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Journal ArticleDOI: 10.1080/22311866.2014.957097

Susceptibility Testing of Methicillin Resistant Staphylococcus aureus (MRSA) and Biological Role of Silver Nanoparticles of Honey Against MRSA

02 Nov 2014-Journal of biologically active products from nature (Taylor & Francis)-Vol. 4, pp 332-342
Abstract: Methicillin resistant Staphylococcus aureus (MRSA) is a very common nosocomial pathogen and in this study the occurrence of MRSA infections and their susceptibility pattern were tested. A total of 50 MRSA strains were collected from pus samples. All isolates were found to be sensitive to vancomycin and imipenem. Further minimum inhibitory concentration (MIC) of vancomycin was performed by agar dilution method, 24 % of the strains were inhibited at a concentration of 4 µg/ml and other 10 % at 8 µg/ml. It was observed that none of the isolates could tolerate 16 µg/ml and E-test also showed that 64 % of them were sensitive and 36 % were intermediately resistant. All the strains were tested for slime production by Congo red agar method and biofilm formation by microtitre plate method. Out of the total strains tested 58 % exhibited positive result for slime production and 70 % were biofilm positive. All the MRSA strains were tested for MIC with two types of honey which gave MIC of 30 %. Sarvodaya honey and Tulsi honey were chosen for the study. Further silver nanoparticles were synthesized using honey and the antimicrobial activities against the pathogens were checked. The study showed that honey has antibacterial activity against test organisms and may form an alternative therapy against certain bacteria. more


Journal ArticleDOI: 10.1515/NTREV-2016-0049
01 Dec 2016-Nano Reviews
Abstract: Abstract Nanotechnology has remained relevant as a multifacet discipline, which cuts across different areas of science and technology. Several successful attempts had been documented regarding the involvement of biological materials in the green synthesis of various metal nanoparticles (MeNPs) because of their eco-friendliness, cost-effectiveness, safe handling, and ultimately less toxicity as opposed to the physical and chemical methods with their concomitant problems. Biological agents, including bacteria, fungi, algae, enzymes, plants, and their extracts, have been implicated in most cases by several authors. Moreover, nanotechnology in recent times has also made an inroad for animal species, specifically arthropods and metabolites thereof to be used as excellent candidates for the green synthesis of MeNPs. The increasing literature on the use of metabolites of arthropods for the green synthesis of nanoparticles has necessitated the need to document a review on their relevance in nanobiotechnology. The review, which represents the first of its kind, seeks to underscore the importance of arthropods in the multidisciplinary subject of nanoscience and nanotechnology. more

73 Citations

Journal ArticleDOI: 10.1002/BTPR.2829
Abstract: The search for biocompatible nanoparticles with vast applicability has impacted on exploration of various biomaterials for the synthesis of mono and bimetallic nanoparticles. Xylanase is widely regarded as an industrially important enzyme but its potentials in nanotechnological applications are yet to be fully explored. The current study investigates the exploit of xylanases of Aspergillus niger L3 (NE) and Trichoderma longibrachiatum L2 (TE) produced through valorization of corn-cob, to synthesize silver-gold alloy nanoparticles (Ag-AuNPs). Characterization of the Ag-AuNPs involved UV-vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy and transmission electron microscopy, while their prospective use as antimicrobial, antioxidant, catalytic, anticoagulant, and thrombolytic agents were studied. The biosynthesized Ag-AuNPs were ruby red and light purple with surface plasmon resonance at 520 and 534 nm for NEAg-AuNPs and TEAg-AuNPs, respectively; while FTIR showed that protein molecules capped and stabilized the nanoparticles. The Ag-AuNPs were anisotropic with spherical, oval, and irregular shapes having sizes ranging from 6.98 to 52.51 nm. The nanoparticles appreciably inhibited the growth of tested clinical bacteria (23.40-90.70%) and fungi (70.10-89.05%), and also scavenged 2,2-diphenyl-1-picrylhydrazyl (48.51-53.79%) and hydrogen peroxide (80.5-95.50%). Furthermore, the Ag-AuNPs degraded malachite green (91.39%) and methylene blue (47.10%). Moreover, the Ag-AuNPs displayed outstanding anticoagulant and thrombolytic activities using human blood. This study further emphasizes the significance of xylanases in nanobiotechnology as it has established the potential of xylanases to synthesize Ag-AuNPs, which is being reported for the first time. more

