-
Bioprocess and Biosystems Engineering Jun 2024Bio-inspired zinc oxide nanoparticles are gaining immense interest due to their safety, low cost, biocompatibility, and broad biological properties. In recent years,...
Bio-inspired zinc oxide nanoparticles are gaining immense interest due to their safety, low cost, biocompatibility, and broad biological properties. In recent years, much research has been focused on plant-based nanoparticles, mainly for their eco-friendly, facile, and non-toxic character. Hence, the current study emphasized a bottom-up synthesis of zinc oxide nanoparticles (ZnO NPs) from Psidium guajava aqueous leaf extract and evaluation of its biological properties. The structural characteristic features of biosynthesized ZnO NPs were confirmed using various analytical methods, such as UV-Vis spectroscopy, X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDX), Fourier transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS), Scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HR-TEM). The synthesized ZnO NPs exhibited a hydrodynamic shape with an average particle size of 11.6-80.2 nm. A significant antimicrobial efficiency with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of 40 and 27 µg/ml for Enterococcus faecalis, followed by 30 and 40 µg/ml for Staphylococcus aureus, 20 and 30 µg/ml for Staphylococcus mutans, 30 µg/ml for Candida albicans was observed by ZnO NPs. Additionally, they showed significant breakdown of biofilms of Streptococcus mutans and Candida albicans indicating their future value in drug-resistance research. Furthermore, an excellent dose-dependent activity of antioxidant property was noticed with an IC of 9.89 µg/ml. The antiproliferative potential of the ZnO NPs was indicated by the viability of MDA MB 231 cells, which showed a drastic decrease in response to increased concentrations of biosynthesized ZnO NPs. Thus, the present results open up vistas to explore their pharmaceutical potential for the development of targeted anticancer drugs in the future.
PubMed: 38935113
DOI: 10.1007/s00449-024-03052-x -
Journal of Clinical Microbiology Jun 2024In this study, we investigated the genomic changes in a major methicillin-resistant (MRSA) clone following a significant outbreak at a hospital. Whole-genome sequencing...
In this study, we investigated the genomic changes in a major methicillin-resistant (MRSA) clone following a significant outbreak at a hospital. Whole-genome sequencing of MRSA isolates was utilized to explore the genomic evolution of post-outbreak MRSA strains. The epidemicity of the clone declined over time, coinciding with the introduction of multimodal infection control measures. A genome-wide association study (GWAS) identified multiple genes significantly associated with either high or low epidemic success, indicating alterations in mobilome, virulence, and defense mechanisms. Random Forest models pinpointed a gene related to fibrinogen binding as the most influential predictor of epidemicity. The decline of the MRSA clone may be attributed to various factors, including the implementation of new infection control measures, single nucleotide polymorphisms accumulation, and the genetic drift of a given clone. This research underscores the complex dynamics of MRSA clones, emphasizing the multifactorial nature of their evolution. The decline in epidemicity seems linked to alterations in the clone's genetic profile, with a probable shift towards decreased virulence and adaptation to long-term carriage. Understanding the genomic basis for the decline of epidemic clones is crucial to develop effective strategies for their surveillance and management, as well as to gain insights into the evolutionary dynamics of pathogen genomes.
PubMed: 38934681
DOI: 10.1128/jcm.00203-24 -
MSystems Jun 2024causes both hospital- and community-acquired infections in humans worldwide. Due to the high incidence of infection, is also one of the most sampled and sequenced...
UNLABELLED
causes both hospital- and community-acquired infections in humans worldwide. Due to the high incidence of infection, is also one of the most sampled and sequenced pathogens today, providing an outstanding resource to understand variation at the bacterial subspecies level. We processed and downsampled 83,383 public Illumina whole-genome shotgun sequences and 1,263 complete genomes to produce 7,954 representative substrains. Pairwise comparison of average nucleotide identity revealed a natural boundary of 99.5% that could be used to define 145 distinct strains within the species. We found that intermediate frequency genes in the pangenome (present in 10%-95% of genomes) could be divided into those closely linked to strain background ("strain-concentrated") and those highly variable within strains ("strain-diffuse"). Non-core genes had different patterns of chromosome location. Notably, strain-diffuse genes were associated with prophages; strain-concentrated genes were associated with the vSaβ genome island and rare genes (<10% frequency) concentrated near the origin of replication. Antibiotic resistance genes were enriched in the strain-diffuse class, while virulence genes were distributed between strain-diffuse, strain-concentrated, core, and rare classes. This study shows how different patterns of gene movement help create strains as distinct subspecies entities and provide insight into the diverse histories of important functions.
