failures of therapies targeting this bacterium is genetic mutations in drug target sites, although the growing body of scientific data highlights that efflux pumps may also take part in this process. Efflux pumps are proteinaceous transporters actively expelling antimicrobial agents from the interior of the targeted cells and reducing the intracellular concentration of these compounds. Considering that efflux pumps contribute to both antimicrobial resistance and biofilm formation, an in-depth understanding of their properties may constitute a cornerstone in the development of novel therapeutics against H. pylori. In line with this, the aim of the current review is to describe the multitude of efflux pumps produced by H. pylori and present the data describing the involvement of these proteins in tolerance and/or resistance to various classes of antimicrobial substances.

Risk Factors for Invasive Surgical Site Infections Among Adult Single Liver Transplant Recipients at Duke University Hospital in the Period 2015–2020

Background. Invasive primary surgical site infections (IP-SSI) are a severe complication of liver transplant surgery. Identification of risk factors for IP-SSI is critical to IP-SSI prevention. Methods. All adult single liver transplants performed at Duke University Hospital in the period 2015–2020 were reviewed for IP-SSI occurring within 90 d of transplant. Risks for IP-SSI were identified using least absolute shrinkage and selection operator variable selection procedure. A 2-sided P value of <0.05 was considered statistically significant. Results. IP-SSI were identified in 34/470 (7.2%) adult single liver transplants. Repeat transplantation, spilt liver, Roux-en-Y biliary anastomosis, anastomotic leak, and post-transplant renal replacement therapy were positively associated with IP-SSI. IP-SSI were associated with increased length of index transplant hospitalization (24.5 versus 10.0 d, P < 0.01) and 1-y all-cause mortality (14.7% versus 4.1%, P = 0.02). Gram positive bacteria were the main pathogens (51.7%), followed by Gram negative bacteria (24.1%) and Candida (24.1%). Multidrug resistance bacteria increased over time (27.3% in 2015 versus 66.7% in 2020, P = 0.17). Conclusions. In the setting of routine antimicrobial prophylaxis and an overall low rate of IP-SSI, surgical factors were the main determinants of IP-SSI among adult liver transplant recipients. IP-SSI had a negative impact on the length of index transplant hospitalization and 1-y mortality. While the surgical factors associated with an increased risk of IP-SSI are not easily modifiable, their impact may be best contained by close clinical monitoring and tailored antimicrobial therapy.

Gene profile of virulence, antimicrobial resistance and action of enterocins in Campylobacter species isolated from broiler carcasses.

Campylobacteriosis is among the most reported zoonoses in the world, caused by species of Campylobacter, this disease is characterized by gastroenteritis in humans. The main species involved is Campylobacter jejuni, followed by Campylobacter coli. Contaminated chicken meat is often identified as an important source of infection related to human cases and Brazil is the largest exporter of chicken meat in the world, which makes the characterization of brazilian isolates crucial for the establishment of control measures. The objective was to evaluate the contamination of chilled and frozen carcasses sold in the Northeast of Brazil, by Campylobacter species, identify virulence genes, evaluate bacterial resistance to antibiotics and verify the antimicrobial action of the Crude Extract Containing Enterocins (CECE) produced by a probiotic strain of Enterococcus faecium. In this study, 12 chilled carcasses and 12 frozen carcasses were collected, sold retail in supermarkets. The following regions of the carcass were sampled: breast skin, wing skin, belly skin, neck skin, gizzard and liver. Samples of chicken carcasses were analyzed following ISO 10272-2 guidelines for the isolation of Campylobacter spp. The isolates were tested by PCR to identify genus, species C. jejuni, C. coli and C. lari and genes cdtA, cdtB, cdtC, sodB, dnaJ, cmeA, cmeB, cmeC. The assessment of susceptibility to antibiotics was carried out using the standard disk diffusion method and the antimicrobial activity of CECE was determined using the Minimum Inhibitory Concentration (MIC), the methodologies followed the recommendations and cutoff points according to EUCAST and CLSI. A total of 376 isolates of Campylobacter spp. were obtained, among these, 26 (7.0%) were positive for C. jejuni and no isolates were detected for C. coli and C. lari. The highest frequency of C. jejuni was obtained in chilled carcasses with 23 isolates (88.5%, p < 0.0001), in frozen carcasses three isolates were obtained (11.5%). The most frequency site of C. jejuni was the chest skin (7/27.0%), followed by skin of the wing (6/23.0%), skin of the cloaca (5/19.0%), gizzard (4/15.0%), skin of the neck (2/8.0%) and liver (2/8.0%), no significant differences were found between the sites sampled. The gene frequency was determined in: cdtA (3/11.5%), cdtB (3/11.5%), cdtC (5/19.0%), sodB (9/34.5%), dnaJ (3/11.5%), cmeA (4/15.0%), cmeB (4/15.0%) and cmeC (4/15.0%). The three efflux pump genes were amplified in four isolates (15.3%) and all tested genes were amplified in three isolates (11.5%). All C. jejuni isolates (26/100.0%) were found to be multiresistant to three or more classes of antimicrobials. The index of multiple resistance to antimicrobial drugs (IRMA) ranged from 0.4 to 1.0 among isolates of C. jejuni. The antimicrobial activity of CECE was able to inhibit at least 98.5% of the growth of all C. jejuni isolates. Therefore, chilled chicken carcasses present a greater risk of contamination than frozen carcasses, for this reason it is necessary to adopt practices that avoid cross-contamination during the preparation of chicken meat, in order to prevent campylobacteriosis. Furthermore, the presence of multiresistant and potentially virulent isolates highlights the need for further investigations to better understand the use of enterocins as alternative methods in the control of Campylobacter.