45 Citations

Book ChapterDOI: 10.1007/978-3-319-76090-2_8
01 Jan 2018-
Abstract: Nanotechnology has evolved as a novel multidisciplinary concept of the twenty-first century, abridging gaps in materials science, engineering, life sciences and medicine, with tremendous applications in diverse areas of human endeavours. Nanoparticles, which form critical components of nanoscience and nanotechnology, have also played prominent roles in extending the frontiers of applications of the emerging discipline. The metallic nanoparticles, owing to their unique optical, surface, chemical, biological, catalytic, electronic, and resonance properties have formed an epicentre of research in recent times, with major focus on synthesis and novel applications. A new line of application that has emerged is in the delivery of quality healthcare, leading to the offshoot of a sub-discipline, nanomedicine. A major health problem confronting man is the blood coagulation disorder, which often leads to cardiovascular diseases, with the attendant high mortality worldwide. The use of conventional drugs in the treatment blood coagulation has been plagued with problems of high cost, short-lived action and adverse severe reactions. Hence, there is need to search for newer treatment regimes with improved outcomes, of which nanotechnology holds a promising future. In this review, we focus on the emerging applications of metallic nanoparticles in the management of blood coagulation disorders; notably in the prevention of clot formation, dissolution of blood clots, and in the combined role of therapeutic and diagnostic agents. The review presents a comprehensive overview on blood coagulation disorders, synthesis and applications of metallic nanoparticles, and the novel management of blood coagulation disorders using nanoplatform deliveries. Emphasis has been placed on the prospects of the use of metallic nanoparticles such as silver, gold and silver-gold alloy nanoparticles as anticoagulant, thrombolytic and theranostic agents, with evidences of excellent performances in the prevention of blood clot formation, dissolution of blood clots, and enhanced imaging of thrombus (blood clot) in vivo. The increasing appraisals of these nanoplatforms, potent action, improved biocompatibility cum absence of complications of excessive bleeding are good indicators of potential future integration in the clinical management of blood coagulation disorders. However, diligent studies are needed to be conducted to establish the long-term safety of applications of these nanomedical materials. The compendium seeks to bring to the fore, the continued relevance of nanotechnology in the twenty-first century, and its potential dynamic integration into medicare programmes. more

33 Citations

Open accessJournal ArticleDOI: 10.1088/1757-899X/805/1/012044
01 Mar 2020-

3 Citations

Book ChapterDOI: 10.1007/978-981-33-4777-9_9
E. A. Adebayo, M. A. Azeez, M. B. Alao1, M. A. Oke1  +1 moreInstitutions (2)
01 Jan 2021-
Abstract: In nanobiotechnological research, mushrooms are of great interest. The high nutritional and medicinal value, phytochemicals, polysaccharide, protein, enzymes, glucan and other bioactive compounds present in mushrooms have made them sources of good precursors for nanoparticles synthesis. Mushrooms-mediated nanoparticles biosynthesis is an interesting research field, as these macrofungi act as eco-friendly biofactories that secrete enzymes and phytochemicals essential for metal ions reduction to zerovalent or nano-form. Nanotechnology provides a unique pathway of technological deliveries through biological entities’ revolution and exploration as found in mushrooms. The synthesis of nanomaterials physically or chemically raises concerns regarding toxic by-products. Biological synthesis of nanoparticles is now of great interest in the world as it provides safer environmental-friendly technique and biocompatible applications in contrast to the conventional methods of physical and chemical strategies. Several species of mushrooms such as Agaricus, Calocybe, Pleurotus, Ganoderma, Lentinula and Volvariella among others have been used for metallic nanoparticles synthesis and their antimicrobial, antioxidant, antitumor, anti-inflammatory and other medicinal importance have been explored. Synthesized nanoparticles from mushroom enzymes such as α-amylase, laccase and other metabolites like polysaccharide and glucan may have their importance in bioremediation, bioleaching, biocatalysis, water purification and other industrial processes. Mushrooms are favoured in nanobiotechnology due to their relatively safe nature and ease of production, high stability and longer shelf life, enhanced biological activities of metabolites and enzymes coupled with ease of extraction. They exhibit higher stability, longer shelf life and enhanced biological activities. On this note, the concept and development of mushroom nanotechnology will be directed towards utility of mushrooms in biosynthesis of nanoparticles. Furthermore, the importance of mushroom-mediated nanoparticles and future role in addressing medical and industrial problems will also be explored. more

