MyMedR

Displaying publications 101 - 120 of 126 in total

Abstract:

Sort:

Valorization of biodiesel side stream waste glycerol for rhamnolipids production by Pseudomonas aeruginosa RS6

Baskaran SM, Zakaria MR, Mukhlis Ahmad Sabri AS, Mohamed MS, Wasoh H, Toshinari M, et al.

Environ Pollut, 2021 Feb 13;276:116742.
PMID: 33621735 DOI: 10.1016/j.envpol.2021.116742

Biodiesel side stream waste glycerol was identified as a cheap carbon source for rhamnolipids (RLs) production which at the same time could improve the management of waste. The present study aimed to produce RLs by using Pseudomonas aeruginosa RS6 utilizing waste glycerol as a substrate and to evaluate their physico-chemicals properties. Fermentation conditions such as temperature, initial medium pH, waste glycerol concentration, nitrogen sources and concentrations resulted in different compositions of the mono- and di-RLs produced. The maximum RLs production of 2.73 g/L was obtained when P. aeruginosa RS6 was grown in a basal salt medium supplemented with 1% waste glycerol and 0.2 M sodium nitrate at 35 °C and pH 6.5. At optimal fermentation conditions, the emulsification index (E24) values of cooking oil, diesel oil, benzene, olive oil, petroleum, and kerosene were all above E24=50%. The surface tension reduction obtained from 72.13 mN/m to 29.4-30.4 mN/m was better than the surface activity of some chemical-based surfactants. The RLs produced possessed antimicrobial activities against Gram-negative and Gram-positive bacteria with values ranging from 37% to 77% of growth inhibition when 1 mg/mL of RLs was used. Concentrations of RLs below 1500 μg/mL did not induce phytotoxicity effects on the tested seeds (Vigna radiata) compared to the chemical-based- surfactant, SDS. Furthermore, RLs tested on zebrafish (Danio rerio) embryos only exhibited low acute toxicity with an LC50 value of 72.97 μg/mL at 48 h of exposure suggesting a green and eco-biochemical worthy of future applications to replace chemical-based surfactants.

Matched MeSH terms: Gram-Positive Bacteria
Fulltext Bioactive Compounds from the Bornean Endemic Plant Goniothalamus longistipetes

Teo SP, Bhakta S, Stapleton P, Gibbons S

Antibiotics (Basel), 2020 Dec 16;9(12).
PMID: 33339285 DOI: 10.3390/antibiotics9120913

The present study aimed to screen plants for bioactive compounds with potential antibacterial activities. In our efforts to evaluate plants from Borneo, we isolated and elucidated the structures of four natural products from the bioactive fraction of a chloroform extract of Goniothalamus longistipetes using various chromatographic and spectroscopic techniques. The bioactive compounds were identified as a known styryllactone, (+)-altholactone ((2S,3R,3aS,7aS)-3-hydroxy-2-phenyl-2,3,3a,7a-tetrahydrobenzo-5(4H)-5-one) (1), a new styryllactone, (2S,3R,3aS,7aS)-3-hydroxy-2-phenyl-2,3,3a,7a-tetrahydrobenzo-5(4H)-5-one) (2) as well as a new alkaloid, 2,6-dimethoxyisonicotinaldehyde (3) and a new alkenyl-5-hydroxyl-phenyl benzoic acid (4). 1 and 4 showed broad-spectrum anti-bacterial activities against Gram-positive and Gram-negative bacteria as well as acid-fast model selected for this study. Compound 2 only demonstrated activities against Gram-positive bacteria whilst 3 displayed selective inhibitory activities against Gram-positive bacterial strains. Additionally, their mechanisms of anti-bacterial action were also investigated. Using Mycobacterium smegmatis as a fast-growing model of tubercle bacilli, compounds 1, 2 and 4 demonstrated inhibitory activities against whole-cell drug efflux and biofilm formation; two key intrinsic mechanisms of antibiotic resistance. Interestingly, the amphiphilic compound 4 exhibited inhibitory activity against the conjugation of plasmid pKM101 in Escherichia coli using a plate conjugation assay. Plasmid conjugation is a mechanism by which Gram-positive and Gram-negative-bacteria acquire drug resistance and virulence. These results indicated that bioactive compounds isolated from Goniothalamus longistipetes can be potential candidates as 'hits' for further optimisation.

