Displaying publications 81 - 100 of 139 in total

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  1. Antibiotic resistance, plasmid profile and RAPD-PCR analysis of enteropathogenic Escherichia coli (EPEC) clinical isolates
    Wan KF, Radu S, Cheah YK, Benjamin PG, Ling CM, Hon SF, et al.
    Southeast Asian J. Trop. Med. Public Health, 2003 Sep;34(3):620-6.
    PMID: 15115139
    Enteropathogenic Escherichia coli (EPEC) is a leading cause of diarrhea among infants in developing countries. A total of 38 EPEC isolates, obtained from diarrhea patients of Hospital Miri, Sarawak, were investigated through plasmid profile, antibiotic resistance and randomly amplified polymorphic DNA (RAPD) analysis. From the 8 types of antibiotics used, all isolates were 100% resistant to furoxime, cephalothin and sulphamethoxazole and showed high multiple antibiotic resistant (MAR) indexes, ranging from 0.5 to 1.0. In plasmid profiling, 22 isolates (58%) showed the presence of one or more plasmids in the range 1.0 to 30.9 mDa. The dendrogram obtained from the results of the RAPD-PCR discriminated the isolates into 30 single isolates and 3 clusters at the level of 40% similarity. The EPEC isolates were highly diverse, as shown by their differing plasmid profiles, antibiotic resistance patterns and RAPD profiles.
    Matched MeSH terms: Escherichia coli/drug effects
  2. Surveillance of antibiotic resistance in South East Asia
    Williams JD, Moosdeen F, Teoh-Chan CH, Lim VK, Jayanetra P
    Eur J Epidemiol, 1989 Jun;5(2):207-13.
    PMID: 2504618
    Antibiotic resistance in Gram-negative bacteria, particularly Salmonella and Shigella, requires surveillance worldwide. This study describes results of surveys in Hong Kong, Bangkok and Kuala Lumpur. All strains were isolated in hospitals which have large community catchment areas in addition to specialised hospital units. The prevalence of resistant strains was high in all areas. Gram-negative bacteria such as Enterobacter associated with hospital infections were resistant to penicillins and cephalosporins, with gentamicin resistance ranging from about 20% in Kuala Lumpur and Hong Kong, to 35% in Bangkok. Ninety-seven percent of Shigella isolated in Thailand were resistant to ampicillin. About 10% of Salmonella were resistant to chloramphenicol in all three centres.
    Matched MeSH terms: Escherichia coli/drug effects
  3. Magnesium-zinc scaffold loaded with tetracycline for tissue engineering application: In vitro cell biology and antibacterial activity assessment
    Dayaghi E, Bakhsheshi-Rad HR, Hamzah E, Akhavan-Farid A, Ismail AF, Aziz M, et al.
    Mater Sci Eng C Mater Biol Appl, 2019 Sep;102:53-65.
    PMID: 31147024 DOI: 10.1016/j.msec.2019.04.010
    Recently, porous magnesium and its alloys are receiving great consideration as biocompatible and biodegradable scaffolds for bone tissue engineering application. However, they presented poor antibacterial performance and corrosion resistance which limited their clinical applications. In this study, Mg-Zn (MZ) scaffold containing different concentrations of tetracycline (MZ-xTC, x = 1, 5 and 10%) were fabricated by space holder technique to meet the desirable antibacterial activity and corrosion resistance properties. The MZ-TC contains total porosity of 63-65% with pore sizes in the range of 600-800 μm in order to accommodate bone cells. The MZ scaffold presented higher compressive strength and corrosion resistance compared to pure Mg scaffold. However, tetracycline incorporation has less significant effect on the mechanical and corrosion properties of the scaffolds. Moreover, MZ-xTC scaffolds drug release profiles show an initial immediate release which is followed by more stable release patterns. The bioactivity test reveals that the MZ-xTC scaffolds are capable of developing the formation of HA layers in simulated body fluid (SBF). Next, Staphylococcus aureus and Escherichia coli bacteria were utilized to assess the antimicrobial activity of the MZ-xTC scaffolds. The findings indicate that those scaffolds that incorporate a high level concentration of tetracycline are tougher against bacterial organization than MZ scaffolds. However, the MTT assay demonstrates that the MZ scaffolds containing 1 to 5% tetracycline are more effective to sustain cell viability, whereas MZ-10TC shows some toxicity. The alkaline phosphatase (ALP) activity of the MZ-(1-5)TC was considerably higher than that of MZ-10TC on the 3 and 7 days, implying higher osteoblastic differentiation. All the findings suggest that the MZ-xTC scaffolds containing 1 to 5% tetracycline is a promising candidate for bone tissue healing due to excellent antibacterial activity and biocompatibility.