Topics: Agaricus (53%), Pleurotus (52%)

2 Citations


Journal ArticleDOI: 10.1097/01.MD.0000091184.93122.09
01 Sep 2003-Medicine
Abstract: Staphylococcus aureus bacteremia is associated with substantial morbidity. Recurrence is common, but incidence and risk factors for recurrence are uncertain. The emergence of methicillin resistance and the ease of administering vancomycin, especially in patients who have renal insufficiency, have led to reliance on this drug with the assumption that it is as effective as beta-lactam antibiotics, an assumption that remains open to debate. We initiated a multicenter, prospective observational study in 6 university hospitals and enrolled 505 consecutive patients with S. aureus bacteremia. All patients were monitored for 6 months and patients with endocarditis were followed for 3 years. Recurrence was defined as return of S. aureus bacteremia after documentation of negative blood cultures and/or clinical improvement after completing a course of antistaphylococcal antibiotic therapy. All blood isolates taken from patients with recurrent bacteremia underwent pulsed-field gel electrophoresis testing. Recurrence was subclassified as reinfection (different pulsed-field gel electrophoresis patterns) or relapse (same pulsed-field gel electrophoresis pattern).Forty-two patients experienced 56 episodes of recurrence (79% were relapses and 21% were reinfection). Relapse occurred earlier than reinfection (median, 36 versus 99 d, p < 0.06). Risk factors for relapse of S. aureus bacteremia included valvular heart disease, cirrhosis of the liver, and deep-seated infection (including endocarditis). Nafcillin was superior to vancomycin in preventing bacteriologic failure (persistent bacteremia or relapse) for methicillin-susceptible S. aureus (MSSA) bacteremia. Failure to remove infected intravascular devices/catheters and vancomycin therapy were common factors in patients experiencing multiple (greater than 2) relapses. However, by multivariate analysis, only endocarditis and therapy with vancomycin (versus nafcillin) were significantly associated with relapse. Recurrences occurred in 9.4% of S. aureus bacteremias following antistaphylococcal therapy, and most were relapses. Duration of antistaphylococcal therapy was not associated with relapse, but type of antibiotic therapy was. Nafcillin was superior to vancomycin in efficacy in patients with MSSA bacteremia. more

Topics: Bacteremia (61%), Vancomycin (57%), Nafcillin (53%) more

470 Citations

Journal ArticleDOI: 10.1016/J.COLSURFB.2008.09.021
Abstract: We report a novel strategy for the biological synthesis of anisotropic gold and quasi-spherical silver nanoparticles by using apiin as the reducing and stabilizing agent. The size and shape of the nanoparticles can be controlled by varying the ratio of metal salts to apiin compound in the reaction medium. The resultant nanoparticles were characterized by UV-vis-NIR, transmission electron microscopy (TEM), FT-IR spectroscopy, X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The interaction between nanoparticles with carbonyl group of apiin compound was confirmed by using FT-IR analysis. TEM photograph confirming the average size of the gold and silver nanoparticles were found to be at 21 and 39 nm. The NIR absorption of the gold nanotriangles is expected to be of application in hyperthermia of cancer cells and in IR-absorbing optical coatings. more

Topics: Apiin (69%), Silver nanoparticle (61%), Colloidal gold (57%) more

443 Citations

Open accessJournal ArticleDOI: 10.1172/JCI38226
Frank R. DeLeo1, Henry F. ChambersInstitutions (1)
Abstract: Staphylococcus aureus is the leading cause of bacterial infections in developed countries and produces a wide spectrum of diseases, ranging from minor skin infections to fatal necrotizing pneumonia. Although S. aureus infections were historically treatable with common antibiotics, emergence of drug-resistant organisms is now a major concern. Methicillin-resistant S. aureus (MRSA) was endemic in hospitals by the late 1960s, but it appeared rapidly and unexpectedly in communities in the 1990s and is now prevalent worldwide. This Review focuses on progress made toward understanding the success of community-associated MRSA as a human pathogen, with an emphasis on genome-wide approaches and virulence determinants. more