Matched MeSH terms: Gram-Positive Bacteria
Fulltext Pentocin MQ1: A Novel, Broad-Spectrum, Pore-Forming Bacteriocin From Lactobacillus pentosus CS2 With Quorum Sensing Regulatory Mechanism and Biopreservative Potential

Wayah SB, Philip K

Front Microbiol, 2018;9:564.
PMID: 29636737 DOI: 10.3389/fmicb.2018.00564

Micrococcus luteus, Listeria monocytogenes, and Bacillus cereus are major food-borne pathogenic and spoilage bacteria. Emergence of antibiotic resistance and consumer demand for foods containing less of chemical preservatives led to a search for natural antimicrobials. A study aimed at characterizing, investigating the mechanism of action and regulation of biosynthesis and evaluating the biopreservative potential of pentocin from Lactobacillus pentosus CS2 was conducted. Pentocin MQ1 is a novel bacteriocin isolated from L. pentosus CS2 of coconut shake origin. The purification strategy involved adsorption-desorption of bacteriocin followed by RP-HPLC. It has a molecular weight of 2110.672 Da as determined by MALDI-TOF mass spectrometry and a molar extinction value of 298.82 M-1 cm-1. Pentocin MQ1 is not plasmid-borne and its biosynthesis is regulated by a quorum sensing mechanism. It has a broad spectrum of antibacterial activity, exhibited high chemical, thermal and pH stability but proved sensitive to proteolytic enzymes. It is potent against M. luteus, B. cereus, and L. monocytogenes at micromolar concentrations. It is quick-acting and exhibited a bactericidal mode of action against its targets. Target killing was mediated by pore formation. We report for the first time membrane permeabilization as a mechanism of action of the pentocin from the study against Gram-positive bacteria. Pentocin MQ1 is a cell wall-associated bacteriocin. Application of pentocin MQ1 improved the microbiological quality and extended the shelf life of fresh banana. This is the first report on the biopreservation of banana using bacteriocin. These findings place pentocin MQ1 as a potential biopreservative for further evaluation in food and medical applications.

Matched MeSH terms: Gram-Positive Bacteria
Fulltext Synergistic effects of Persicaria odorata (daun kesom) leaf extracts with standard antibiotics on pathogenic bacteria

Ridzuan, P.M., Hairul Aini Hamzah, Anis Shah, Norazian Mohd Hassan, Baharudin Roesnita

International Medical Journal Malaysia, 2017;16(2):27-32.
MyJurnal

Antibacterial activity of different types of P. odorata leaf extracts was evaluated in combination with
standard antibiotics. Persicaria. odorata leaves were extracted with n-hexane (n-hex), dichloromethane
(DCM) and methanol (MeOH). Each extract was applied on vancomycin (30µg), erythromycin (15µg) and
gentamicin (10µg) discs, respectively. Disk diffusion method was used to evaluate the synergistic activity of
each combination on Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes,
Streptococcus pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, and Escherichia coli. Minimum
inhibitory concentration (MIC) and gas chromatography mass spectrometry (GCMS) analysis was performed on
the active extract. Synergistic effects seen were mainly from the n-hex+antibiotics combinations, mainly on
the Gram-positive bacteria (7 additive, 5 antagonistic), with MIC range from 50 µg/ml to 100 µg/ml, as well
as Gram-negative bacteria (2 additive, 2 indifferent, 5 antagonistic). In particular, synergism showed by the
combination of n-hex+van were all additive against the susceptible bacteria. DCM extract combination
showed synergistic effects on three Gram-positive species (S. aureus, S. epidermidis, S. pyogenes).
Meanwhile, MeOH+antibiotics combination showed significant additive synergistic effects (p

Matched MeSH terms: Gram-Positive Bacteria
Fulltext Antimicrobial activities of silver nanoparticles bio-synthesized from diatom Amphora sp.

Tevan, R., Govindaraju, Mugilan, Jayakumar, Saravanan, Govindan, Natanamurugaraj, Mohd Hasbi Ab. Rahim, Maniam, Gaanty Pragas, et al.

Journal of Engineering and Science Research, 2017;1(2):176-184.
MyJurnal

A biological method was employed to synthesize silver nanoparticles through marine diatom Amphora sp. Antimicrobial efficacy test against different pathogenic bacteria were performed through synthesized silver nanoparticles. The physio-chemical properties of synthesized silver nanoparticles were studied using analytical techniques such as UV-Vis spectrophotometer, Field Emission Scanning Electron Microscopy (FESEM), EnergyDispersive X-ray Spectroscopy (EDX) and Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Powder Diffraction (XRD). UV-Vis color intensity study and higher magnification of the Field Emission Scanning Electron Microscopy image showed the synthesized silver nanoparticles were rod shaped with a size range from 42 nm to 46 nm. The synthesized nanoparticles exhibited antibacterial activities in varying magnitudes. About 10 mg/ml of silver nanoparticles were able to inhibit the growth of gram-negative bacteria while gram-positive bacteria were resistant towards similar concentrations of silver nanoparticles.