    Matched MeSH terms: Escherichia coli/drug effects
  4. Antibacterial and cytotoxic effect of honey mediated copper nanoparticles synthesized using ultrasonic assistance
    Ismail NA, Shameli K, Wong MM, Teow SY, Chew J, Sukri SNAM
    Mater Sci Eng C Mater Biol Appl, 2019 Nov;104:109899.
    PMID: 31499959 DOI: 10.1016/j.msec.2019.109899
    In this study, a comparative study of effect using honey on copper nanoparticles (Cu-NPs) via simple, environmentally friendly process and inexpensive route was reported. Honey and ascorbic acid act as stabilizing and reducing agents with the assistance of sonochemical method. The products were characterized using UV-visible (UV-vis) spectroscopy, X-Ray Diffraction (XRD), High-Resolution Transmission Electron Microscopy (HRTEM), Field-Emission Scanning Electron Microscopy (FESEM) and Fourier Transform Infrared (FTIR) spectroscopy. The reddish brown colour demonstrated the formation of Cu-NPs and UV-visible proved the plasmon resonance of Cu-NPs. XRD also confirmed a highly pure Cu-NPs obtained with absence of copper oxide in which the structure is crystalline. The spherical size of the Cu-NPs was acquire in the presence of honey which is 3.68 ± 0.78 nm with narrow particle distribution. The antibacterial activity was seen against gram-positive and gram-negative bacteria which are Enterococcus faecalis (E. faecalis) and Escherichia coli (E. coli). At higher concentration of Cu-NPs, they were more effective in killing both bacteria. The Cu-NPs without and with honey exhibited toxicities toward normal and cancerous cells. However, Cu-NPs without honey showed more potent killing activity against normal and cancer cells.
    Matched MeSH terms: Escherichia coli/drug effects
  5. Fulltext Inactivating pathogenic bacteria in greywater by biosynthesized Cu/Zn nanoparticles from secondary metabolite of Aspergillus iizukae; optimization, mechanism and techno economic analysis
    Noman E, Al-Gheethi A, Talip BA, Mohamed R, Kassim AH
    PLoS One, 2019;14(9):e0221522.
    PMID: 31513594 DOI: 10.1371/journal.pone.0221522
    The inactivation of antibiotic resistant Escherichia coli (Gram negative) and Staphylococcus aureus (Gram positive) seeded in greywater by bimetallic bio-nanoparticles was optimized by using response surface methodology (RSM). The bimetallic nanoparticles (Cu/Zn NPs) were synthesized in secondary metabolite of a novel fungal strain identified as Aspergillus iizukae EAN605 grown in pumpkin medium. Cu/Zn NPs were very effective for inhibiting growth of E. coli and S. aureus. The maximum inactivation was optimized with 0.028 mg mL-1 of Cu/Zn NPs, at pH 6 and after 60 min, at which the reduction of E. coli and S. aureus was 5.6 vs. 5.3 and 5.2 vs. 5.4 log reduction for actual and predicted values, respectively. The inactivation mechanism was described based on the analysis of untreated and treated bacterial cells by Field emission scanning electron microscopy (FESEM), Energy Dispersive X-Ray Spectroscopy (EDS), Atomic Force Microscopy (AFM) revealed a damage in the cell wall structure due to the effect of Cu/Zn NPs. Moreover, the Raman Spectroscopy showed that the Cu/Zn NPs led to degradation of carbohydrates and amino structures on the bacteria cell wall. The Fourier transform infrared spectroscopy (FTIR) analysis confirmed that the destruction take place in the C-C bond of the functional groups available in the bacterial cell wall. The techno economic analysis revealed that the biosynthesis Cu/Zn NPs is economically feasible. These findings demonstrated that Cu/Zn NPs can effectively inhibit pathogenic bacteria in the greywater.
