Displaying publications 81 - 100 of 238 in total

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  1. Genome-scale metabolic models as platforms for identification of novel genes as antimicrobial drug targets
    Mienda BS, Salihu R, Adamu A, Idris S
    Future Microbiol, 2018 03;13:455-467.
    PMID: 29469596 DOI: 10.2217/fmb-2017-0195
    The growing number of multidrug-resistant pathogenic bacteria is becoming a world leading challenge for the scientific community and for public health. However, advances in high-throughput technologies and whole-genome sequencing of bacterial pathogens make the construction of bacterial genome-scale metabolic models (GEMs) increasingly realistic. The use of GEMs as an alternative platforms will expedite identification of novel unconditionally essential genes and enzymes of target organisms with existing and forthcoming GEMs. This approach will follow the existing protocol for construction of high-quality GEMs, which could ultimately reduce the time, cost and labor-intensive processes involved in identification of novel antimicrobial drug targets in drug discovery pipelines. We discuss the current impact of existing GEMs of selected multidrug-resistant pathogenic bacteria for identification of novel antimicrobial drug targets and the challenges of closing the gap between genome-scale metabolic modeling and conventional experimental trial-and-error approaches in drug discovery pipelines.
    Matched MeSH terms: Bacteria/drug effects
  2. Screening for antibacterial agents in three species of sea cucumbers from coastal areas of Sabah
    Ridzwan BH, Kaswandi MA, Azman Y, Fuad M
    Gen. Pharmacol., 1995 Nov;26(7):1539-43.
    PMID: 8690242
    1. Three species of sea cucumbers found in the Sabah coastal areas were screened for the presence of antibacterial activity using three methods of extraction. Tests were conducted in vitro using the agar absorption method. 2. Both the lipid extract and the methanol-solvent extract from Holothuria atra, Holothuria scabra and Bohadshia argus were found to show no antibacterial activity. 3. Phosphate-buffered saline (PBS) from H. atra and B. argus, however, inhibited the growth of all gram-positive and gram-negative bacteria. 4. Comparisons were also made between extracts from the outer layer of H. atra and its inner part, and it was found that the extract from the outer layer showed less bacterial growth inhibition property. 5. The bacterial growth inhibition property of the PBS extract from H. atra, however, is dependent on the extract's concentration. Bacterial growth inhibition was apparent after 48 hr incubation.
    Matched MeSH terms: Bacteria/drug effects*
  3. Antibiotics' susceptibility patterns of bacterial isolates causing lower respiratory tract infections in ICU patients at referral hospitals in Namibia
    Simeon P, Godman B, Kalemeera F
    Hosp Pract (1995), 2021 Dec;49(5):356-363.
    PMID: 34436942 DOI: 10.1080/21548331.2021.1973825
    BACKGROUND: Lower respiratory tract infections (LRTIs) are a particular public health concern especially among sub-Saharan African countries. This is especially the case in Namibia, where LRTIs are currently the third leading cause of death, 300 deaths in children under 5 years of age. To reduce the burden of LRTIs on health systems and ensure appropriate patient management, it is critical to know the most prevalent pathogens leading to LRTIs and their susceptibility patterns in the local setting. Consequently, the objective of this study was to formulate cumulative antibiograms for Intensive Care Units (ICUs) of referral hospitals in Namibia to guide future antibiotic use.

    METHODS: A retrospective analytical cross-sectional study was conducted over 2 years. The cumulative antibiograms were constructed in accordance with current guidelines.

    RESULTS: A total of 976 first isolate cultures were obtained from ICUs of the different referral hospitals. K. pneumoniae (8.8%, 8.1%) was a predominant pathogen in Windhoek Central hospital ICU in 2017 and 2018. In Oshakati intermediate hospital ICU, Enterobacter sp. (22.2%) and P. aeruginosa (37.5%) were the common pathogens in 2017 and 2018, respectively. A. baumannii isolates were >90% susceptibility to colistin, carbapenems, and tigecycline in 2017. In 2017, K. pneumoniae isolates were more susceptible to carbapenems (94% and 93.8% among isolates), amikacin (89.3%), and tigecycline (88.7%). In 2018, K. pneumoniae isolates were 100% susceptible amikacin, colistin, and carbapenems. S. maltophilia isolates were more than 80% susceptible to all the tested antibiotics. S. aureus isolates were 100% susceptible to linezolid, rifampicin, teicoplanin, and vancomycin in 2017 and in 2018. Its susceptibility to these antibiotics did not change.

