Displaying publications 241 - 260 of 689 in total

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  1. Fulltext Antimicrobial Activity of Novel Synthetic Peptides Derived from Indolicidin and Ranalexin against Streptococcus pneumoniae
    Jindal HM, Le CF, Mohd Yusof MY, Velayuthan RD, Lee VS, Zain SM, et al.
    PLoS One, 2015;10(6):e0128532.
    PMID: 26046345 DOI: 10.1371/journal.pone.0128532
    Antimicrobial peptides (AMPs) represent promising alternatives to conventional antibiotics in order to defeat multidrug-resistant bacteria such as Streptococcus pneumoniae. In this study, thirteen antimicrobial peptides were designed based on two natural peptides indolicidin and ranalexin. Our results revealed that four hybrid peptides RN7-IN10, RN7-IN9, RN7-IN8, and RN7-IN6 possess potent antibacterial activity against 30 pneumococcal clinical isolates (MIC 7.81-15.62µg/ml). These four hybrid peptides also showed broad spectrum antibacterial activity (7.81µg/ml) against S. aureus, methicillin resistant S. aureus (MRSA), and E. coli. Furthermore, the time killing assay results showed that the hybrid peptides were able to eliminate S. pneumoniae within less than one hour which is faster than the standard drugs erythromycin and ceftriaxone. The cytotoxic effects of peptides were tested against human erythrocytes, WRL-68 normal liver cell line, and NL-20 normal lung cell line. The results revealed that none of the thirteen peptides have cytotoxic or hemolytic effects at their MIC values. The in silico molecular docking study was carried out to investigate the binding properties of peptides with three pneumococcal virulent targets by Autodock Vina. RN7IN6 showed a strong affinity to target proteins; autolysin, pneumolysin, and pneumococcal surface protein A (PspA) based on rigid docking studies. Our results suggest that the hybrid peptides could be suitable candidates for antibacterial drug development.
    Matched MeSH terms: Staphylococcus aureus/drug effects; Methicillin-Resistant Staphylococcus aureus/drug effects
  2. The Evaluation of Different Bacteriocinogenic Bacillus spp. with Activity Against Staphylococcus spp. and Their Beneficial and/or Hazardous Properties
    Fugaban JII, Dioso CM, Choi GH, Bucheli JEV, Liong MT, Holzapfel WH, et al.
    Probiotics Antimicrob Proteins, 2024 Feb;16(1):35-52.
    PMID: 36445687 DOI: 10.1007/s12602-022-10017-7
    The aim of this project was to screen for bacteriocinogenic Bacillus strains with activity versus Staphylococcus spp. with future application in formulation of pharmaceutical antimicrobial preparations. Putative bacteriocinogenic strains, isolated and pre-identified as Bacillus spp. were selected for future study and differentiated based on repPCR and identified as Bacillus subtilis for strains ST826CD and ST829CD, Bacillus subtilis subsp. stercoris for strain ST794CD, Bacillus subtilis subsp. spizizenii for strain ST824CD, Bacillus velezensis for strain ST796CD, and Bacillus tequilensis for strain ST790CD. Selected strains were evaluated regarding their safety/virulence, beneficial properties, and potential production of antimicrobials based on biomolecular and physiological approves. Expressed bacteriocins were characterized regarding their proteinaceous nature, stability at different levels of pH, temperatures, and the presence of common chemicals applied in bacterial cultivation and bacteriocin purification. Dynamic of bacterial growth, acidification, and cumulation of produced bacteriocins and some aspects of the bacteriocins mode of action were evaluated. Based on obtained results, isolation and application of expressed antimicrobials can be realistic scenario for treatment of some staphylococcal associated infections. Appropriate biotechnological approaches need to be developed for cost effective production, isolation, and purification of expressed antimicrobials by studied Bacillus strains.
    Matched MeSH terms: Staphylococcus
  3. Marine-derived κ-carrageenan-coated zinc oxide nanoparticles for targeted drug delivery and apoptosis induction in oral cancer
    Marunganathan V, Kumar MSK, Kari ZA, Giri J, Shaik MR, Shaik B, et al.
    Mol Biol Rep, 2024 Jan 07;51(1):89.
    PMID: 38184807 DOI: 10.1007/s11033-023-09146-1
    BACKGROUND: Kappaphycus alvarezii, a marine red algae species, has gained significant attention in recent years due to its versatile bioactive compounds. Among these, κ-carrageenan (CR), a sulfated polysaccharide, exhibits remarkable antimicrobial properties. This study emphasizes the synergism attained by functionalizing zinc oxide nanoparticles (ZnO NPs) with CR, thereby enhancing its antimicrobial efficacy and target specificity against dental pathogens.