Antibiotic consumption patterns in older adults: a comparative study of people 65 years and older in and outside nursing homes, Belgium, 2016 to 2022.

BackgroundInappropriate antimicrobial consumption (AMC) drives the emergence of antimicrobial resistance. Institutionalised, older populations are associated with antimicrobial treatments of longer duration and broader spectrum than recommended, higher rates of multidrug-resistant infections and poorer outcomes for resistant infections. Yet systematic, national monitoring of AMC in nursing home (NH) residents is lacking.AimTo perform a retrospective analysis of antibiotic consumption in Belgian NHs, we compared analogous populations inside and outside NHs. We aimed to provide a blueprint for establishing surveillance of NH AMC, based on national reimbursement data.MethodsThe National Institute for Health and Disability Insurance supplied reimbursement AMC data for outpatients from 2016 to 2022. Data were classified by the Anatomical Therapeutic Chemical system, expressed as defined daily doses (DDD) and aggregated by prescription month, patient age, sex and residency inside/outside a NH. The number of ensured beneficiaries, aggregated by the same demographic variables, was collected from the Intermutualistic Agency. We compared the DDDs per 1,000 beneficiaries per day, along with secondary metrics for national and international targets for analogous populations inside and outside NHs.ResultsTotal antibiotic consumption decreased in both populations but remained twofold higher in NH residents. Proxy prescription quality metrics were consistently less favourable within NHs and diverged further during the COVID-19 pandemic. Distinct consumption patterns and greater seasonal fluctuations were observed in NH residents.ConclusionGiven the different infection risks and higher antibiotic consumption of NH residents, AMC surveillance and antimicrobial stewardship efforts targeting this fragile population are needed.

Distinction of clinical features and microbiological methods between Chlamydia psittaci and Legionella pneumophila pneumonia confirmed by metagenomic next-generation sequencing

Objectives Detection and diagnosis of Chlamydia psittaci (C. psittaci) pneumonia is often overlooked due to conventional methods limitations and similarity to other atypical community acquired pneumonia (CAP). Using mNGS, we aimed to distinguish psittacosis from legionellosis for early C. psittaci pneumonia diagnosis and better prognosis. Methods Thirty-seven patients diagnosed with atypical CAP were enrolled in this retrospective study, including 14 C. psittaci pneumonia and 23 Legionella pneumophila (L. pneumophila) pneumonia. We collected and compared baseline, lab results, radiology imaging, conventional microbiological methods and more importantly, mNGS results of clinical samples, as well as the treatments and prognosis between psittacosis and legionellosis. Results Patients with C. psittaci and L. pneumophila had similar symptoms and were presented with high levels of inflammatory markers. However, patients with C. psittaci pneumonia were more likely to have exposure to birds or parrots [11 (78.6%) vs. 2 (8.7%), p < 0.001], had higher proportions of fever and chill (p = 0.015 and 0.035), higher levels of hemoglobin and albumin (p = 0.002 and 0.018) compared with those with L. pneumophila. Of 14 C. psittaci patients, only one had positive IgM antibody, with no positive cultures. Early identification of pathogens by mNGS method contributed to timely antibiotics’ adjustment and better outcomes then, yet with similar hospital mortality between two groups [7.1% (1/14) vs. 34.8% (8/23), p = 0.112]. Conclusion Early mNGS detection of atypical pathogens in multiple samples improves on traditional methods, promptly adjust empirical antimicrobial treatment to pathogen-targeted antibiotics, further improve prognosis.