    CONCLUSION: The susceptibility patterns of the common isolated gram-negative pathogens were highly variable. Meropenem in combination with gentamicin is now the recommended antibiotic combination for empiric therapy for patients with LRTIs in Windhoek Central Hospital ICU.

    Matched MeSH terms: Gram-Negative Bacteria/drug effects*
  4. Fulltext Autoclave-assisted synthesis of AgNPs in Z. officinale extract and assessment of their cytotoxicity, antibacterial and antioxidant activities
    Kalantari K, Afifi AM, Moniri M, Moghaddam AB, Kalantari A, Izadiyan Z
    IET Nanobiotechnol, 2019 May;13(3):262-268.
    PMID: 31053688 DOI: 10.1049/iet-nbt.2018.5066
    In this study, the authors synthesised silver nanoparticles (AgNPs) using autoclave as a simple, unique and eco-friendly approach. The effect of Zingiber officinale extract was evaluated as a reducing and stabiliser agent. According to transmission electron microscopy results, the AgNPs were in the spherical shape with a particle size of ∼17 nm. The biomedical properties of AgNPs as antibacterial agents and free radical scavenging activity were estimated. Synthesised AgNPs showed significant 1,1-diphenyl-2-picryl-hydrazyl free radical scavenging. Strong bactericidal activity was shown by the AgNPs on Gram-positive and Gram-negative bacteria. A maximum inhibition zone of ∼14 mm was obtained for epidermidis at a concentration of 60 μg/ml for sample fabricated at 24 h. The AgNPs also showed a significant cytotoxic effect against MCF-7 breast cancer cell lines with an half maximal inhibitory concentration value of 62 μg/ml in 24 h by the MTT assay. It could be concluded that Z. officinale extract can be used effectively in the production of potential antioxidant and antimicrobial AgNPs for commercial application.
    Matched MeSH terms: Gram-Negative Bacteria/drug effects; Gram-Positive Bacteria/drug effects
  5. Fulltext Surfactant-mediated synthesis of polyhydroxybutyrate (PHB) nanoparticles for sustained drug delivery
    Pachiyappan S, Shanmuganatham Selvanantham D, Kuppa SS, Chandrasekaran S, Samrot AV
    IET Nanobiotechnol, 2019 Jun;13(4):416-427.
    PMID: 31171747 DOI: 10.1049/iet-nbt.2018.5053
    In this study, polyhydroxybutyrate (PHB) nanoparticles were synthesised following nanoprecipitation method having different solvents and surfactant (Tween 80) concentrations. In this study, PHB nanoparticles were encapsulated with curcumin and subjected for sustained curcumin delivery. Both the curcumin loaded and unloaded PHB nanoparticles were characterised using FTIR, SEM, and AFM. Sizes of the particles were found to be between 60 and 300 nm. The drug encapsulation efficiency and in vitro drug release of the nanoparticles were analysed. Antibacterial activity and anticancer activity were also evaluated. The LC50 values of most of the nanoparticles were found to be between 10 and 20 µg/100 µl, anticancer activity of curcumin loaded PHB nanoparticles were further confirmed by AO/PI staining and mitochondrial depolarisation assay.
    Matched MeSH terms: Bacteria/drug effects
  6. Bacterial dynamics associated with algal antibacterial substances during post harvest desiccation process of Sargassum stolonifolium Phang et Yoshida
    Vairappan CS
    Indian J Exp Biol, 2003 Aug;41(8):837-45.