Matched MeSH terms: Gram-Positive Bacteria
Antibacterial biocompatible arginine functionalized mono-layer graphene: No more risk of silver toxicity

Rafieerad AR, Bushroa AR, Amiri A, Kalaiselvam K, Vellasamy KM, Vadivelu J

J Hazard Mater, 2018 10 15;360:132-140.
PMID: 30099356 DOI: 10.1016/j.jhazmat.2018.07.107

Antibacterial ability is vital in biological approaches as well as functional biomaterials. Besides, cytocompatibility aspect of biologic media, tissue and organs is always concern for appropriate synthesis. From the past, metallic/oxide phases of silver (Ag) material in various macro, micro or nano configurations have been widely used for antibacterial targets. While, background of Ag toxicity within particle, film and composites is posing gradual ion release affected by molecular bounding. Recent researches conducted to control, optimize and neutralize Ag limitations finding the benefits of ideal (∼ 100%) mediation against both Gram-negative and Gram-positive bacteria. Whereas, non-degradable releases history is still a challenge and its longer accumulation may cause to disrupt biostructures and disease risk. Thus, facile development of large-area organic materials with switchable bacteria toxicity and normal cell compatibility function is interesting for concerned approaches. Here, smart positively-charged stable arginine amino acid incorporated mono layer graphene (Arg-EMGr) nanobiocomposite introduced as useful antibacterial and safe bactericidal agent competitive with Ag direct. The immunity characteristic versus Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) comparably assessed with graphene oxide (GO) and different concentrations GO-AgNPs morphology. As cell viability matter, 1,3,5,7-days vitro culture assay shown attachment proliferation and cytotoxicity due to short interaction.

Matched MeSH terms: Gram-Positive Bacteria
Synthesis of ZnO nanoparticles with chitosan as stabilizing agent and their antibacterial properties against Gram-positive and Gram-negative bacteria

Yusof NAA, Zain NM, Pauzi N

Int J Biol Macromol, 2019 Mar 01;124:1132-1136.
PMID: 30496864 DOI: 10.1016/j.ijbiomac.2018.11.228

Antibacterial activity of zinc oxide (ZnO) nanoparticles have received significant interest, particularly by the implementation of nanotechnology to synthesize particles in nanometer region. ZnO nanoparticles were successfully synthesized through microwave heating by using chitosan as a stabilizing agent and characterized by UV-vis, FTIR, XRD and FESEM-EDX. The aim of the present study is to determine the antibacterial activity of ZnO nanoparticles against Gram-positive bacterium Staphylococcus aureus (S. aureus) and Gram-negative bacterium Escherichia coli (E. coli). The antibacterial effect of ZnO nanoparticles was investigated for the inhibition zone and inactivation of cell growth. The absorption of ZnO nanoparticles was found to be around 360 nm. FTIR results showed the stretching mode of ZnO nanoparticles at 475 cm-1 of the absorption band. EDX results indicated that ZnO nanoparticles have been successfully formed with an atomic percentage of zinc and oxygen at 23.61 and 46.57% respectively. X-ray diffraction result was confirmed the single-phase formation of ZnO nanoparticles and the particle sizes were observed to be around 50 to 130 nm. The results showed that ZnO nanoparticles have displayed inhibition zone of 16 and 13 mm against S. aureus and E. coli respectively. Gram-negative bacteria seemed to be more resistant to ZnO nanoparticles than Gram-positive bacteria.

Matched MeSH terms: Gram-Positive Bacteria
Fulltext Elucidation of Antimicrobial Activity of Non-Covalently Dispersed Carbon Nanotubes

Saleemi MA, Fouladi MH, Yong PVC, Wong EH

Materials (Basel), 2020 Apr 03;13(7):6-6.
PMID: 32260216 MyJurnal DOI: 10.3390/ma13071676

