Evaluations of biocidal potential of Euclea crispa stem bark extract and ability to compromise the integrity of microbial cell membrane

This study evaluates biocidal effect of Euclea crispa stem bark extract and determines time-kill kinetics of its potent fractions as well as membrane attack capability. Susceptibility of the bacterial cells and minimum inhibitory concentrations (MICs) were determined via agar-well diffusion and broth micro-dilution respectively, time-kill kinetics were evaluated at different concentrations over 2-h period and membrane attack potential was evaluated via scanning electron microscopy imaging and measurement of the amount of proteins and nucleic acids released from the cells. Maximum zone of inhibition (22 ± 0.58 mm) was observed for n-butanol and ethyl acetate fractions at 10 mg/ml. The lowest MIC exhibited by n-butanol (0.31 mg/ml) was against Enterococcus faecalis while that of ethyl acetate, n-hexane and aqueous fractions was 0.63 mg/ml against a number of test isolates. After 120 min of contact time at 1 × MIC, ethyl acetate fraction achieved total mortality against Listeria sp. and S. Typhimurium selected as representative isolates and when the concentration was increased to 2 × MIC n-butanol and aqueous fractions achieved total killing against Listeria sp. The SEM images revealed a level of anatomical disruption in the membrane of test isolates. Maximum amount of proteins released from Listeria sp. (0.63 ± 0.004 µg/ml) was by ethyl acetate fract...
Source: Journal of Herbal Medicine - Category: Complementary Medicine Source Type: research

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AbstractThe biofilm-forming ability ofListeria spp. is a concern to the food industry and health sectors. The aim of this study was to verify the inhibitory activity of bacteriocins produced by enterococci (Enterococcus faecium 20, 22 and 24 andEnterococcus faecalis 27) on developing biofilm and preformed biofilm ofListeria species. Bacteriocins were partially purified from cell free supernatant (CFS).L. monocytogenes 2032,L. innocua 2050 andL. ivanovii 2056 were selected to analyse the inhibitory effect of bacteriocins on biofilm biomass (crystal violet staining) and biofilm viability (XTT-reduction). The biomass of the d...
Source: World Journal of Microbiology and Biotechnology - Category: Microbiology Source Type: research
Feixia Zheng1*, Xiuyun Ye1, Xulai Shi1, Zhongdong Lin1, Zuqin Yang1 and Longxiang Jiang2* 1Department of Pediatrics, The Second Affiliated Hospital &Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China 2Department of Respiratory Medicine, Wenzhou Hospital of Integrated Traditional Chinese and Western Medicine, Wenzhou, China Background: Hyponatremia has frequently been described as a common complication associated with bacterial meningitis, though its frequency and clinical course in children with bacterial meningitis are unclear. The present study aimed to investigate the frequen...
Source: Frontiers in Neurology - Category: Neurology Source Type: research
In conclusion, potential biological applications of PF-SeNPs were explored by antibacterial, antifungal, antioxidant and biocompatibility assays. Materials and Methods Chemicals and Reagents Sodium selenite (98%), 2,2-diphenyl-1-picrylhydrazyl (DPPH), 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT), Tween 80, methanol, acetate buffer, tetracycline, nystatin, rhodamine 123, caspase-3 kit, Dulbecco’s modified Eagle media (DMEM), Folin-Ciocalteu reagent, 2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS), Dulbecco’s phosphate buffered saline pH 7.4 (DPBS) and fetal bovine serum (FBS) w...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
This study aimed to evaluate the antimicrobial and anti-QS potential of organic extracts of onion varieties and its representative phenolic compounds quercetin aglycone and quercetin 3-β-D-glucoside in the QS model bacteria Chromobacterium violaceum ATCC 12472, Pseudomonas aeruginosa PAO1, and Serratia marcescens MG1. Three phenolic extracts were obtained: red onion extract in methanol acidified with 2.5% acetic acid (RO-1), white onion extract in methanol (WO-1) and white onion extract in methanol ammonium (WO-2). Quercetin 4-O-glucoside and quercetin 3,4-O-diglucoside were identified as the predominant compounds in ...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