    PMID: 15248481
    Brown algae of genus Sargassum are known to produce relatively higher amount of alginic acid. Optimal extraction of this algalcolloid for local consumption requires in-depth studies on post-harvest treatment of the algal fronds. Present investigation endeavors to establish the dynamics and inter-relationship of moisture content and bacteria found on the surface of the alga and alginic acid content during post-harvest desiccation of Sargassum stolonifolium Phang et Yoshida. Harvested fronds were subjected to desiccation for 31 days and bacterial dynamics were monitored with relation to moisture content and water activity index (a(w)). There was 85% decrease in moisture content, however, a(w) showed a more gradual decrease. Total bacterial count increased during the first week and attained maximal value on day 7. Thereafter, a drastic decrease was seen until day 14, followed by a gradual decline. Six species of bacteria were isolated and identified, i.e. Azomonas punctata, Azomonas sp., Escherichia coli, Micrococcus sp., Proteus vulgaris and Vibrio alginolyticus. Calculated ratios for increase in alginic acid content and decrease in moisture content were almost the same throughout the desiccation process, implying that extracellular alginase-producing bacteria did not use the alginic acid produced by the algae as its carbon source. It became apparent that drastic decrease in bacterial count after day 7 could not be attributed to salinity, moisture content, a(w) or lack of carbon source for the bacteria. The possible exposure of these bacteria to algal cell sap which is formed due to the rupture of algal cells was seen as the most likely reason for the drop in bacterial population. Scanning electron microscope (SEM) micrograph taken on day 10 of desiccation showed the presence of cracks and localities where bacteria were exposed to algal cell sap. In vitro antibacterial tests were carried out to verify the effect of algal extracts. Separation and purification of crude algal extracts via bioassay guided separation methodology revealed the identity of active compounds (i.e. gylcolipids and free fatty acids) involved in this inherently available antibacterial defense mechanism during algal desiccation.
    Matched MeSH terms: Gram-Negative Bacteria/drug effects; Gram-Positive Bacteria/drug effects
  7. Fulltext Bacterial and fungal keratitis in Upper Egypt: in vitro screening of enzymes, toxins and antifungal activity
    Gharamah AA, Moharram AM, Ismail MA, Al-Hussaini AK
    Indian J Ophthalmol, 2014 Feb;62(2):196-203.
    PMID: 24008795 DOI: 10.4103/0301-4738.116463
    This work was conducted to study the ability of bacterial and fungal isolates from keratitis cases in Upper Egypt to produce enzymes, toxins, and to test the isolated fungal species sensitivity to some therapeutic agents.
    Matched MeSH terms: Bacteria/drug effects
  8. Fulltext Preliminary comparative analysis of antibacterial effects of activated and non-activated of expired platelet concentrate by disc diffusion method
    Zabidi MA, Yusoff NM, Kader ZS
    Indian J Pathol Microbiol, 2012 Jan-Mar;55(1):47-51.
    PMID: 22499300 DOI: 10.4103/0377-4929.94855
    Platelets release more than 30 cytokines to provide primary hemostatic function. In addition, platelets are also known to release antimicrobial peptides upon activation by thrombin.
    Matched MeSH terms: Gram-Negative Bacteria/drug effects*; Gram-Positive Bacteria/drug effects*
  9. Therapeutic challenges in the era of antibiotic resistance
    Lee C
    Int J Antimicrob Agents, 2008 Dec;32 Suppl 4:S197-9.
    PMID: 19134519 DOI: 10.1016/S0924-8579(09)70002-0
    Multidrug microbial resistance poses major challenges to the management of infection, particularly with the paucity of new drugs with activity against these bacteria. Since the turn of this century a few new antibiotics have been licensed, including linezolid, daptomycin and tigecycline. This supplement reports data presented at the 13th International Congress of Infectious Diseases held in Kuala Lumpur in June 2008. Dr R. Isturiz reviews the data on global resistance trends and the potential impact on empirical therapy; Dr J.-H. Song reviews new agents on the antimicrobial horizon; and the final paper in the supplement, by Dr L.R. Peterson, reviews the role of tigecycline in the management of complicated intra-abdominal and skin and soft tissue infections.
    Matched MeSH terms: Bacteria/drug effects*
  10. Epidemiology and trends in the antibiotic susceptibilities of Gram-negative bacilli isolated from patients with intra-abdominal infections in the Asia-Pacific region, 2010-2013
    Chang YT, Coombs G, Ling T, Balaji V, Rodrigues C, Mikamo H, et al.
    Int J Antimicrob Agents, 2017 Jun;49(6):734-739.