Microorganisms have begun to develop resistance because of inappropriate and extensive use of antibiotics in the hospital setting. Therefore, it seems to be necessary to find a way to tackle these pathogens by developing new and effective antimicrobial agents. Carbon nanotubes (CNTs) have attracted growing attention because of their remarkable mechanical strength, electrical properties, and chemical and thermal stability for their potential applications in the field of biomedical as therapeutic and diagnostic nanotools. However, the impact of carbon nanotubes on microbial growth has not been fully investigated. The primary purpose of this research study is to investigate the antimicrobial activity of CNTs, particularly double-walled and multi-walled nanotubes on representative pathogenic strains such as Gram-positive bacteria Staphylococcus aureus, Gram-negative bacteria Pseudomonas aeruginosa, Klebsiella pneumoniae, and fungal strain Candida albicans. The dispersion ability of CNT types (double-walled and multi-walled) treated with a surfactant such as sodium dodecyl-benzenesulfonate (SDBS) and their impact on the microbial growth inhibition were also examined. A stock concentration 0.2 mg/mL of both double-walled and multi-walled CNTs was prepared homogenized by dispersing in surfactant solution by using probe sonication. UV-vis absorbance, Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM) were used for the characterization of CNTs dispersed in the surfactant solution to study the interaction between molecules of surfactant and CNTs. Later, scanning electron microscopy (SEM) was used to investigate how CNTs interact with the microbial cells. The antimicrobial activity was determined by analyzing optical density growth curves and viable cell count. This study revealed that microbial growth inhibited by non-covalently dispersed CNTs was both depend on the concentration and treatment time. In conclusion, the binding of surfactant molecules to the surface of CNTs increases its ability to disperse in aqueous solution. Non-covalent method of CNTs dispersion preserved their structure and increased microbial growth inhibition as a result. Multi-walled CNTs exhibited higher antimicrobial activity compared to double-walled CNTs against selected pathogens.

Matched MeSH terms: Gram-Positive Bacteria
Fulltext Behavior of schmutzdecke with varied filtration rates of slow sand filter to remove total coliforms

Matuzahroh N, Fitriani N, Ardiyanti PE, Kuncoro EP, Budiyanto WD, Isnadina DRM, et al.

Heliyon, 2020 Apr;6(4):e03736.
PMID: 32280804 DOI: 10.1016/j.heliyon.2020.e03736

The previous research showed that slow sand filtration (SSF) can remove the total coli by approximately 99% because of the schmutzecke layer in the filter. The presented study aimed to complete the previous research on SSF, especially on the schmuztdecke layer mechanism, to remove total coli. Total coli is a parameter of water quality standard in Indonesia, and the behavior of schmutzdecke affects the total coli removal. In the present study, the raw water from Amprong River was treated using horizontal roughing filter (HRF) and SSF. The variations in SSF rate used were 0.2 and 0.4 m/h. Total coliforms were analyzed using the most probable number test, and schmutzdecke visualization was conducted through scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDX). The best coliform concentration in water treated by the combination of HRF and SSF was 4,386 colonies per 100 mL of sample using the filtration rate of 0.2 m/h, and its removal efficiency was 99.60%. However, the quality of water treated by the combination of HRF and SSF did not meet the drinking water quality standard because the removal of total coli must be 100%. The SEM-EDX visualization results in schmutzdecke showed that the average bacteria in the schmutzdecke layer were small, white, opaque, and circular, with entire edge and flat elevation. The Gram test results showed that the schmutzdecke bacteria consisted of Gram-positive and Gram-negative bacteria with basil as the common cell form.

Matched MeSH terms: Gram-Positive Bacteria
Fulltext Bio-Mediated Synthesis of Reduced Graphene Oxide Nanoparticles from Chenopodium album: Their Antimicrobial and Anticancer Activities

Umar MF, Ahmad F, Saeed H, Usmani SA, Owais M, Rafatullah M

Nanomaterials (Basel), 2020 Jun 01;10(6).
PMID: 32492878 DOI: 10.3390/nano10061096

A novel method of preparing reduced graphene oxide (RGOX) from graphene oxide (GOX) was developed employing vegetable extract, Chenopodium album, as a reducing and stabilizing agent. Chenopodium album is a green leafy vegetable with a low shelf life, fresh leaves of this vegetable are encouraged to be used due to high water content. The previously modified 'Hummers method' has been in practice for the preparation of GOX by using precursor graphite powder. In this study, green synthesis of RGOX was functionally verified by employing FTIR and UV-visible spectroscopy, along with SEM and TEM. Our results demonstrated typical morphology of RGOX stacked in layers that appeared as silky, transparent, and rippled. The antibacterial activity was shown by analyzing minimal inhibitory concentration values, agar diffusion assay, fluorescence techniques. It showed enhanced antibacterial activity against Gram-positive and Gram-negative bacteria in comparison to GOX. It has also been shown that the synthesized compound exhibited enhanced antibiofilm activity as compared to its parent compound. The efficacy of RGOX and GOX has been demonstrated on a human breast cancer cell line, which suggested RGOX as a potential anticancer agent.