    Matched MeSH terms: Escherichia coli/drug effects
  6. Manganese disulfide-silicon dioxide nano-material: Synthesis, characterization, photocatalytic, antioxidant and antimicrobial studies
    Ashraf MA, Peng WX, Fakhri A, Hosseini M, Kamyab H, Chelliapan S
    J. Photochem. Photobiol. B, Biol., 2019 Sep;198:111579.
    PMID: 31401316 DOI: 10.1016/j.jphotobiol.2019.111579
    The sol-gel/ultrasonically rout produced the novel MnS2-SiO2 nano-hetero-photocatalysts with the various ratio of MnS2. Prepared nano-catalyst were investigated in the photo-degradation of methylene blue under UV light illumination. Structural and optical attributes of as-prepared nano-catalysts were evaluated by X-ray diffraction and photoelectron spectroscopy. The morphological were studied by scanning electron microscopy-EDS, and dynamic light scattering. The diffuse reflectance spectroscopy was applied to examine the band gap energy. The Eg values of SiO2, MnS2-SiO2-0, MnS2-SiO2-1, and MnS2-SiO2-2 nanocomposites are 6.51, 3.85, 3.17, and 2.67 eV, respectively. The particle size of the SiO2 and MnS2-SiO2-1 nanocomposites were 100.0, and 65.0 nm, respectively. The crystallite size values of MnS2-SiO2-1 were 52.21 nm, and 2.9 eV, respectively. MnS2-SiO2 nano-photocatalyst was recognized as the optimum sample by degrading 96.1% of methylene blue from water. Moreover, the influence of pH of the solution, and contact time as decisive factors on the photo-degradation activity were investigated in this project. The optimum data for pH and time were found 9 and 60 min, respectively. The photo-degradation capacity of MnS2-SiO2-2 is improved (96.1%) due to the low band gap was found from UV-vis DRS. The antimicrobial data of MnS2-SiO2 were studied and demonstrated that the MnS2-SiO2 has fungicidal and bactericidal attributes.
    Matched MeSH terms: Escherichia coli/drug effects
  7. Identification of Antibacterial Molecule(s) from Animals Living in Polluted Environments
    Winnie FYM, Siddiqui R, Sagathevan K, Khan NA
    Curr Pharm Biotechnol, 2020;21(5):425-437.
    PMID: 31577204 DOI: 10.2174/1389201020666191002153435
    BACKGROUND: Snakes feed on germ-infested rodents, while water monitor lizards thrive on rotten matter in unhygienic conditions. We hypothesize that such creatures survive the assault of superbugs and are able to fend off disease by producing antimicrobial substances. In this study, we investigated the potential antibacterial activity of sera/lysates of animals living in polluted environments.

    METHODS: Snake (Reticulatus malayanus), rats (Rattus rattus), water monitor lizard (Varanus salvator), frog (Lithobates catesbeianus), fish (Oreochromis mossambicus), chicken (Gallus gallus domesticus), and pigeon (Columba livia) were dissected and their organ lysates/sera were collected. Crude extracts were tested for bactericidal effects against neuropathogenic E. coli K1, methicillin-resistant Staphylococcus aureus (MRSA), Streptococcus pyogenes, Pseudomonas aeruginosa, Bacillus cereus and Klebsiella pneumoniae. To determine whether lysates/sera protect human cells against bacterialmediated damage, cytotoxicity assays were performed by measuring lactate dehydrogenase release as an indicator of cell death. Lysates/sera were partially characterized using heat-treatment and pronasetreatment and peptide sequences were determined using the Liquid Chromatography Mass Spectrometry (LC-MS).

    RESULTS: Snake and water monitor lizard sera exhibited potent broad-spectrum bactericidal effects against all bacteria tested. Heat inactivation and pronase-treatment inhibited bactericidal effects indicating that activity is heat-labile and pronase-sensitive suggesting that active molecules are proteinaceous in nature. LCMS analyses revealed the molecular identities of peptides.