    PMID: 28435019 DOI: 10.1016/j.ijantimicag.2017.01.030
    This study was conducted to investigate the epidemiology and antimicrobial susceptibility patterns of Gram-negative bacilli (GNB) isolated from intra-abdominal infections (IAIs) in the Asia-Pacific region (APR) from 2010-2013. A total of 17 350 isolates were collected from 54 centres in 13 countries in the APR. The three most commonly isolated GNB were Escherichia coli (46.1%), Klebsiella pneumoniae (19.3%) and Pseudomonas aeruginosa (9.8%). Overall, the rates of extended-spectrum β-lactamase (ESBL)-producing E. coli and K. pneumoniae were 38.2% and 24.3%, respectively, and they were highest in China (66.6% and 38.7%, respectively), Thailand (49.8% and 36.5%, respectively) and Vietnam (47.9% and 30.4%, respectively). During 2010-2013, the rates of ESBL-producing E. coli and K. pneumoniae isolates causing community-associated (CA) IAIs (collected <48 h after admission) were 26.0% and 13.5%, respectively, and those causing hospital-associated (HA) IAIs were 48.0% and 30.6%, respectively. Amikacin, ertapenem and imipenem were the most effective agents against ESBL-producing isolates. Piperacillin/tazobactam displayed good in vitro activity (91.4%) against CA ESBL-producing E. coli. For other commonly isolated Enterobacteriaceae, fluoroquinolones, cefepime and carbapenems exhibited better in vitro activities than third-generation cephalosporins. Amikacin possessed high in vitro activity against all GNB isolates (>80%) causing IAIs, except for Acinetobacter calcoaceticus-baumannii (ACB) complex (30.9% for HA-IAI isolates). All of the antimicrobial agents tested exhibited <45% in vitro activity against ACB complex. Antimicrobial resistance is a persistent threat in the APR and continuous monitoring of evolutionary trends in the susceptibility patterns of GNB causing IAIs in this region is mandatory.
    Matched MeSH terms: Gram-Negative Bacteria/drug effects*
  11. Infections by multidrug-resistant Gram-negative Bacteria: What's new in our arsenal and what's in the pipeline?
    Koulenti D, Song A, Ellingboe A, Abdul-Aziz MH, Harris P, Gavey E, et al.
    Int J Antimicrob Agents, 2019 Mar;53(3):211-224.
    PMID: 30394301 DOI: 10.1016/j.ijantimicag.2018.10.011
    The spread of multidrug-resistant bacteria is an ever-growing concern, particularly among Gram-negative bacteria because of their intrinsic resistance and how quickly they acquire and spread new resistance mechanisms. Treating infections caused by Gram-negative bacteria is a challenge for medical practitioners and increases patient mortality and cost of care globally. This vulnerability, along with strategies to tackle antimicrobial resistance development, prompts the development of new antibiotic agents and exploration of alternative treatment options. This article summarises the new antibiotics that have recently been approved for Gram-negative bacterial infections, looks down the pipeline at promising agents currently in phase I, II, or III clinical trials, and introduces new alternative avenues that show potential in combating multidrug-resistant Gram-negative bacteria.
    Matched MeSH terms: Gram-Negative Bacteria/drug effects*
  12. The state of ESKAPE in Malaysia
    McNeil HC, Lean SS, Lim V, Clarke SC
    Int J Antimicrob Agents, 2016 Nov;48(5):578-579.
    PMID: 27742200 DOI: 10.1016/j.ijantimicag.2016.08.011
    Matched MeSH terms: Gram-Negative Bacteria/drug effects*; Gram-Positive Bacteria/drug effects*
  13. Hydrogel beads bio-nanocomposite based on Kappa-Carrageenan and green synthesized silver nanoparticles for biomedical applications
    Azizi S, Mohamad R, Abdul Rahim R, Mohammadinejad R, Bin Ariff A
    Int J Biol Macromol, 2017 Nov;104(Pt A):423-431.
    PMID: 28591593 DOI: 10.1016/j.ijbiomac.2017.06.010
    This paper describes the fabrication and characterization of bio-nanocomposite hydrogel beads based on Kappa-Carrageenan (κ-Carrageenan) and bio-synthesized silver nanoparticles (Ag-NPs). The silver nanoparticles were prepared in aqueous Citrullus colocynthis seed extract as both reducing and capping agent. Cross-linked κ-Carrageenan/Ag-NPs hydrogel beads were prepared using potassium chloride as the cross-linker. The hydrogel beads were characterized using XRD and FESEM. Moreover, swelling property of the hydrogel beads was investigated. The Ag release profile of the hydrogels was obtained by fitting the experimental data to power law equation. The direct visualization of the green synthesized Ag-NPs using TEM shows particle size in the range of 23±2nm. The bio-nanocomposite hydrogels showed lesser swelling behavior in comparison with pure κ-Carrageenan hydrogel. Regardless the slow Ag release, κ-Carrageenan/Ag-NPs presented good antibacterial activities against Staphylococcus aureus, Methicilin Resistant Staphylococcus aurous, Peseudomonas aeruginosa and Escherichia coli with maximum zones of inhibition 11±2mm. Cytotoxicity study showed that the bio-nanocomposite hydrogels with non-toxic effect of concentration below 1000μg/mL have great pharmacological potential and a suitable level of safety for use in the biological systems.