Matched MeSH terms: Gram-Positive Bacteria
Fulltext Impact of COVID-19 pandemic on multidrug resistant gram positive and gram negative pathogens: A systematic review

Abubakar U, Al-Anazi M, Alanazi Z, Rodríguez-Baño J

J Infect Public Health, 2023 Mar;16(3):320-331.
PMID: 36657243 DOI: 10.1016/j.jiph.2022.12.022

BACKGROUND: There is paucity of data describing the impact of COVID-19 pandemic on antimicrobial resistance. This review evaluated the changes in the rate of multidrug resistant gram negative and gram positive bacteria during the COVID-19 pandemic.
METHODS: A search was conducted in PubMed, Science Direct, and Google Scholar databases to identify eligible studies. Studies that reported the impact of COVID-19 pandemic on carbapenem-resistant Acinetobacter baumannii (CRAB), carbapenem-resistant Enterobacteriaceae (CRE), extended-spectrum beta-lactamase inhibitor (ESBL)-producing Enterobacteriaceae, vancomycin-resistant enterococci (VRE), methicillin-resistant Staphylococcus aureus (MRSA) and carbapenem-resistant Pseudomonas aeruginosa (CPE) were selected. Studies published in English language from the start of COVID-19 pandemic to July 2022 were considered for inclusion.
RESULTS: Thirty eligible studies were selected and most of them were from Italy (n = 8), Turkey (n = 3) and Brazil (n = 3). The results indicated changes in the rate of multidrug resistant bacteria, and the changes varied between the studies. Most studies (54.5%) reported increase in MRSA infection/colonization during the pandemic, and the increase ranged from 4.6 to 170.6%. Five studies (55.6%) reported a 6.8-65.1% increase in VRE infection/colonization during the pandemic. A 2.4-58.2% decrease in ESBL E. coli and a 1.8-13.3% reduction in ESBL Klebsiella pneumoniae was observed during the pandemic. For CRAB, most studies (58.3%) reported 1.5-621.6% increase in infection/colonization during the pandemic. Overall, studies showed increase in the rate of CRE infection/colonization during the pandemic. There was a reduction in carbapenem-resistant E. coli during COVID-19 pandemic, and an increase in carbapenem-resistant K. pneumoniae. Most studies (55.6%) showed 10.4 - 40.9% reduction in the rate of CRPA infection during the pandemic.
CONCLUSION: There is an increase in the rate of multidrug resistant gram positive and gram negative bacteria during the COVID-19 pandemic. However, the rate of ESBL-producing Enterobacteriaceae and CRPA has decrease during the pandemic. Both infection prevention and control strategies and antimicrobial stewardship should be strengthen to address the increasing rate of multidrug resistant gram positive and gram negative bacteria.

Matched MeSH terms: Gram-Positive Bacteria
Fulltext Antioxidant, Volatile Compounds; Antimicrobial, Anti-Inflammatory, and Dermatoprotective Properties of Cedrus atlantica (Endl.) Manetti Ex Carriere Essential Oil: In Vitro and In Silico Investigations

El Hachlafi N, Mrabti HN, Al-Mijalli SH, Jeddi M, Abdallah EM, Benkhaira N, et al.

Molecules, 2023 Aug 06;28(15).
PMID: 37570883 DOI: 10.3390/molecules28155913

Cedrus atlantica (Endl.) Manetti ex Carriere is an endemic tree possessing valuable health benefits which has been widely used since time immemorial in international traditional pharmacopoeia. The aim of this exploratory investigation is to determine the volatile compounds of C. atlantica essential oils (CAEOs) and to examine their in vitro antimicrobial, antioxidant, anti-inflammatory, and dermatoprotective properties. In silico simulations, including molecular docking and pharmacokinetics absorption, distribution, metabolism, excretion, and toxicity (ADMET), and drug-likeness prediction were used to reveal the processes underlying in vitro biological properties. Gas chromatography-mass spectrophotometry (GC-MS) was used for the chemical screening of CAEO. The antioxidant activity of CAEO was investigated using four in vitro complementary techniques, including ABTS and DPPH radicals scavenging activity, ferric reductive power, and inhibition of lipid peroxidation (β-carotene test). Lipoxygenase (5-LOX) inhibition and tyrosinase inhibitory assays were used for testing the anti-inflammatory and dermatoprotective properties. GC-MS analysis indicated that the main components of CAEO are β-himachalene (28.99%), α-himachalene (14.43%), and longifolene (12.2%). An in vitro antimicrobial activity of CAEO was examined against eleven strains of Gram-positive bacteria (three strains), Gram-negative bacteria (four strains), and fungi (four strains). The results demonstrated high antibacterial and antifungal activity against ten of them (>15 mm zone of inhibition) using the disc-diffusion assay. The microdilution test showed that the lowest values of MIC and MBC were recorded with the Gram-positive bacteria in particular, which ranged from 0.0625 to 0.25 % v/v for MIC and from 0.5 to 0.125 % v/v for MBC. The MIC and MFC of the fungal strains ranged from 0.5 to 4.0% (MIC) and 0.5 to 8.0% v/v (MFC). According to the MBC/MIC and MFC/MIC ratios, CAEO has bactericidal and fungicidal activity. The results of the in vitro antioxidant assays revealed that CAEO possesses remarkable antioxidant activity. The inhibitory effects on 5-LOX and tyrosinase enzymes was also significant (p < 0.05). ADMET investigation suggests that the main compounds of CAEO possess favorable pharmacokinetic properties. These findings provide scientific validation of the traditional uses of this plant and suggest its potential application as natural drugs.