    CONCLUSION: The results revealed that python that feeds on germ-infested rodents and water monitor lizards that feed on rotten organic waste possess antibacterial activity in a heat-sensitive manner and several peptides were identified. We hope that the discovery of antibacterial activity in the sera of animals living in polluted environments will stimulate research in finding antibacterial agents from unusual sources as this has the potential for the development of novel strategies in the control of infectious diseases.

    Matched MeSH terms: Escherichia coli/drug effects
  8. Inflammation targeted chitosan-based hydrogel for controlled release of diclofenac sodium
    Gull N, Khan SM, Butt OM, Islam A, Shah A, Jabeen S, et al.
    Int J Biol Macromol, 2020 Nov 01;162:175-187.
    PMID: 32562726 DOI: 10.1016/j.ijbiomac.2020.06.133
    Inflammation is a key challenge in the treatment of chronic diseases. Spurred by topical advancement in polymer chemistry and drug delivery, hydrogels that release a drug in temporal, spatial and dosage controlled fashion have been trendy. This research focused on the fabrication of hydrogels with controlled drug release properties to control inflammation. Chitosan and polyvinyl pyrrolidone were used as base polymers and crosslinked with epichlorohydrin to form hydrogel films by solution casting technique. Prepared hydrogels were analyzed by swelling analysis in deionized water, buffer and electrolyte solutions and gel fraction. Functional groups confirmation and development of new covalent and hydrogen bonds, thermal stability (28.49%) and crystallinity were evaluated by FTIR, TGA and WAXRD, respectively. Rheological properties including gel strength and yield stress, elasticity (2309 MPa), porosity (75%) and hydrophilicity (73°) of prepared hydrogels were also evaluated. In vitro studies confirmed that prepared hydrogels have good biodegradability, excellent antimicrobial property and admirable cytotoxicity. Drug release profile (87.56% in 130 min) along with the drug encapsulation efficiency (84%) of prepared hydrogels was also studied. These results paved the path towards the development of hydrogels that can release the drugs with desired temporal patterns.
    Matched MeSH terms: Escherichia coli/drug effects*
  9. Fulltext Artocarpus altilis extracts as a food-borne pathogen and oxidation inhibitors: RSM, COSMO RS, and molecular docking approaches
    Ahmad MN, Karim NU, Normaya E, Mat Piah B, Iqbal A, Ku Bulat KH
    Sci Rep, 2020 06 12;10(1):9566.
    PMID: 32533034 DOI: 10.1038/s41598-020-66488-7
    Lipid oxidation and microbial contamination are the major factors contributing to food deterioration. Food additives like antioxidants and antibacterials can prevent food spoilage by delaying oxidation and preventing the growth of bacteria. Artocarpus altilis leaves exhibited biological properties that suggested its use as a new source of natural antioxidant and antimicrobial. Supercritical fluid extraction (SFE) was used to optimize the extraction of bioactive compounds from the leaves using response surface methodology (yield and antioxidant activity). The optimum SFE conditions were 50.5 °C temperature, 3784 psi pressure and 52 min extraction time. Verification test results (Tukey's test) showed that no significant difference between the expected and experimental DPPH activity and yield value (99%) were found. Gas-chromatography -mass spectrometry (GC-MS) analysis revealed three major bioactive compounds existed in A. altilis extract. The extract demonstrated antioxidant and antibacterial properties with 2,3-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, ferric reducing ability of plasma (FRAP), hydroxyl radical scavenging activity, tyrosinase mushrrom inhibition of 41.5%, 8.15 ± 1.31 (µg of ascorbic acid equivalents), 32%, 37% and inhibition zone diameter of 0.766 ± 0.06 cm (B. cereus) and 1.27 ± 0.12 cm (E. coli). Conductor like screening model for real solvents (COSMO RS) was performed to explain the extraction mechanism of the major bioactive compounds during SFE. Molecular electrostatic potential (MEP) shows the probability site of nucleophilic and electrophilic attack during bacterial inhibition. Based on molecular docking study, non-covalent interactions are the main interaction occurring between the major bioactive compounds and bacteria (antibacterial inhibition).