440 Citations

Journal ArticleDOI: 10.1021/JF0340308
Abstract: The present study was designated to evaluate the antimicrobial and antioxidant activities of the essential oil, obtained by using a Clevenger distillation apparatus, water soluble (polar) and water insoluble (nonpolar) subfractions of the methanol extracts from aerial parts of Satureja hortensis L plants, and methanol extract from calli established from the seeds using Gamborg's B5 basal media supplemented with indole-3-butyric acid (10 ppm), 6-benzylaminopurine (N(6)-benzyladenine) (10 ppm), and sucrose (25%) The antimicrobial test results showed that the essential oil of S hortensis had great potential antimicrobial activities against all 23 bacteria and 15 fungi and yeast species tested In contrast, the methanol extract from callus cultures and water soluble subfraction of the methanol extract did not show antimicrobial activities, but the nonpolar subfraction had antibacterial activity against only five out of 23 bacterial species, which were Bacillus subtilis, Enterococcus fecalis, Pseudomonas aeruginosa, Salmonella enteritidis, and Streptococcus pyogenes Antioxidant studies suggested that the polar subfractions of the methanol extract of intact plant and methanol extract of callus cultures were able to reduce the stable free radical 2,2-diphenyl-1-picrylhydrazyl to the yellow-colored diphenylpicrylhydrazine In this assay, the strongest effect was observed for the tissue culture extract, with an IC(50) value of 2376 +/- 080 microgram/mL, which could be compared with the synthetic antioxidant agent butylated hydroxytoluene On the other hand, linoleic acid oxidation was 95% inhibited in the presence of the essential oil while the inhibition was 90% with the chloroform subfraction of the intact plant The chemical composition of a hydrodistilled essential oil of S hortensis was analyzed by gas chromatography (GC)/flame ionization detection (FID) and a GC-mass spectrometry system A total 22 constituents representing 999% of the essential oil were identified by GC-FID analaysis Thymol (290%), carvacrol (265%), gamma-terpinene (226%), and p-cymene (93%) were the main components more

Topics: Essential oil (58%), Carvacrol (54%), Thymol (52%) more

398 Citations

Open accessJournal ArticleDOI: 10.1016/J.JSCS.2012.04.007
Abstract: Plants extract from Ocimum tenuiflorum , Solanum tricobatum , Syzygium cumini , Centella asiatica and Citrus sinensis was used for the synthesis of silver nanoparticles (Ag NPs) from silver nitrate solution. Ag NPs were characterized by UV–vis spectrophotometer, X-ray diffractometer (XRD), atomic force microscope (AFM) and scanning electron microscope (SEM). The formation and stability of the reduced silver nanoparticles in the colloidal solution were monitored by UV–vis spectrophotometer analysis. The mean particle diameter of silver nanoparticles was calculated from the XRD pattern according to the line width of the plane, refraction peak using the Scherrer’s equation. AFM showed the formation of silver nanoparticle with an average size of 28 nm, 26.5 nm, 65 nm, 22.3 nm and 28.4 nm corresponding to O. tenuiflorum , S. cumini , C. sinensis , S. tricobatum and C. asiatica, respectively. SEM determination of the brown color stable samples showed the formation of silver nanoparticles and well dispersed nanoparticles could be seen in the samples treated with silver nitrate. Antimicrobial activity of the silver bio-nanoparticles was performed by well diffusion method against Staphylococcus aureus , Pseudomonas aeruginosa , Escherichia coli and Klebsiella pneumoniae . The highest antimicrobial activity of silver nanoparticles synthesized by S. tricobatum , O. tenuiflorum extracts was found against S. aureus (30 mm) and E. coli (30 mm) respectively. The Ag NPs synthesized in this process has the efficient antimicrobial activity against pathogenic bacteria. Of these, silver nanoparticles are playing a major role in the field of nanotechnology and nanomedicine. more

Topics: Silver nanoparticle (69%), Silver nitrate (67%)

353 Citations