    Matched MeSH terms: Bacteria/drug effects
  14. Fulltext Bacteremia in patients with febrile neutropenia after chemotherapy at a university medical center in Malaysia
    Baskaran ND, Gan GG, Kamarulzaman A, Sam IC
    Int J Infect Dis, 2007 Nov;11(6):513-7.
    PMID: 17459753
    OBJECTIVES: This study was initiated to determine the local profile of blood culture isolates and antibiotic sensitivities in febrile neutropenic patients following chemotherapy, and to establish if any modifications to treatment guidelines are necessary.
    DESIGN: A total of 116 episodes of febrile neutropenia admitted to the adult hematology ward at a university medical center in Malaysia were studied retrospectively from January 2004 to January 2005.
    RESULTS: The study showed 43.1% of febrile neutropenic episodes had established bacteremia. Gram-negative bacteria accounted for 60.3% of isolates. Sensitivities of Gram-negative bacteria to the antibiotics recommended in the Infectious Diseases Society of America (IDSA) guidelines were 86.1-97.2%. Coagulase-negative staphylococci were the most common Gram-positive organisms isolated (23.3%). The majority of these were methicillin-resistant.
    CONCLUSIONS: Carbapenem monotherapy, as recommended in the 2002 IDSA guidelines, is effective treatment for the infections most often encountered at our center. Combination therapy with an aminoglycoside should be considered when using ceftazidime, cefepime or piperacillin-tazobactam, particularly in high-risk patients. Vancomycin should be used if a Gram-positive organism is suspected or isolated.
    Matched MeSH terms: Bacteria/drug effects
  15. Fulltext Flavonoid analyses and antimicrobial activity of various parts of Phaleria macrocarpa (Scheff.) Boerl fruit
    Hendra R, Ahmad S, Sukari A, Shukor MY, Oskoueian E
    Int J Mol Sci, 2011;12(6):3422-31.
    PMID: 21747685 DOI: 10.3390/ijms12063422
    Phaleria macrocarpa (Scheff.) Boerl (Thymelaceae) is commonly known as 'Crown of God', 'Mahkota Dewa', and 'Pau'. It originates from Papua Island, Indonesia and it grows in tropical areas. Empirically, it is potent in treating the hypertensive, diabetic, cancer and diuretic patients. It has a long history of ethnopharmacological usage, and the lack of information about its biological activities led us to investigate the possible biological activities by characterisation of flavonoids and antimicrobial activity of various part of P. macrocarpa against pathogenic bacteria and fungi. The results showed that kaempferol, myricetin, naringin, and rutin were the major flavonoids present in the pericarp while naringin and quercetin were found in the mesocarp and seed. Furthermore, the antibacterial activity of different parts of P. macrocarpa fruit showed a weak ability to moderate antibacterial activity against pathogenic tested bacteria (inhibition range: 0.93-2.17 cm) at concentration of 0.3 mg/disc. The anti fungi activity was only found in seed extract against Aspergillus niger (1.87 cm) at concentration of 0.3 mg/well. From the results obtained, P. macrocarpa fruit could be considered as a natural antimicrobial source due to the presence of flavonoid compounds.
    Matched MeSH terms: Gram-Negative Bacteria/drug effects; Gram-Positive Bacteria/drug effects
  16. Fulltext Synthesis, PASS-Predication and in Vitro Antimicrobial Activity of Benzyl 4-O-benzoyl-α-l-rhamnopyranoside Derivatives
    Matin MM, Nath AR, Saad O, Bhuiyan MM, Kadir FA, Abd Hamid SB, et al.
    Int J Mol Sci, 2016 Aug 27;17(9).