IMPORTANCE
We analyzed the genomic diversity of , a globally prevalent bacterial species that causes serious infections in humans. Our goal was to build a genetic picture of the different strains of and which genes may be associated with them. We reprocessed >84,000 genomes and subsampled to remove redundancy. We found that individual samples sharing >99.5% of their genome could be grouped into strains. We also showed that a portion of genes that are present in intermediate frequency in the species are strongly associated with some strains but completely absent from others, suggesting a role in strain specificity. This work lays the foundation for understanding individual gene histories of the species and also outlines strategies for processing large bacterial genomic data sets.
PubMed: 38934646
DOI: 10.1128/msystems.00143-24 -
MBio Jun 2024Type III interferon signaling contributes to the pathogenesis of the important human pathogen in the airway. Little is known of the cellular factors important in this...
Type III interferon signaling contributes to the pathogenesis of the important human pathogen in the airway. Little is known of the cellular factors important in this response. Using -green fluorescent protein reporter mice combined with flow cytometry and cellular depletion strategies, we demonstrate that the alveolar macrophage is the primary producer of interferon lambda (IFN-λ) in response to in the airway. Bone marrow chimeras showed reduced bacterial burden in IFN-λ receptor (IFNLR1)-deficient recipient mice, indicative that non-hematopoietic cells were important for pathogenesis, in addition to significant reductions in pulmonary inflammation. These observations were confirmed through the use of an airway epithelial-specific IFNLR knockout mouse. Our data suggest that upon entry to the airway, activates alveolar macrophages to produce type III IFN that is subsequently sensed by the airway epithelium. Future steps will determine how signaling from the epithelium then exerts its influence on bacterial clearance. These results highlight the important, yet sometimes detrimental, role of type III IFN signaling during infection and the impact the airway epithelium plays during host-pathogen interactions.IMPORTANCEThe contribution of type III interferon signaling to the control of bacterial infections is largely unknown. We have previously demonstrated that it contributes to the pathogenesis of acute respiratory infection. In this report, we document the importance of two cell types that underpin this pathogenesis. We demonstrate that the alveolar macrophage is the cell that is responsible for the production of type III interferon and that this molecule is sensed by airway epithelial cells, which impacts both bacterial clearance and induction of inflammation. This work sheds light on the first two aspects of this important pathogenic cascade.
PubMed: 38934617
DOI: 10.1128/mbio.01130-24 -
Biointerphases May 2024This study aims to explore the essential functional requirements associated with controlling the proliferation of microbes in the domain of textiles used in public...
This study aims to explore the essential functional requirements associated with controlling the proliferation of microbes in the domain of textiles used in public health areas. Herein, three antimicrobial agents, specifically iodopropylbutylcarbamate (IPBC), 1-hydroxypyridine-2-thioketone zinc (ZPT), and 2-octyl-3-isothiazolinone (OIT), were chosen for fabric finishing based on their notable effectiveness, minimal toxicity, cost-efficiency, and chemical stability. Utilizing Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) as representative bacterial strains, the Minimum Inhibitory Concentration (MIC50) of individual and combined antimicrobial agents was measured, and their antimicrobial effectiveness was rigorously evaluated. Concurrently, the antimicrobial effectiveness, whiteness, and mechanical durability of the fabric following antimicrobial treatment were thoroughly examined. The results demonstrate that some combinations of the three antimicrobial agents elicit additive effects on both S. aureus and E. coli. Notably, at an equivalent ratio of IPBC, ZPT, and OIT and a total concentration of 0.2 wt. %, the inhibition rates against both bacterial strains surpass 99%. Upon application to nylon fabric, the treated material demonstrates significant antimicrobial properties, with minimal reduction observed in the whiteness and tensile strength of the treated nylon. This study provides practicable strategies relevant to the production of textiles endowed with antimicrobial properties.
