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CuS nanostructures with high surface areas were produced through a hydrothermal method using simple materials. These included pure CuS, as well as CuS doped with Fe, Ag, and Mn, as well as dual-doped with Fe/Mn and Ag/Mn. X-ray diffraction (XRD), field-emission scanning electron microscopes (FE-SEM), chemical composition (EDX) analysis, zeta potential, ultraviolet–visible (UV–vis) absorption spectra, and compositional chemicals (FTIR) have been used to characterize the produced nanoparticles. The XRD patterns indicate that the CuS is in hexagonal covellite polycrystalline phases with estimated crystalline sizes of 25.14–14.25 nm. The optical measurements showed that the band gaps ranged from 3.19 to 2.24 eV. The inhibitory effects of pristine CuS, as well as CuS doping with Fe, Ag, and Mn and dual-doping with (Fe/Mn, Ag/Mn), against Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli, were evaluated using the inhibition zone method. All samples exhibited robust antibacterial activity against all strains. The highest level of inhibition against all strains was observed with a concentration of 4 mg/ml of copper sulfide. Out of all the tested samples, (Ag/Mn) dual-doped copper sulfide showed the highest antibacterial activity against both negative-gram and positive-gram bacteria. Hence, (Ag/Mn) dual-doped copper sulfide might be applied as an antibacterial agent with antibiotics to kill and prevent resistance bacterial development. [ABSTRACT FROM AUTHOR]

The synthesis, physicochemical characterizations, and biological investigations on the chelation of the antibiotic medication enoxacin (EXN) with certain vital metal ions, such as platinum(IV), ruthenium(III), and iridium(III) are discussed in this study. These compounds structures were interpreted based on elemental analysis and spectral measurements (FTIR, 1H-NMR, UV-Vis electronic, and XRD). The findings show that there is same coordination pathway for the chelation behavior of enoxacin complexes: a monodentate manner. The Pt(IV), Ru(III), and Ir(III) complexes are coordinated through the N atom of the piperazine ring, which is an unusual mode of coordination for this class of compounds. The dissolved complexes in DMSO were found to have non-electrolyte nature based on their molar conductance measurements. The formula for these complexes is [Pt(EXN)3(H2O)2Cl] (1), [Ru(EXN)3(H2O)3] (2), and [Ir(EXN)3(H2O)3] (3). Using scanning electron microscope (SEM) analysis and Xray powder diffraction (XRD), the nano-scale range of the Pt(IV), Ru(III), and Ir(III) complexes has been determined. Results of in vitro cytotoxicity were examined using MCF-7 cells (human breast cancer cell line) and HepG-2 cells (human hepatocellular carcinoma) that had been grown. The cytotoxic activity of the metal complexes demonstrated a cytotoxic effect against the growth of human breast and liver cancer cell lines. [ABSTRACT FROM AUTHOR]

Background: A major worldwide health issue is the rising frequency of resistance of bacteria.Drug combinations are a winning strategy in fighting resistant bacteria and might help in protecting the existing drugs.Monolaurin is natural compound extracted from coconut oil and has a promising antimicrobial activity against Staphylococcus.aureus. This study aims to examine the efficacy of monolaurin both individually and in combination with β-lactam antibiotics against Staphylococcus aureus isolates. Methods: Agar dilution method was used for determination of minimum inhibitory concentration (MIC) of monolaurin against S.aureus isolates. Scanning electron microscope (SEM) was used to detect morphological changes in S.aureus after treatment with monolaurin. Conventional and Real-time Polymerase chain reaction (RT-PCR) were performed to detect of beta-lactamase (blaZ) gene and its expressional levels after monolaurin treatment. Combination therapy of monolaurin and antibiotics was assessed through fractional inhibitory concentration and time-kill method. Results: The antibacterial activity of monolaurin was assessed on 115 S.aureus isolates, the MIC of monolaurin were 250 to 2000 µg/ml. SEM showed cell elongation and swelling in the outer membrane of S.aureus in the prescence of 1xMIC of monolaurin. blaZ gene was found in 73.9% of S.aureus isolates. RT-PCR shows a significant decrease in of blaZ gene expression at 250 and 500 µg/ml of monolaurin. Synergistic effects were detected through FIC method and time killing curve. Combination therapy established a significant reduction on the MIC value. The collective findings from the antibiotic combinations with monolaurin indicated synergism rates ranging from 83.3% to 100%.In time-kill studies, combination of monolaurin and β-lactam antibiotics produced a synergistic effect. Conclusion: This study showed that monolaurin may be a natural antibacterial agent against S. aureus, and may be an outstanding modulator of β-lactam drugs. The concurrent application of monolaurin and β-lactam antibiotics, exhibiting synergistic effects against S. aureus in vitro, holds promise as potential candidates for the development of combination therapies that target particularly, patients with bacterial infections that are nearly incurable. [ABSTRACT FROM AUTHOR]