    Matched MeSH terms: Escherichia coli/drug effects
  10. Fulltext Growth profile and SEM analyses of Candida albicans and Escherichia coli with Hymenocallis littoralis (Jacq.) Salisb leaf extract
    Rosli N, Sumathy V, Vikneswaran M, Sreeramanan S
    Trop Biomed, 2014 Dec;31(4):871-9.
    PMID: 25776614 MyJurnal
    Hymenocallis littoralis (Jacq.) Salisb (Melong kecil) commonly known as 'Spider Lily' is an herbaceous plant from the family Amaryllidaceae. Study was carried out to determine the effect of H. littoralis leaf extract on the growth and morphogenesis of two pathogenic microbes, Candida albicans and Escherichia coli. The leaf extract displayed favourable anticandidal and antibacterial activity with a minimum inhibition concentration (MIC) of 6.25 mg/mL. Time kill study showed both microbes were completely killed after treated with leaf extract at 20 h. Both microbes' cell walls were heavily ruptured based on scanning electron microscopy (SEM) analysis. The significant anticandidal and antibacterial activities showed by H. littoralis leaf extract suggested the potential antimicrobial agent against C. albicans and E. coli.
    Matched MeSH terms: Escherichia coli/drug effects*
  11. Antibacterial efficacy of quaternized chitosan/poly (vinyl alcohol) nanofiber membrane crosslinked with blocked diisocyanate
    Wu JY, Ooi CW, Song CP, Wang CY, Liu BL, Lin GY, et al.
    Carbohydr Polym, 2021 Jun 15;262:117910.
    PMID: 33838797 DOI: 10.1016/j.carbpol.2021.117910
    N-[(2-hydroxyl-3-trimethylammonium) propyl] chitosan chloride (HTCC), which is a type of chitosan derivative with quaternary ammonium groups, possesses a higher antibacterial activity as compared to the pristine chitosan. The nanofiber membranes made of HTCC are attractive for applications demanding for antibacterial function. However, the hydrophilic nature of HTCC makes it unsuitable for electrospinning of nanofibers. Hence, biodegradable polyvinyl alcohol (PVA) was proposed as an additive to improve the electrospinnability of HTCC. In this work, PVA/HTCC nanofiber membrane was crosslinked with the blocked diisocyanate (BI) to enhance the stability of nanofiber membrane in water. Microbiological assessments showed that the PVA/HTCC/BI nanofiber membranes possessed a good antibacterial efficacy (∼100 %) against E. coli. Moreover, the biocompatibility of PVA/HTCC/BI nanofiber membrane was proven by the cytotoxicity test on mouse fibroblasts. These promising results indicated that the PVA/HTCC/BI nanofiber membrane can be a promising material for food packaging and as a potential wound dressing for skin regeneration.
    Matched MeSH terms: Escherichia coli/drug effects
  12. Fulltext Chemical Profile, Antioxidant Properties and Antimicrobial Activities of Malaysian Heterotrigona itama Bee Bread
    Suleiman JB, Mohamed M, Abu Bakar AB, Nna VU, Zakaria Z, Othman ZA, et al.
    Molecules, 2021 Aug 15;26(16).
    PMID: 34443531 DOI: 10.3390/molecules26164943
    The aim of the study was to determine the chemical profile, antioxidant properties and antimicrobial activities of Heterotrigona itama bee bread from Malaysia. The pH, presence of phytochemicals, antioxidant properties, total phenolic content (TPC) and total flavonoid content (TFC), as well as antimicrobial activities, were assessed. Results revealed a decrease in the pH of bee bread water extract (BBW) relative to bee bread ethanolic extract (BBE) and bee bread hot water extract (BBH). Further, alkaloids, flavonoids, phenols, tannins, saponins, terpenoids, resins, glycosides and xanthoproteins were detected in BBW, BBH and BBE. Also, significant decreases in TPC, TFC, DPPH activity and FRAP were detected in BBW relative to BBH and BBE. We detected phenolic acids such as gallic acid, caffeic acid, trans-ferulic acid, trans 3-hydroxycinnamic acid and 2-hydroxycinnamic acid, and flavonoids such as quercetin, kaempferol, apigenin and mangiferin in BBE using high-performance liquid chromatography analysis. The strongest antimicrobial activity was observed in Klebsilla pneumonia (MIC50 1.914 µg/mL), followed by E. coli (MIC50 1.923 µg/mL), Shigella (MIC50 1.813 µg/mL) and Salmonella typhi (MIC50 1.617 µg/mL). Bee bread samples possess antioxidant and antimicrobial properties. Bee bread contains phenolic acids and flavonoids, and could be beneficial in the management and treatment of metabolic diseases.