Conclusion Genomic analyses herein performed allowed us to confirm the recently (Pérez-Cataluña et al., 2018a,b) suggested amendment of A. butzleri as Al. butzlerii, comb. nov. Antimicrobial susceptibility tests defined Ab 55 and Ab 6V strains as resistant to vancomycin, tetracyclin, nalidixic acid (only Ab 55 whereas Ab 6V is intermediate resistant), erythromycin, and β-lactam antibiotics. Moreover, in our strains isolated from shellfish, we identified numerous virulence, antibiotic, and heavy metal resistance determinants, also additional to those previously found in the genome sequenced A. butzleri ...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
Abstract We used a green sol-gel synthesis method to fabricate a novel nanoporous copper aluminosilicate (CAS) material. Nanoporous CAS was characterized using X-ray powder diffraction (XRD), field emission transmission and scanning electron microscopies (FE-TEM/FE-SEM), Fourier transform infrared (FTIR) spectroscopy, and optical analyses. The CAS was also evaluated for use as a promising disinfectant for the inactivation of waterborne pathogens. The antimicrobial action and minimum inhibitory concentration (MIC) of this CAS disinfectant were determined against eight microorganisms (Escherichia coli, Salmonella en...
Source: Environmental Science and Pollution Research International - Category: Environmental Health Authors: Tags: Environ Sci Pollut Res Int Source Type: research
This study aims to examine the inhibitory effects of the bacteriocin CHQS, produced by Enterococcus faecalis TG2, and its mode of action against Listeria ivanovii DSMZ 20750T, which is one of the pathogens sensitive to CHQS. The minimum inhibitory concentration, minimum bactericide concentration and time-inhibition curves were measured to confirm the strong effects of CHQS on L. ivanovii DSMZ 20750T, and its antibacterial mode of action was studied by observing the changes in cell membrane permeability, integrity, and proton motive force. The minimum inhibitory concentration and minimum bactericide concentration of CHQS we...
Source: Food Control - Category: Food Science Source Type: research
C, Capita R, Alonso-Calleja C Abstract The biofilms formed by Salmonella Hadar (SH174), Listeria monocytogenes (LM6), methicillin-resistant Staphylococcus aureus (MRSA125) and vancomycin-resistant Enterococcus faecium (VRE61s) on polystyrene and glass after 24 h and 72 h of incubation at 37 °C were examined by confocal laser scanning microscopy (CLSM) after staining with SYTO9 and propidium iodide (PI). A lower average biovolume (P 
Source: Food Microbiology - Category: Food Science Authors: Tags: Food Microbiol Source Type: research
Publication date: 1 August 2018 Source:Materials Chemistry and Physics, Volume 214 Author(s): N. Elkhoshkhany, Ola Essam, Amira M. Embaby Antibacterial tellurite glass system doped with ZnO was synthesized by the melt-quenching method. The physical and structural characteristics of the glass were studied. The change in the structure was studied using the Fourier Transform Infrared (FTIR) spectra. Transmission studies were performed on the samples in the range (200–800 nm). Characteristics glass temperatures were determined by using Differential Scanning Calorimetry (DSC) in the temperature range (200–600&...
Source: Materials Chemistry and Physics - Category: Materials Science Source Type: research
Abstract The aim of this study was to compare the antibacterial properties of the surfaces of copper plates that were rolled to a thickness of 25 and 100 μm. Differences in topology of 25- and 100-μm-thick copper plates were studied using scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray diffraction (XRD). Antibacterial activity of the copper surfaces was tested against strains of Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Listeria monocytogenes, Salmonella typhimurium, Streptococcus sp. BY1, Enterococcus sp. BY2, and Bacillus cereu...
Source: Applied Microbiology and Biotechnology - Category: Microbiology Authors: Tags: Appl Microbiol Biotechnol Source Type: research
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