    METHODS: In this study, we synthesized ZnO-CR NPs and characterized them using SEM, FTIR, and XRD techniques to authenticate their composition and structural attributes. Moreover, our investigation revealed that ZnO-CR NPs possess better free radical scavenging capabilities, as evidenced by their effective activity in the DPPH and ABTS assay.

    RESULTS: The antimicrobial properties of ZnO-CR NPs were systematically assessed using a zone of inhibition assay against dental pathogens of S. aureus, S. mutans, E. faecalis, and C. albicans, demonstrating their substantial inhibitory effects at a minimal concentration of 50 μg/mL. We elucidated the interaction between CR and the receptors of dental pathogens to further understand their mechanism of action. The ZnO-CR NPs demonstrated a dose-dependent anticancer effect at concentrations of 5 μg/mL, 25 μg/mL, 50 μg/mL, and 100 μg/mL on KB cells, a type of Human Oral Epidermal Carcinoma. The mechanism by which ZnO-CA NPs induced apoptosis in KB cells was determined by observing an increase in the expression of the BCL-2, BAX, and P53 genes.

    CONCLUSION: Our findings unveil the promising potential of ZnO-CR NPs as a candidate with significant utility in dental applications. The demonstrated biocompatibility, potent antioxidant and antiapoptotic activity, along with impressive antimicrobial efficacy position these NPs as a valuable resource in the ongoing fight against dental pathogens and oral cancer.