Topics: Escherichia coli; Textiles; Staphylococcus aureus; Microbial Sensitivity Tests; Anti-Bacterial Agents; Anti-Infective Agents; Carbamates; Thiazoles
PubMed: 38934562
DOI: 10.1116/6.0003710 -
Small (Weinheim An Der Bergstrasse,... Jun 2024Defective bismuth telluride (BiTe) nanosheets, an artificial nanozyme mimicking haloperoxidase activity (hPOD), show promise as eco-friendly, bactericidal, and...
Defective bismuth telluride (BiTe) nanosheets, an artificial nanozyme mimicking haloperoxidase activity (hPOD), show promise as eco-friendly, bactericidal, and antimicrofouling materials by enhancing cytotoxic hypohalous acid production from halides and HO. Microscopic and spectroscopic characterization reveals that controlled NaOH (upto X = 250 µL) etching of the nearly inactive non-transition metal chalcogenide BiTe nanosheets creates controlled defects (d), such as Bispecies, in d-BiTe-X that induces enhanced hPOD activity. d-BiTe-250 exhibits approximately eight-fold improved hPOD than the as-grown BiTe nanosheets. The antibacterial activity of d-BiTe-250 nanozymes, studied by bacterial viability, show 1, and 45% viability for Staphylococcus aureus and Pseudomonas aeruginosa, respectively, prevalent in marine environments. The hPOD mechanism is confirmed using scavengers, implicating HOBr and singlet oxygen for the effect. The antimicrofouling property of the d-BiTe-250 nanozyme has been studied on Pseudomonas aeruginosa biofilm in a lab setting by multiple assays, and also on titanium (Ti) plates coated with the nanozyme mixed commercial paint, exposed to seawater in a real setting. All studies, including direct microscopic evidence, exhibit inhibition of microfouling, up to ≈73%, in the presence of nanozymes. This approach showcases that defect engineering can induce antibacterial, and antimicrofouling activity in non-transition metal chalcogenides, offering an inexpensive alternative to noble metals.
PubMed: 38934508
DOI: 10.1002/smll.202401929 -
Zeitschrift Fur Naturforschung. C,... Jun 2024A new compound, combrebisbibenzyl () as well as two sterols including stigmasterol () and 3---D-glucopyranoside of -sitosterol () and seven triterpenoids namely mollic...
A new compound, combrebisbibenzyl () as well as two sterols including stigmasterol () and 3---D-glucopyranoside of -sitosterol () and seven triterpenoids namely mollic acid (), oleanolic acid (), ursolic acid (), arjunglucoside I (, arjungenin (), bellericagenin B () and combregenin () were isolated from the root of . Compounds , and AcOEt and MeOH extracts exhibited moderate antioxidant activity with an IC value of 179.32, 185.21, 195.11 197.41 and 170.21 μg/mL, respectively, for reactive oxygen species inhibition and, inhibition percent value of 57.23, 64.52, 53.55, 67.42 and 65.04, respectively, for DPPH free-radical scavenging. The presented a moderate antibacterial activity against with DIZs value of 10.1 ± 0.2 from 800 μg/mL while the others tested strains were not sensitive. However, most of the tested bacteria, (, and ) were moderately sensitive to from 800 μg/mL with DIZs value of 8.2 ± 0.1. From the E. AcOEt, five of the isolated compounds were tested against four bacteria strains using the disc-dilusion method. The results showed that compound and exhibited very good antibacterial activity against all the tested bacteria at the concentration of 30 μg/mL with respective DIZ value of 22.2 and 25.4 for , 20.2 and 30.2 for , 22.3 and 23.1 for and, 22.1 and 24.1 for . This antibacterial activity significantly depends on the concentration.
PubMed: 38934447
DOI: 10.1515/znc-2023-0087 -
ACS Applied Materials & Interfaces Jun 2024Infection and oxidative stress seriously hinder the healing of diabetic wounds, resulting in various serious health and clinical problems. Herein, a sustainable...