Matched MeSH terms: Gram-Positive Bacteria
Elucidating the structural, catalytic, and antibacterial traits of Ficus carica and Azadirachta indica leaf extract-mediated synthesis of the Ag/CuO/rGO nanocomposite

Fayyaz Z, Farrukh MA, Ul-Hamid A, Chong KK

Microsc Res Tech, 2024 May;87(5):957-976.
PMID: 38174385 DOI: 10.1002/jemt.24487

The present exploration demonstrates the efficient, sustainable, cost-effective, and environment-friendly green approach for the synthesis of silver (Ag)-doped copper oxide (CuO) embedded with reduced graphene oxide (rGO) nanocomposite using the green one-pot method and the green deposition method. Leaf extracts of Ficus carica and Azadirachta indica were used for both methods as reducing and capping agents. The effect of methodology and plant extract was analyzed through different characterization techniques such as UV-visible spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), x-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM). The lowest band gap of 3.0 eV was observed for the Ag/CuO/rGO prepared by the green one-pot method using F. carica. The reduction of graphene oxide (GO) and the formation of metal oxide was confirmed through functional group detection using FT-IR. Calculation of thermodynamic parameters showed that all reactions involved were nonspontaneous and endothermic which shows the stability of nanocomposites. XRD studies revealed the crystallinity, phase purity and small average crystallite size of 32.67 nm. SEM images disclosed that the morphology of the nanocomposites was spherical with agglomeration and rough texture. The particle size of the nanocomposites calculated through HRTEM was found in agreement with the XRD results. The numerous properties of the synthesized nanocomposites enhanced their potential against the degradation of methylene blue, rhodamine B, and ciprofloxacin. The highest percentage degradation of Ag/CuO/rGO was found to be 97%, synthesized using the green one-pot method with F. carica against ciprofloxacin, which might be due to the lowest band gap, delayed electron-hole pair recombination, and large surface area available. The nanocomposites were also tested against the Gram-positive and Gram-negative bacteria. RESEARCH HIGHLIGHTS: Facile synthesis of Ag/CuO/rGO nanocomposite using a green one-pot method and the green deposition method. The lowest band gap of 3.0 eV was observed for nanocomposite prepared by a green one-pot method using Ficus carica. Least average crystallite size of 32.67 nm was found for nanocomposite prepared by a green one-pot method using F. carica. Highest antibacterial and catalytic activity (97%) was obtained against ciprofloxacin with nanocomposite prepared through green one-pot method using F. carica. A mechanism of green synthesis is proposed.

Matched MeSH terms: Gram-Positive Bacteria
Fulltext In Vitro Antibacterial Activity of Galls of Quercus infectoria Olivier against Oral Pathogens

Basri DF, Tan LS, Shafiei Z, Zin NM

Evid Based Complement Alternat Med, 2012;2012:632796.
PMID: 22203875 DOI: 10.1155/2012/632796

The galls of Quercus infectoria are commonly used in Malay traditional medicine to treat wound infections after childbirth. In India, they are employed traditionally as dental applications such as that in treatment of toothache and gingivitis. The aim of the present study was to evaluate the antibacterial activity of galls of Quercus infectoria Olivier against oral bacteria which are known to cause dental caries and periodontitis. Methanol and acetone extracts were screened against two Gram-positive bacteria (Streptococcus mutans ATCC 25175 and Streptococcus salivarius ATCC 13419) and two Gram-negative bacteria (Porphyromonas gingivalis ATCC 33277 and Fusobacterium nucleatum ATCC 25586). The screening test of antibacterial activity was performed using agar-well diffusion method. Subsequently, minimum inhibitory concentration (MIC) was determined by using twofold serial microdilution method at a concentration ranging between 0.01 mg/mL and 5 mg/mL. Minimum bactericidal concentration (MBC) was obtained by subculturing microtiter wells which showed no changes in colour of the indicator after incubation. Both extracts showed inhibition zones which did not differ significantly (P < 0.05) against each tested bacteria. Among all tested bacteria, S. salivarius was the most susceptible. The MIC ranges for methanol and acetone extracts were the same, between 0.16 and 0.63 mg/mL. The MBC value, for methanol and acetone extracts, was in the ranges 0.31-1.25 mg/mL and 0.31-2.50 mg/mL, respectively. Both extracts of Q. infectoria galls exhibited similar antibacterial activity against oral pathogens. Thus, the galls may be considered as effective phytotherapeutic agents for the prevention of oral pathogens.