    Matched MeSH terms: Escherichia coli/drug effects
  13. Preparation and properties of cellulose nanocomposite films with in situ generated copper nanoparticles using Terminalia catappa leaf extract
    Muthulakshmi L, Rajini N, Nellaiah H, Kathiresan T, Jawaid M, Rajulu AV
    Int J Biol Macromol, 2017 Feb;95:1064-1071.
    PMID: 27984140 DOI: 10.1016/j.ijbiomac.2016.09.114
    In the present work, copper nanoparticles (CuNPs) were in situ generated inside cellulose matrix using Terminalia catappa leaf extract as a reducing agent. During this process, some CuNPs were also formed outside the matrix. The CuNPs formed outside the matrix were observed with transmission electron microscope (TEM) and scanning electron microscope (SEM). Majority of the CuNPs formed outside the matrix were in the size range of 21-30nm. The cellulose/CuNP composite films were characterized by Fourier transform infrared spectroscopic, X-Ray diffraction and thermogravimetric techniques. The crystallinity of the cellulose/CuNP composite films was found to be lower than that of the matrix indicating rearrangement of cellulose molecules by in situ generated CuNPs. Further, the expanded diffractogram of the composite films indicated the presence of a mixture of Cu, CuO and Cu2O nanoparticles. The thermal stability of the composites was found to be lower than that of the composites upto 350°C beyond which a reverse trend was observed. This was attributed to the catalytic behaviour of CuNPs for early degradation of the composites. The composite films possessed sufficient tensile strength which can replace polymer packaging films like polyethylene. Further, the cellulose/CuNP composite films exhibited good antibacterial activity against E.coli bacteria.
    Matched MeSH terms: Escherichia coli/drug effects
  14. Enteropathogenic Escherichia coli diarrhoea in Malaysian children
    Jegathesan M, Singh RB, Kanaganayagy M, Soon LE
    Southeast Asian J. Trop. Med. Public Health, 1975 Mar;6(1):61-7.
    PMID: 1096307
    Matched MeSH terms: Escherichia coli/drug effects
  15. Membrane-lytic actions of sulphonated methyl ester surfactants and implications to bactericidal effect and cytotoxicity
    Pan F, Li Z, Gong H, Petkov JT, Lu JR
    J Colloid Interface Sci, 2018 Dec 01;531:18-27.
    PMID: 30015167 DOI: 10.1016/j.jcis.2018.07.031
    Surfactants are multifunctional molecules widely used in personal care and healthcare formulations to cleanse, help disperse active ingredients (e.g., forming emulsions) and stabilise products. With increasing demands on improving biosafety, there is now mounting pressure to understand how different surfactants elicit toxicities at molecular and cellular levels. This work reports the membrane-lytic behaviour of a group of sulphonated methyl ester (SME) surfactants together with representative conventional surfactants. All surfactants displayed the clear rise of lysis of the model lipid bilayer membranes around their CMCs, but the two ionic surfactants SDS and C12TAB even caused measurable lysis below their CMCs, with membrane-lytic actions increasing with monomer concentration. Furthermore, whilst ionic and nonionic surfactants could achieve full membrane lysis once above their CMCs, this ability was weak from the SME surfactants and decreased with increasing the acyl chain length. In contrast to the conventional anionic surfactants such as SDS and SLES, the protein solubilizing capability of the SME surfactants was also low. On the other hand, MTT assays against 3T3 fibroblast cells and human chondrocyte cells revealed high toxicity from SDS and C12TAB against the other surfactants studied, but the difference between SME and the rest of conventional surfactants was small. Similar behaviour was also observed in their bactericidal effect against E. coli and S. aureus. The trend is broadly consistent with their membrane-lytic behaviour, indicating little selectivity in their cytotoxicity and bactericidal action. These results thus reveal different toxicities implicated from different surfactant head groups. Increase in acyl chain length as observed from SME surfactants could help improve surfactant biocompatibility.