    Matched MeSH terms: Staphylococcus aureus
  4. Fulltext Glottic Staphylococcus aureus in a patient with systemic lupus erythematosus: videolaryngostroboscopic characteristics
    Mohd Ramli SS, Mat Baki M
    BMJ Case Rep, 2022 Feb 28;15(2).
    PMID: 35228218 DOI: 10.1136/bcr-2021-245840
    Systemic lupus erythematous (SLE) is an autoimmune disease commonly treated with steroid which leads to immunosuppression and increased susceptibility to infection. Chronic laryngitis with whitish lesion on the true vocal fold in SLE may be caused by opportunistic organisms, such as tuberculous, fungal and Staphylococcus aureus infections. Videolaryngostroboscopy may be helpful in leading to the diagnosis and optimum treatment of glottic S. aureus A woman in her 40s with SLE presented with progressively worsening hoarseness for 2 months, accompanied by sore throat and odynophagia. Videoendoscopy showed erythematous and oedematous bilateral vocal fold with whitish lesion seen at the edge of middle one-third while the videolaryngostroboscopic evaluation showed there was severe asymmetry of the bilateral vocal folds, with severely reduced amplitude during phonation where the vocal cords were not vibrating, aperiodic vibratory cycles and 'always open', incomplete closure of vocal cord pattern. Later, endolaryngeal microsurgery and biopsy of the lesion confirmed of glottic S. aureus Her symptoms and followed up videolaryngostroboscopy showed resolution to normal findings after 6 weeks of cloxacillin. S. aureus infection of the glottis is a differential diagnosis in a chronic laryngitis with leucoplakic lesion in an immunosuppressive patient. Videolaryngostroboscopy has an important role in diagnosis, evaluation and treatment decision.
    Matched MeSH terms: Staphylococcus aureus
  5. Fulltext Topical Nanoemulsion Hydrogel Formulated from Supercritical Fluid Extracted Palm-Pressed Fiber Oil and Virgin Coconut Oil with Antioxidant and Antibacterial Effects
    Mah SH, Sundrasegaran S, Lau HLN
    J Oleo Sci, 2024;73(4):489-502.
    PMID: 38556283 DOI: 10.5650/jos.ess23197
    Skincare industries are growing rapidly around the globe but most products are formulated using synthetic chemicals and organic solvent extracted plant extracts, thus may be hazardous to the users and incur higher cost for purification that eventually leads to phytonutrient degradation. Therefore, this study aimed to formulate a stable natural formulation with antioxidant and antimicrobial activities by using supercritical carbon dioxide (SC-CO 2 ) extracted palm-pressed fiber oil (PPFO) as an active ingredient with virgin coconut oil (VCO) as a formulation base. PPFO was extracted from fresh palm-pressed fiber (PPF) while VCO was from dried grated coconut copra using SC-CO 2 before being subjected to the analyses of physicochemical properties, phytonutrient content and biological activities including antioxidant and antimicrobial. The nanoemulgel formulations were then developed and examined for their stability through accelerated stability study for 3 months by measuring their pH, particle size, polydispersity index and zeta potential. The results showed that PPFO contained a high amount of phytonutrients, especially total carotenoid (1497 ppm) and total tocopherol and tocotrienol (2269 ppm) contents. The newly developed nanoemulgels maintained their particles in nano size and showed good stability with high negative zeta potentials. Sample nanoemulgel formulated with 3% PPFO diluted in VCO as effective concentration showed significantly stronger antioxidant activity than the control which was formulated from 3% tocopheryl acetate diluted in mineral oil, towards DPPH and ABTS radicals, with IC 50 values of 67.41 and 44.28 µL/mL, respectively. For the antibacterial activities, the sample nanoemulgel was found to inhibit Gram positive bacteria S. aureus and S. epidermidis growth but not the Gram negative strain E. coli. Overall, this study revealed the potential of SF-extracted PPFO as an active ingredient in the antioxidant topical formulations thus future study on in vitro skin cell models is highly recommended for validation.
    Matched MeSH terms: Staphylococcus aureus
  6. Fulltext Green synthesis of silver/montmorillonite/chitosan bionanocomposites using the UV irradiation method and evaluation of antibacterial activity
    Shameli K, Ahmad MB, Yunus WM, Rustaiyan A, Ibrahim NA, Zargar M, et al.
    Int J Nanomedicine, 2010 Oct 22;5:875-87.
    PMID: 21116328 DOI: 10.2147/IJN.S13632
    In this study, silver nanoparticles (Ag-NPs) were synthesized using a green physical synthetic route into the lamellar space of montmorillonite (MMT)/chitosan (Cts) utilizing the ultraviolet (UV) irradiation reduction method in the absence of any reducing agent or heat treatment. Cts, MMT, and AgNO(3) were used as the natural polymeric stabilizer, solid support, and silver precursor, respectively. The properties of Ag/MMT/Cts bionanocomposites (BNCs) were studied as the function of UV irradiation times. UV irradiation disintegrated the Ag-NPs into smaller sizes until a relatively stable size and size distribution were achieved. Meanwhile, the crystalline structure and d-spacing of the MMT interlayer, average size and size distribution, surface morphology, elemental signal peaks, functional groups, and surface plasmon resonance of Ag/MMT/Cts BNCs were determined by powder X-ray diffraction, transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray fluorescence, Fourier transform infrared, and UV-visible spectroscopy. The antibacterial activity of Ag-NPs in MMT/Cts was investigated against Gram-positive bacteria, ie, Staphylococcus aureus and methicillin-resistant S. aureus and Gram-negative bacteria (ie, Escherichia coli) by the disk diffusion method on Muller-Hinton Agar at different sizes of Ag-NPs. All of the synthesized Ag/MMT/Cts BNCs were found to have high antibacterial activity. These results show that Ag/MMT/Cts BNCs can be useful in different biologic research and biomedical applications, such as surgical devices and drug delivery vehicles.
    Matched MeSH terms: Staphylococcus aureus/drug effects; Methicillin-Resistant Staphylococcus aureus/drug effects
  7. Fulltext Genotypically different clones of Staphylococcus aureus are diverse in the antimicrobial susceptibility patterns and biofilm formations
    Atshan SS, Nor Shamsudin M, Lung LT, Sekawi Z, Pei Pei C, Karunanidhi A, et al.
    Biomed Res Int, 2013;2013:515712.
    PMID: 24455699 DOI: 10.1155/2013/515712
    This study evaluated whether genotypically different clinical isolates of S. aureus have similar susceptibilities to individual antibiotics. It further aims to check the impact of biofilm on the in vitro activity of vancomycin, daptomycin, linezolid, and tigecycline against S. aureus clones. The study used a total of 60 different clinical MSSA and MRSA isolates. Susceptibilities were performed in planktonic cultures by macrobroth dilution and epsilon-test (E test) system. Biofilm production was determined using an adherent plate assay. The efficacy of antimicrobial activities against biofilms formation was checked using confocal laser scanning microscopy (CLSM). The study found that similar and different spa, MLST, and SCCmec types displayed high variation in their susceptibilities to antibiotics with tigecycline and daptomycin being the most effective. The biofilms were found resistant to high concentrations of most antibiotics tested with daptomycin being the most effective drug used in adhesive biofilms. A considerable difference exists among similar and various clone types against antibiotics tested. This variation could have contributed to the degree of virulence even within the same clonal genotype and enhanced heterogeneity in the infection potential. Thus, the development of a rapid and precise identification profile for each clone in human infections is important.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/drug effects*; Methicillin-Resistant Staphylococcus aureus/genetics*; Methicillin-Resistant Staphylococcus aureus/growth & development
  8. Fulltext Prevalence of ST9 methicillin-resistant Staphylococcus aureus among pigs and pig handlers in Malaysia
    Neela V, Mohd Zafrul A, Mariana NS, van Belkum A, Liew YK, Rad EG
    J Clin Microbiol, 2009 Dec;47(12):4138-40.
    PMID: 19812280 DOI: 10.1128/JCM.01363-09
    Methicillin-resistant Staphylococcus aureus (MRSA) of sequence type 398 (ST398) has frequently been detected in pigs and pig handlers. However, in Malaysia, sampling 360 pigs and 90 pig handlers from 30 farms identified novel ST9-spa type t4358-staphylococcal cassette chromosome mec type V MRSA strains that were found to transiently colonize more than 1% of pigs and 5.5% of pig handlers.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/classification; Methicillin-Resistant Staphylococcus aureus/genetics; Methicillin-Resistant Staphylococcus aureus/isolation & purification*
  9. Fulltext Staphylococcus aureus carriage in selected kindergartens in Klang Valley
    Mohamed NA, Ramli S, Amin NN, Sulaiman WS, Isahak I, Jamaluddin TZ, et al.
    Med J Malaysia, 2016 04;71(2):62-5.
    PMID: 27326943 MyJurnal
    INTRODUCTION: Nasal colonisation of S. aureus in healthy children was 18% to 30%. One to three percent of them were colonised by Methicillin-resistant Staphlycoccus aureus (MRSA). Although MRSA infection has become increasingly reported, population-based S. aureus and MRSA colonisation estimates are lacking. The main objective of this study was to determine the prevalence of S. aureus carriage among children.