Matched MeSH terms: Gram-Positive Bacteria
Effect of annealing temperature on antimicrobial and structural properties of bio-synthesized zinc oxide nanoparticles using flower extract of Anchusa italica

Azizi S, Mohamad R, Bahadoran A, Bayat S, Rahim RA, Ariff A, et al.

J. Photochem. Photobiol. B, Biol., 2016 Aug;161:441-9.
PMID: 27318600 DOI: 10.1016/j.jphotobiol.2016.06.007

The use of nontoxic biological compounds in the synthesis of nanomaterials is an economic and eco-friendly approach. The present work was undertaken to develop zinc oxide nanoparticles (ZnO-NPs) by a green method using simple precursor from the solution consisting of zinc acetate and the flower extract of Anchusa italica (A. italica). Effect of annealing temperature on structural and antimicrobial properties was investigated. The crystalline structure of ZnO-NPs was shown using X-ray diffraction (XRD) analysis. Transmission electron microscopy (TEM) results showed that ZnO-NPs are hexagonal in shapes with mean particle size of ~8 and ~14nm at 100°C and 200°C annealing temperatures respectively. The optical band gap was increased from 3.27eV to 3.30eV with the decreasing of the particle size. The antimicrobial activity of ZnO-NPs towards Gram positive (Bacillus megaterium and Stapphylococcus aureus) and Gram negative (Escherichia coli and Salmonella typhimurium) pathogens decreased with the increasing of the heat treating temperature. In vitro cytotoxicity studies on Vero cells, a dose dependent toxicity with non-toxic effect of concentration below 142μg/mL was shown. The results indicated that A. italica is an appropriate reaction media to prepare ZnO-NPs for cosmetic and bio-medical productions.

Matched MeSH terms: Gram-Positive Bacteria/drug effects
Antimicrobial effects of Caulerpa sertularioides extract on foodborne diarrhea-caused bacteria

Darah I, Tong WY, Nor-Afifah S, Nurul-Aili Z, Lim SH

Eur Rev Med Pharmacol Sci, 2014;18(2):171-8.
PMID: 24488904

Caulerpa (C.) sertularioides has many therapeutic uses in the practice of traditional medicine in Malaysia. Crude methanolic, diethyl ether extract, ethyl acetate extract and butanolic extract from C. sertularioides were subjected to antimicrobial screening including the three Gram-positive and three Gram-negative diarrhea-caused bacteria.

Matched MeSH terms: Gram-Positive Bacteria/drug effects*; Gram-Positive Bacterial Infections/drug therapy; Gram-Positive Bacterial Infections/microbiology
Isolation and identification of a new intracellular antimicrobial peptide produced by Paenibacillus alvei AN5

Alkotaini B, Anuar N, Kadhum AA, Sani AA

World J Microbiol Biotechnol, 2014 Apr;30(4):1377-85.
PMID: 24272828 DOI: 10.1007/s11274-013-1558-z

A wild-type, Gram-positive, rod-shaped, endospore-forming and motile bacteria has been isolated from palm oil mill sludge in Malaysia. Molecular identification using 16S rRNA gene sequence analysis indicated that the bacteria belonged to genus Paenibacillus. With 97 % similarity to P. alvei (AUG6), the isolate was designated as P. alvei AN5. An antimicrobial compound was extracted from P. alvei AN5-pelleted cells using 95 % methanol and was then lyophilized. Precipitates were re-suspended in phosphate buffered saline (PBS), producing an antimicrobial crude extract (ACE). The ACE showed antimicrobial activity against Salmonella enteritidis ATCC 13076, Escherichia coli ATCC 29522, Bacillus cereus ATCC 14579 and Lactobacillus plantarum ATCC 8014. By using SP-Sepharose cation exchange chromatography, Sephadex G-25 gel filtration and Tricine SDS-PAGE, the ACE was purified, which produced a ~2-kDa active band. SDS-PAGE and infrared (IR) spectroscopy indicated the proteinaceous nature of the antimicrobial compound in the ACE, and liquid chromatography electrospray ionization mass spectroscopy and de novo sequencing using an automatic, Q-TOF premier system detected a peptide with the amino acid sequence F-C-K-S-L-P-L-P-L-S-V-K (1,330.7789 Da). This novel peptide was designated as AN5-2. The antimicrobial peptide exhibited stability from pH 3 to 12 and maintained its activity after being heated to 90 °C. It also remained active after incubation with denaturants (urea, SDS and EDTA).