Identification of 2,4-Di-tert-Butylphenol as an Antimicrobial Agent Against Cutibacterium acnes Bacteria from Rwandan Propolis

Background/Objectives: Acne is the most prevalent dermatological condition among humans, affecting approximately 80% of adolescents during puberty. To date, numerous compounds have been used for acne treatment, including erythromycin ointments and antiseptics, with varying degrees of success. The emergence of erythromycin-resistant C. acnes strains has spurred the search for new antimicrobial agents, particularly from natural sources. Methods: Propolis collected in Rwanda was extracted and fractionated by flash chromatography and tested against C. acnes growth by using NCLSI recommendations. Results: In our research, we identified a molecule, 2,4-Di-tert-butylphenol (2,4-DTBP) which inhivbited the C. acnes growth at a concentration of 16 µg/mL. Based on these results, we formulated an ointment (1%) using OFAP18 and petroleum jelly for the potential treatment of acne using a mouse model. Conclusions: In vitro and in vivo evidence suggests that 2,4-DTBP has anti-inflammatory properties and could effectively manage the overgrowth of C. acnes as well as serve as a potent alternative for the formulation of an active propolis ointment for acne treatment.

Isolation and identification of antifungal, antibacterial and nematocide agents from marine bacillus gottheilii MSB1.

Pathogenic fungi employ numerous strategies to colonize plants, infect them, reduce crop yield and quality, and cause significant losses in agricultural production. The increasing use of chemical pesticides has led to various ecological and environmental issues, including the emergence of resistant weeds, soil compaction, and water pollution, all negatively impacting agricultural sustainability. Additionally, the extensive development of synthetic fungicides has adverse effects on animal and human health, prompting the exploration of alternative approaches and green strategies for phytopathogen control. Microorganisms living in sponges represent a promising source of novel bioactive secondary metabolites, potentially useful in developing new nematicidal and antimicrobial agents. This study focuses on extracting bioactive compounds from endosymbiotic bacteria associated with the marine sponge Hyrtios erect sp. (collected from NIOF Station, Hurghada, Red Sea, Egypt) using various organic solvents. Bacillus sp. was isolated and identified through 16S rRNA gene sequencing. The biocidal activity of Bacillus gotheilii MSB1 extracts was screened against plant pathogenic bacteria, fungi, and nematodes. The n-butanol extract showed significant potential as a biological fungicide against Alternaria alternata and Fusarium oxysporum. Both n-hexane and ethyl acetate extracts exhibited negative impacts against the plant pathogenic bacteria Erwinia carotovora and Ralstonia solanacearum, whereas the n-butanol extract had a positive effect. Regarding nematicidal activity, ethyl acetate and n-butanol extracts demonstrated in-vitro activity against the root-knot nematode Meloidogyne incognita, which causes serious vegetable crop diseases, but the n-hexane extract showed no positive effects. The findings suggest that bioactive compounds from endosymbiotic bacteria associated with marine sponges, particularly B. gotheilii MSB1, hold significant potential as alternative biological control agents against plant pathogens. The n-butanol extract, in particular, displayed promising biocidal activities against various plant pathogenic fungi, bacteria, and nematodes. These results support further exploration and development of such bioactive compounds as sustainable, environmentally friendly alternatives to synthetic pesticides and fungicides in agricultural practices.

Green Synthesis of Silver Nanoparticles Using Doxycycline: Evaluation of Antimicrobial Potential and Organ-specific Toxicity

Silver nanoparticles (Ag-NPs) have wide applicability as antimicrobial, biomedical, and anti-cancer drug delivery systems. This study aimed to synthesize Ag-NPs using green methodology to assess their antimicrobial properties and toxicity. Ag-NPs were prepared using doxycycline, an antibiotic serving as a reducing and capping agent. The synthesized Ag-NPs were characterized by ultraviolet-visible spectrophotometry, X-ray diffraction, scanning electron microscopy, and Fourier-transform infrared spectrometry. The antimicrobial efficacy of doxycycline-mediated Ag-NPs was assessed on Candida species in vitro and for toxicity in male albino mice in vivo. The Ag-NPs showed a surface plasmon resonance at 411 nm, indicating a 90 nm average size and spherical shape. Toxicity was tested on mouse organs (liver, kidney, spleen, heart and stomach) using three Ag-NP doses (50, 100, 200 mg/kg) over 14 days. The synthesized Ag-NPs produced large inhibition zones against two well-known fungal species, C. albicans and C. tropicalis, demonstrating their antimicrobial potential. The Ag-NPs showed varying degrees of toxicity in different mouse organs, depending on the administered dose, with more pronounced adverse effects observed at higher concentrations. Periodic administration of Ag-NPs at low-dose volumes holds promise as a safe approach to their use as antimicrobial agents. Low-dose Ag-NPs are minimally toxic and show strong antimicrobial efficacy.