    Matched MeSH terms: Escherichia coli/drug effects*
  16. Synthesis of halogenated azo-aspirin analogues from natural product derivatives as the potential antibacterial agents
    Ngaini Z, Mortadza NA
    Nat Prod Res, 2019 Dec;33(24):3507-3514.
    PMID: 29911437 DOI: 10.1080/14786419.2018.1486310
    Chemical modification of medicines from natural product-based molecules has become of interest in recent years. In this study, a series of halogenated azo derivatives 1a-d were synthesised via coupling reaction, followed by Steglich esterification with aspirin (a natural product derivative) to form azo derivatives 2a-d. While, halogenated azo-aspirin 3a-d were synthesised via direct coupling reaction of aspirin and diazonium salt. Bacteriostatic activity was demonstrated against E. coli and S. aureus via turbidimetric kinetic method. Compound 3a-d showed excellent antibacterial activities against E. coli (MIC 75-94 ppm) and S. aureus (MIC 64-89 ppm) compared to ampicillin (MIC 93 and 124 ppm respectively), followed by 1a-d and 2a-d. The presence of reactive groups of -OH, N=N, C=O and halogens significantly contribute excellent interaction towards E. coli and S. aureus. Molecular dockings analysis of 3a against MIaC protein showed binding free energy of -7.2 kcal/mol (E. coli) and -6.6 kcal/mol (S. aureus).
    Matched MeSH terms: Escherichia coli/drug effects
  17. Elastomeric biocomposite of silver-containing mesoporous bioactive glass and poly(1,8-octanediol citrate): Physiochemistry and in vitro antibacterial capacity in tissue engineering applications
    Pourshahrestani S, Zeimaran E, Kadri NA, Gargiulo N, Jindal HM, Hasikin K, et al.
    Mater Sci Eng C Mater Biol Appl, 2019 May;98:1022-1033.
    PMID: 30812986 DOI: 10.1016/j.msec.2019.01.022
    A novel series of silver-doped mesoporous bioactive glass/poly(1,8-octanediol citrate) (AgMBG/POC) elastomeric biocomposite scaffolds were successfully constructed by a salt-leaching technique for the first time and the effect of inclusion of different AgMBG contents (5, 10, and 20 wt%) on physicochemical and biological properties of pure POC elastomer was evaluated. Results indicated that AgMBG particles were uniformly dispersed in the POC matrix and increasing the AgMBG concentration into POC matrix up to 20 wt% enhanced thermal behaviour, mechanical properties and water uptake ability of the composite scaffolds compared to those from POC. The 20%AgMBG/POC additionally showed higher degradation rate in Tris(hydroxymethyl)-aminomethane-HCl (Tris-HCl) compared with pure POC and lost about 26% of its initial weight after soaking for 28 days. The AgMBG phase incorporation also significantly endowed the resulting composite scaffolds with efficient antibacterial properties against Escherichia coli and Staphylococcus aureus bacteria while preserving their favorable biocompatibility with soft tissue cells (i.e., human dermal fibroblast cells). Taken together, our results suggest that the synergistic effect of both AgMBG and POC make these newly designed AgMBG/POC composite scaffold an attractive candidate for soft tissue engineering applications.
    Matched MeSH terms: Escherichia coli/drug effects
  18. Co-incorporation of graphene oxide/silver nanoparticle into poly-L-lactic acid fibrous: A route toward the development of cytocompatible and antibacterial coating layer on magnesium implants
    Bakhsheshi-Rad HR, Ismail AF, Aziz M, Akbari M, Hadisi Z, Khoshnava SM, et al.
    Mater Sci Eng C Mater Biol Appl, 2020 Jun;111:110812.