Matched MeSH terms: Gram-Positive Bacteria/drug effects
Growth, bioconversion of isoflavones and probiotic properties of parent and subsequent passages of Lactobacillus upon ultraviolet radiation

Yeo SK, Liong MT

Int J Food Sci Nutr, 2012 Nov;63(7):821-31.
PMID: 22264088 DOI: 10.3109/09637486.2011.652942

The objective of this study was to evaluate the effects of ultraviolet (UV) radiation (UVB; 90 J/m²) on growth, bioconversion of isoflavones and probiotic properties of parent and subsequent passages of L. casei FTDC 2113. UV radiation significantly enhanced (P < 0.05) the growth of parent cells in mannitol-soymilk fermented at 37°C for 24 h. This had led to an enhanced intracellular and extracellular β-glucosidase activity with a subsequent increase in bioconversion of isoflavones in mannitol-soymilk (P < 0.05). UV radiation also promoted (P < 0.05) the tolerance of parent cells towards acidic condition (pH 2 and 3) and intestinal bile salts (oxgall, taurocholic and cholic acid). In addition, parent treated cells also exhibited better (P < 0.05) adhesion ability to mucin and antimicrobial activity compared to that of the control. All these positive effects of UV radiation were only prevalent in the parent cells without inheritance by first, second and third passage of cells. Although temporary, our results suggested that UV radiation could enhance the bioactive and probiotic potentials of L. casei FTDC 2113, and thus could be applied for the production of probiotic products with enhanced bioactivity.

Matched MeSH terms: Gram-Positive Bacteria/growth & development
Fulltext Blechnum orientale Linn - a fern with potential as antioxidant, anticancer and antibacterial agent

Lai HY, Lim YY, Kim KH

BMC Complement Altern Med, 2010;10:15.
PMID: 20429956 DOI: 10.1186/1472-6882-10-15

Blechnum orientale Linn. (Blechnaceae) is used ethnomedicinally for the treatment of various skin diseases, stomach pain, urinary bladder complaints and sterilization of women. The aim of the study was to evaluate antioxidant, anticancer and antibacterial activity of five solvent fractions obtained from the methanol extract of the leaves of Blechnum orientale Linn.

Matched MeSH terms: Gram-Positive Bacteria/drug effects
Design, Synthesis, SAR Study, Antimicrobial and Anticancer Evaluation of Novel 2-Mercaptobenzimidazole Azomethine Derivatives

Tahlan S, Narasimhan B, Lim SM, Ramasamy K, Mani V, Shah SAA

Mini Rev Med Chem, 2020;20(15):1559-1571.
PMID: 30179132 DOI: 10.2174/1389557518666180903151849

BACKGROUND: Various analogues of benzimidazole are found to be biologically and therapeutically potent against several ailments. Benzimidazole when attached with heterocyclic rings has shown wide range of potential activities. So, from the above provided facts, we altered benzimidazole derivatives so that more potent antagonists could be developed. In the search for a new category of antimicrobial and anticancer agents, novel azomethine of 2-mercaptobenzimidazole derived from 3-(2- (1H-benzo[d]imidazol-2-ylthio)acetamido)benzohydrazide were synthesized.
RESULTS AND DISCUSSION: The synthesized analogues were characterized by FT-IR, 1H/13C-NMR and MS studies as well C, H, N analysis. All synthesized compounds were evaluated for in vitro antibacterial activity against Gram-positive (B. subtilis), Gram-negative (E. coli, P. aeruginosa, K. pneumoniae and S. typhi) strains and in vitro antifungal activity against C. albicans and A. niger strains by serial dilution method, the minimum inhibitory concentration (MIC) described in μM/ml. The in vitro anticancer activity of synthesized compounds was determined against human colorectal carcinoma cell line (HCT- 116) using 5-fluorouracil as standard drug.
CONCLUSION: In general, most of the synthesized derivatives exhibited significant antimicrobial and anticancer activities. Compounds 8, 10, 15, 16, 17, 20 and 22 showed significant antimicrobial activity towards tested bacterial and fungal strains and compound 26 exhibited significant anticancer activity.

Matched MeSH terms: Gram-Positive Bacteria/drug effects

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links