The versatile NDI-based compounds: emerging anticancer and antimicrobial agents

The versatile NDI-based compounds: emerging anticancer and antimicrobial agents

Efficiency of a Long-term Infectious Disease Consultation and Antimicrobial Stewardship Program at a Japanese Cancer Center: An Interrupted Time-Series Analysis

Abstract Background Patients with cancer are particularly susceptible to developing drug-resistant organisms due to the high frequency of infections during cancer treatment and the use of broad-spectrum antimicrobial agents. Therefore, patients with cancer are ideal candidates for an antimicrobial stewardship program (ASP); however, no established ASPs specifically target these patients. In this study, we evaluated the effect of a 46-month ASP intervention and infectious diseases (ID) consultation using a unique antimicrobial quality measure. Methods Our single-center, retrospective, observational study was conducted from April 1, 2018, to January 31, 2024, and evaluated two phases: pre-intervention (antimicrobial notification by the infection control team) and post-intervention (implementation of ASP and establishment of the ID consultation service). Results The days of therapy (DOT) for three intravenous carbapenems significantly decreased, and the DOT of narrow-spectrum antimicrobials significantly increased after the intervention. A significant reduction was observed in the length of hospital stay, with no change in the incidence of hospital-acquired resistant microorganisms. All-cause in-hospital mortality rates and the 30-day mortality rate among patients with bacteremia episodes were numerically reduced, although not significantly, compared to the pre-intervention period. The rate of appropriate use of antimicrobial agents increased significantly during the late post-intervention period (April 1, 2021, to January 31, 2024). Conclusions Our intervention was associated with the promotion of appropriate use of antimicrobial agents and a reduction in the length of hospital stay. These findings can help establish safer cancer treatments and improve patient prognosis.

“Antimicrobial and antioxidant capacity of Dunaliella salina, Tetraselmis chuii and Isochrysis galbana and their potential use in food.” a systematic review

AbstractThe main compounds extracted from the biomass of marine microalgae have antioxidant, antimicrobial, antifungal, anti-inflammatory and antitumor effects, making the possibility of using these properties in the development of foods feasible. Despite the proven biological activity of microalgae, there are still challenges regarding the production and use of microalgal biomass or its derivatives in food industries that are related to high production costs, and there is little research regarding the evaluation of their safety and the search for their application in food development. Therefore, this research aimed to collect information regarding the biological activities of marine microalgae, which allows their use as a natural antimicrobial additive in food matrices and as an ingredient in the development of functional foods with antioxidant capacity. The search interval for the PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines was five years. Different methods for the extraction of antioxidant and antimicrobial compounds from the marine microalgae Dunaliella salina, Tetraselmis chuii and Isochrysis galbana were compared and discussed, and the viability of their use and application in food matrices and in the food industry in general were analyzed. It was concluded that there are research gaps in the use of microalgae biomass as an extract, the identification of bioactive molecules for use in the food industry as antimicrobial agents and for the development of functional foods with antioxidant capacity.

Bispecific Thio-linked Disaccharides as Inhibitors of Pseudomonas aeruginosa Lectins LecA (PA-IL) and LecB (PA-IIL): Dual-Targeting Strategy.

Pseudomonas aeruginosa is a prevalent opportunistic human pathogen, particularly associated with cystic fibrosis. Among its virulence factors are the LecA and LecB lectins. Both lectins play an important role in the adhesion to the host cells and display cytotoxic activity. In this study, we successfully synthesized hardly hydrolysable carbohydrate ligands targeting these pathogenic lectins, including two bispecific glycans. The interactions between LecA/LecB lectins and synthetic glycans were evaluated using hemagglutination (yeast agglutination) inhibition assays, comparing their efficacy with corresponding monosaccharides. Additionally, the binding affinities of bispecific glycans were assessed using isothermal titration calorimetry (ITC). Structural insight into the lectin-ligand interaction was obtained by determining the crystal structures of LecA/LecB lectins in complex with one of the bispecific ligands using X ray crystallography. This comprehensive investigation into the inhibitory potential of synthetic glycosides against P. aeruginosa lectins sheds light on their potential application in antimicrobial therapy.