    PMID: 27618893 DOI: 10.3390/ijms17091412
    Benzyl α-l-rhamnopyranoside 4, obtained by both conventional and microwave assisted glycosidation techniques, was subjected to 2,3-O-isopropylidene protection to yield compound 5 which on benzoylation and subsequent deprotection of isopropylidene group gave the desired 4-O-benzoylrhamnopyranoside 7 in reasonable yield. Di-O-acetyl derivative of benzoate 7 was prepared to get newer rhamnopyranoside. The structure activity relationship (SAR) of the designed compounds was performed along with the prediction of activity spectra for substances (PASS) training set. Experimental studies based on antimicrobial activities verified the predictions obtained by the PASS software. Protected rhamnopyranosides 5 and 6 exhibited slight distortion from regular ¹C₄ conformation, probably due to the fusion of pyranose and isopropylidene ring. Synthesized rhamnopyranosides 4-8 were employed as test chemicals for in vitro antimicrobial evaluation against eight human pathogenic bacteria and two fungi. Antimicrobial and SAR study showed that the rhamnopyranosides were prone against fungal organisms as compared to that of the bacterial pathogens. Interestingly, PASS prediction of the rhamnopyranoside derivatives 4-8 were 0.49 < Pa < 0.60 (where Pa is probability 'to be active') as antibacterial and 0.65 < Pa < 0.73 as antifungal activities, which showed significant agreement with experimental data, suggesting rhamnopyranoside derivatives 4-8 were more active against pathogenic fungi as compared to human pathogenic bacteria thus, there is a more than 50% chance that the rhamnopyranoside derivative structures 4-8 have not been reported with antimicrobial activity, making it a possible valuable lead compound.
    Matched MeSH terms: Bacteria/drug effects
  17. Fulltext Antimicrobial Polymers: The Potential Replacement of Existing Antibiotics?
    Kamaruzzaman NF, Tan LP, Hamdan RH, Choong SS, Wong WK, Gibson AJ, et al.
    Int J Mol Sci, 2019 Jun 04;20(11).
    PMID: 31167476 DOI: 10.3390/ijms20112747
    Antimicrobial resistance is now considered a major global challenge; compromising medical advancements and our ability to treat infectious disease. Increased antimicrobial resistance has resulted in increased morbidity and mortality due to infectious diseases worldwide. The lack of discovery of novel compounds from natural products or new classes of antimicrobials, encouraged us to recycle discontinued antimicrobials that were previously removed from routine use due to their toxicity, e.g., colistin. Since the discovery of new classes of compounds is extremely expensive and has very little success, one strategy to overcome this issue could be the application of synthetic compounds that possess antimicrobial activities. Polymers with innate antimicrobial properties or that have the ability to be conjugated with other antimicrobial compounds create the possibility for replacement of antimicrobials either for the direct application as medicine or implanted on medical devices to control infection. Here, we provide the latest update on research related to antimicrobial polymers in the context of ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) pathogens. We summarise polymer subgroups: compounds containing natural peptides, halogens, phosphor and sulfo derivatives and phenol and benzoic derivatives, organometalic polymers, metal nanoparticles incorporated into polymeric carriers, dendrimers and polymer-based guanidine. We intend to enhance understanding in the field and promote further work on the development of polymer based antimicrobial compounds.
    Matched MeSH terms: Bacteria/drug effects
  18. Fulltext Bioactive compounds and biological activities of Jatropha curcas L. kernel meal extract
    Oskoueian E, Abdullah N, Ahmad S, Saad WZ, Omar AR, Ho YW
    Int J Mol Sci, 2011;12(9):5955-70.
    PMID: 22016638 DOI: 10.3390/ijms12095955
    Defatted Jatropha curcas L. (J. curcas) seed kernels contained a high percentage of crude protein (61.8%) and relatively little acid detergent fiber (4.8%) and neutral detergent fiber (9.7%). Spectrophotometric analysis of the methanolic extract showed the presence of phenolics, flavonoids and saponins with values of 3.9, 0.4 and 19.0 mg/g DM, respectively. High performance liquid chromatography (HPLC) analyses showed the presence of gallic acid and pyrogallol (phenolics), rutin and myricetin (flavonoids) and daidzein (isoflavonoid). The amount of phorbol esters in the methanolic extract estimated by HPLC was 3.0 ± 0.1 mg/g DM. Other metabolites detected by GC-MS include: 2-(hydroxymethyl)-2 nitro-1,3-propanediol, β-sitosterol, 2-furancarboxaldehyde, 5-(hydroxymethy) and acetic acid in the methanolic extract; 2-furancarboxaldehyde, 5-(hydroxymethy), acetic acid and furfural (2-furancarboxaldehyde) in the hot water extract. Methanolic and hot water extracts of kernel meal showed antimicrobial activity against both Gram positive and Gram negative pathogenic bacteria (inhibition range: 0-1.63 cm) at the concentrations of 1 and 1.5 mg/disc. Methanolic extract exhibited antioxidant activities that are higher than hot water extract and comparable to β-carotene. The extracts tended to scavenge the free radicals in the reduction of ferric ion (Fe(3+)) to ferrous ion (Fe(2+)). Cytotoxicity assay results indicated the potential of methanolic extract as a source of anticancer therapeutic agents toward breast cancer cells.