Infection and oxidative stress seriously hinder the healing of diabetic wounds, resulting in various serious health and clinical problems. Herein, a sustainable biological hydrogen (H)-producing hyaluronic acid-based hydrogel patch (HAP-Chl) was constructed by loading an imidazolium-based poly(ionic liquid) (PIL) flocculated live Chlorella as a diabetic wound dressing. The PIL can flocculate Chlorella through electrostatic interactions between PIL and Chlorella to form Chlorella agglomerates, endowing the Chlorella in the central agglomerates with the ability to continuously produce H for 24 h under mild conditions. Combining the membrane disruption-related bactericidal mechanism of PIL and the antioxidant properties of the produced H, HAP-Chl was determined to be antibacterial and antioxidant. In addition to exhibiting biocompatible and nontoxic activities, subsequent -infected chronic wound studies revealed that HAP-Chl is capable of promoting the healing of chronic wounds by effectively killing bacteria, reducing extensive ROS, relieving inflammation, and promoting the deposition of mature collagen and angiogenesis. This study provides a new strategy for constructing an sustainable H-producing hydrogel, enabling the formation of novel antibacterial and antioxidant material platforms with potential for wound dressing applications.
PubMed: 38934271
DOI: 10.1021/acsami.4c07104 -
Zeitschrift Fur Naturforschung. C,... Jun 2024Chemical investigation of the fungal endophyte sp. isolated from leaves of , collected in Cameroon, resulted in the previously undescribed 10-membered macrolide, and...
Chemical investigation of the fungal endophyte sp. isolated from leaves of , collected in Cameroon, resulted in the previously undescribed 10-membered macrolide, and two known natural products. The structures of the xylatolides A and B were unambiguously identified by their mass spectra and by extensive 1D and 2D NMR spectroscopic analysis, featuring a 10-membered lactone core structure with oxygenated substituents and an unsubstituted 10-alkyl chain presenting seven carbon atoms. Compounds were screened for their cytotoxic potential against the human HepG2 hepatocellular carcinoma cells and HCT-116 cells (human colon carcinoma cell line). Moreover, the isolated compounds were also assayed against a small panel of sensitive strains including the bacterial species , , and as well as against the fungal species . However, no significant activities were found.
PubMed: 38934215
DOI: 10.1515/znc-2023-0091 -
ChemMedChem Jun 2024Intending to homogenize the biological activities of both quinoxaline and imidazole moieties, the proligand, 1-methyl-3-quinoxaline-imidazolium hexaflurophosphate...
Design, Synthesis and Bioactivity Evaluation of Ag(I)-, Au(I)- and Au(III)-Quinoxaline-Wingtip N-Heterocyclic Carbene Complexes Against Antibiotic Resistant Bacterial Pathogens.
Intending to homogenize the biological activities of both quinoxaline and imidazole moieties, the proligand, 1-methyl-3-quinoxaline-imidazolium hexaflurophosphate (1.HPF6), and [Ag(1)2][PF6], (2); [Au(1)2][PF6], (3); and [Au(1)Cl3], (4) NHC complexes were synthesized. All the synthesized compounds were characterized by elemental analysis, NMR, and UV-Vis spectroscopy. Finally, single crystal X-ray structures revealed a linear geometry for complex 2 whereas a square planar geometry for complex 4. The formation of complex 3 was confirmed and supported by its MS spectra. The antibacterial activities of all the synthesized complexes were investigated against gram-positive bacteria and gram-negative bacteria. The Au(III)-NHC complex, 4 showed the highest antibacterial activity with extremely low MIC values against both the bacterial strains (0.24 µg.mL-1). Monitoring of zeta potential supports the higher activity of complex 4 compared to 2 and 3. ROS production by complex 4 has also been measured in vitro in the CT26 cancer cell lines, which is directly responsible for targetting and killing the bacterial pathogens. Cell cytotoxicity assay using 293T cell lines has been performed to investigate the biocompatibility nature of complex 4. Also, an excellent hemocompatibility was assigned to it from its hemolytic studies, which provide valuable insights into the design of novel antibacterial agents.
PubMed: 38934210
DOI: 10.1002/cmdc.202400236