    PMID: 32279830 DOI: 10.1016/j.msec.2020.110812
    Magnesium (Mg) alloys present great potential for the development of orthopedic implants, whereas, their high degradation rate and poor antibacterial performance have restricted orthopedic applications. In this work, PLLA/GO-AgNP (poly-L-lactic acid/graphene oxide- silver nanoparticle) with different concentration of GO-AgNPs were deposited on Mg alloy via electrospinning method for enhancement of corrosion resistance and antibacterial performance. The result revealed that incorporation of GO into PLLA fibrous considerably slowed down the degradation rate of Mg alloy substrate and reduced the H2 release rate from the substrate. Also, co-incorporation of GO and AgNPs into PLLA fibrous resulted in substantial escalate in compressive strength after immersion in simulated body fluid (SBF). Antibacterial activity test exhibited that Mg alloy and neat PLLA fibrous presented minimal inhibition area toward Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). In contrast, using PLLA/GO-AgNPs fibrous improved antibacterial performance against both bacteria. Cytocompatibility results indicated that PLLA/GO-AgNPs fibrous with a low amount of GO-AgNPs enhanced cell proliferation and growth while high co-incorporation of GO-AgNPs showed a negative effect on cell proliferation. Taken together, PLLA/1GO-AgNPs fibrous coating shows suitable corrosion resistance, cytocompatibility, and antibacterial function for use in orthopedic applications.
    Matched MeSH terms: Escherichia coli/drug effects
  19. Synthesis of new S-substituted derivatives of 5-[3-(1H-indol-3-yl)propyl]-1,3,4-oxadiazol-2-ylhydrosulfide as suitable antibacterial and anticancer agents with moderate cytotoxicity
    Nazir M, Abbasi MA, Aziz-Ur-Rehman -, Siddiqui SZ, Ali Shah SA, Shahid M, et al.
    Pak J Pharm Sci, 2019 Nov;32(6):2585-2597.
    PMID: 31969290
    In the study presented here, the nucleophilic substitution reaction of 5-[3-(1H-indol-3-yl)propyl]-1,3,4-oxadiazol-2-ylhydrosulfide was carried out with different alkyl/aralkyl halides (5a-r) to form its different S-substituted derivatives (6a-r), as depicted in scheme 1. The structural confirmation of all the synthesized compounds was done by IR, 1H-NMR, 13C-NMR and CHN analysis data. Bacterial biofilm inhibitory activity of all the synthesized compounds was carried out against Bacillus subtilis and Escherichia coli. The anticancer activity of these molecules was ascertained using anti-proliferation (SRB) assay on HCT 116 Colon Cancer Cell lines while the cytotoxicity of these molecules was profiled for their haemolytic potential. From this investigation it was rational that most of the compounds exhibited suitable antibacterial and anticancer potential along with a temperate cytotoxicity.
    Matched MeSH terms: Escherichia coli/drug effects
  20. Synthesis, spectral analysis and biological evaluation of 2-{[(morpholin-4-yl)ethyl]thio}-5-phenyl/aryl-1,3,4-oxadiazole derivatives
    Ur-Rehman A, Khan SG, Naqvi SAR, Ahmad M, Akhtar N, Bokhari TH, et al.
    Pak J Pharm Sci, 2021 Jan;34(1(Special)):441-446.
    PMID: 34275792
    A series of new derivatives of 4-(2-chloroethyl)morpholine hydrochloride (5) were efficiently synthesized. Briefly, different aromatic organic acids (1a-f) were refluxed to acquire respective esters (2a-f) using conc. H2SO4 as catalyst. The esters were subjected to nucleophillic substitution by monohydrated hydrazine to acquire hydrazides (3a-f). The hydrazides were cyclized with CS2 in the presence of KOH to yield corresponding oxadiazoles (4a-f). Finally, the derivatives, 6a-f, were prepared by reacting oxadiazoles (4a-f) with 5 using NaH as activator. Structures of all the derivatives were elucidated through 1D-NMR EI-MS and IR spectral data. All these molecules were subjected to antibacterial and hemolytic activities and showed good antibacterial and hemolytic potential relative to the reference standards.
    Matched MeSH terms: Escherichia coli/drug effects
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