    Matched MeSH terms: Gram-Negative Bacteria/drug effects; Gram-Positive Bacteria/drug effects
  19. Fulltext Synthesis, characterization, and antimicrobial activity of an ampicillin-conjugated magnetic nanoantibiotic for medical applications
    Hussein-Al-Ali SH, El Zowalaty ME, Hussein MZ, Geilich BM, Webster TJ
    Int J Nanomedicine, 2014;9:3801-14.
    PMID: 25143729 DOI: 10.2147/IJN.S61143
    Because of their magnetic properties, magnetic nanoparticles (MNPs) have numerous diverse biomedical applications. In addition, because of their ability to penetrate bacteria and biofilms, nanoantimicrobial agents have become increasingly popular for the control of infectious diseases. Here, MNPs were prepared through an iron salt coprecipitation method in an alkaline medium, followed by a chitosan coating step (CS-coated MNPs); finally, the MNPs were loaded with ampicillin (amp) to form an amp-CS-MNP nanocomposite. Both the MNPs and amp-CS-MNPs were subsequently characterized and evaluated for their antibacterial activity. X-ray diffraction results showed that the MNPs and nanocomposites were composed of pure magnetite. Fourier transform infrared spectra and thermogravimetric data for the MNPs, CS-coated MNPs, and amp-CS-MNP nanocomposite were compared, which confirmed the CS coating on the MNPs and the amp-loaded nanocomposite. Magnetization curves showed that both the MNPs and the amp-CS-MNP nanocomposites were superparamagnetic, with saturation magnetizations at 80.1 and 26.6 emu g(-1), respectively. Amp was loaded at 8.3%. Drug release was also studied, and the total release equilibrium for amp from the amp-CS-MNPs was 100% over 400 minutes. In addition, the antimicrobial activity of the amp-CS-MNP nanocomposite was determined using agar diffusion and growth inhibition assays against Gram-positive bacteria and Gram-negative bacteria, as well as Candida albicans. The minimum inhibitory concentration of the amp-CS-MNP nanocomposite was determined against bacteria including Mycobacterium tuberculosis. The synthesized nanocomposites exhibited antibacterial and antifungal properties, as well as antimycobacterial effects. Thus, this study introduces a novel β-lactam antibacterial-based nanocomposite that can decrease fungus activity on demand for numerous medical applications.
    Matched MeSH terms: Bacteria/drug effects
  20. Fulltext Synthesis, characterization, and antimicrobial properties of copper nanoparticles
    Usman MS, El Zowalaty ME, Shameli K, Zainuddin N, Salama M, Ibrahim NA
    Int J Nanomedicine, 2013;8:4467-79.
    PMID: 24293998 DOI: 10.2147/IJN.S50837
    Copper nanoparticle synthesis has been gaining attention due to its availability. However, factors such as agglomeration and rapid oxidation have made it a difficult research area. In the present work, pure copper nanoparticles were prepared in the presence of a chitosan stabilizer through chemical means. The purity of the nanoparticles was authenticated using different characterization techniques, including ultraviolet visible spectroscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and field emission scanning electron microscopy. The antibacterial as well as antifungal activity of the nanoparticles were investigated using several microorganisms of interest, including methicillin-resistant Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Salmonella choleraesuis, and Candida albicans. The effect of a chitosan medium on growth of the microorganism was studied, and this was found to influence growth rate. The size of the copper nanoparticles obtained was in the range of 2-350 nm, depending on the concentration of the chitosan stabilizer.
    Matched MeSH terms: Bacteria/drug effects*
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