The development of antibiotic-resistant microorganisms is a major global health concern. Recently, there has been an increasing interest in antimicrobial peptides as a therapeutic option. This study aimed to evaluate the triple-action (broad-spectrum antibacterial, anti-biofilm, and anti-quorum sensing activities) of melittin, a membrane-active peptide present in bee venom. The minimum inhibitory concentration and minimum bactericidal concentration of the melittin were determined using the microdilution method and agar plate counting. Growth curve analysis revealed that melittin showed a concentration-dependent antibacterial activity. Scanning electron microscope analysis revealed that melittin treatment altered the morphology. Confocal laser scanning microscope revealed that melittin increased the membrane permeability and intracellular ROS generation in bacteria, all of which contribute to bacterial cell death. In addition, the crystal violet (CV) assay was used to test the anti-biofilm activity. The CV assay demonstrated that melittin inhibited biofilm formation and eradicated mature biofilms. Biofilm formation mediated by quorum sensing (QS) plays a major role in this regard, so molecular docking and molecular dynamics analysis confirmed that melittin interacts with LasR receptors through hydrogen bonds, and further evaluates the anti-QS activity of melittin through the production of virulence factors (pyocyanin, elastase, and rhamnolipid), exopolysaccharides secretion, and bacterial motility, that may be the key to inhibiting the biofilm formation mechanism. The present findings highlight the promising role of melittin as a broad-spectrum antibacterial, anti-biofilm agent, and potential QS inhibitor, providing a new perspective and theoretical basis for the development of alternative antibiotics. [ABSTRACT FROM AUTHOR]

The emergence of antibiotic‐resistant bacterial infections is a principal threat to global health. Functionalization of nanomaterial with antibiotics is known as a useful method for increasing the effectiveness of existing antibiotics. In this study, vancomycin‐functionalized ZnFe2O4 nanocomposite (ZnFe2O4@Cell@APTES@Van) was synthesized, and its functional groups and particle size were characterized using Fourier‐transform infrared spectroscopy, thermogravimetric analysis, dynamic light scattering, scanning electron microscope, and transmission electron microscopy. The antibacteria activity of the synthesized nanocomposite was evaluated using minimum inhibitory concentration and minimum bactericidal concentration against Escherichia coli, Staphylococcus aureus, and methicillin‐resistant Staphylococcus aureus (MRSA). Cytotoxicity assay was done by 2,3‐bis‐(2‐methoxy‐4‐nitro‐5‐sulfophenyl)‐2H‐tetrazolium‐5‐carboxanilide method. Characterization analyses of synthesized nanocomposite confirmed the binding of vancomysin on the surface of ZnFe2O4@Cell@APTES. Nanocomposite exhibited an aggregated semi‐spherical structure with hydrodynamic radii of ∼382 nm. In vitro antibacterial activity test showed that vancomycin and vancomycin functionalized ZnFe2O4 have no antibacterial effect against E. coli. S. aureus was sensitive to vancomycin and ZnFe2O4@Cell@APTES@Van NPs and ZnFe2O4 NPs did not improve vancomycin antibacterial activity against these bacteria. MRSA is resistant to vancomycin while ZnFe2O4@Cell@APTES@Van NPs was efficient in inhibiting MRSA growth. In summary, this study showed that attachment of vancomycin to ZnFe2O4 NPs was increased its antibacterial activity against MRSA. [ABSTRACT FROM AUTHOR]

Nanoparticles of zinc selenide (ZnSe) were produced by an innovative, uncomplicated, and extremely rapid process that took no longer than a few seconds. For the production of zinc ions, zinc chloride was utilized, and selenium was used for the production of selenium ions. The effect of Zn to Se ions ratio on optical properties has been examined. The prepared nanoparticles were tested and characterized by using transmission electron microscope TEM, scanning electron microscope SEM and UV–Visible spectroscopy. The morphological results revealed that the ZnSe has a spherical shape with mean diameter around 15 nm and the band gap of the ZnSe increases with increasing the Zn content in the sample. The prepared materials were tested as antibacterial agent. [ABSTRACT FROM AUTHOR]

Propionibacterium acnes (P. acnes) is an anaerobic and gram-positive bacterium involved in the pathogenesis and inflammation of acne vulgaris. This study particularly focuses on the antimicrobial effect of Lacticaseibacillus paracasei LPH01 against P. acnes , a bacterium that causes acne vulgaris. Fifty-seven Lactobacillus strains were tested for their ability to inhibit P. acnes growth employing the Oxford Cup and double dilution methods. The cell-free supernatant (CFS) of L. paracasei LPH01 demonstrated a strong inhibitory effect, with an inhibition zone diameter of 24.65 ± 0.27 mm and a minimum inhibitory concentration of 12.5 mg/mL. Among the CFS, the fraction over 10 kDa (CFS-10) revealed the best antibacterial effect. Confocal laser scanning microscopes and flow cytometry showed that CFS-10 could reduce cell metabolic activity and cell viability and destroy the integrity and permeability of the cell membrane. A scanning electron microscope revealed that bacterial cells exhibited obvious morphological and ultrastructural changes, which further confirmed the damage of CFS-10 to the cell membrane and cell wall. Findings demonstrated that CFS-10 inhibited the conversion of triglycerides, decreased the production of free fatty acids, and down-regulated the extracellular expression of the lipase gene. This study provides a theoretical basis for the metabolite of L. paracasei LPH01 as a potential antibiotic alternative in cosmeceutical skincare products. • MIC of L. paracasei LPH01 CFS was 12.5 mg/mL against P. acnes. • CFS was resistant to heat and acid, and not easily degraded by proteases. • Above 10 kDa CFS (CFS-10) exhibited the highest antibacterial activity. • CFS-10 disrupted the cell membrane structure of P. acnes. • CFS-10 significantly inhibited the expression of extracellular lipase gene. [ABSTRACT FROM AUTHOR]