    METHODS: Nasal samples for S. aureus culture were obtained from 250 children from three kindergartens in the Klang Valley, after consent was obtained from the children and their parents. Swabs were transported in Stuart medium, and inoculated on mannitol-salt agar within four hours of collection. Identification and disk diffusion test were done according to guidelines. Polymerase chain reaction was done on MRSA isolates for the presence of mecA and lukS/FPV genes.

    RESULTS: Overall prevalence of S. aureus and MRSA carriage were 19.2% (48/250) and 1.6% (4/250) respectively. mecA gene was present in all isolates, 50% isolates carried Panton-Valentine leucocidin (PVL) gene. Sccmec type I was found in 2 isolates and the remaining isolates has Sccmec type V.

    CONCLUSION: The prevalence of S. aureus and MRSA carriage were similar to other studies. However, risk of contracting severe infection might be higher due to presence of PVL gene in half of the MRSA isolates.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/isolation & purification*
  10. Antibacterial properties of poly (octanediol citrate)/gallium-containing bioglass composite scaffolds
    Zeimaran E, Pourshahrestani S, Djordjevic I, Pingguan-Murphy B, Kadri NA, Wren AW, et al.
    J Mater Sci Mater Med, 2016 Jan;27(1):18.
    PMID: 26676864 DOI: 10.1007/s10856-015-5620-2
    Bioactive glasses may function as antimicrobial delivery systems through the incorporation and subsequent release of therapeutic ions. The aim of this study was to evaluate the antimicrobial properties of a series of composite scaffolds composed of poly(octanediol citrate) with increased loads of a bioactive glass that releases zinc (Zn(2+)) and gallium (Ga(3+)) ions in a controlled manner. The antibacterial activity of these scaffolds was investigated against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The ability of the scaffolds to release ions and the subsequent ingress of these ions into hard tissue was evaluated using a bovine bone model. Scaffolds containing bioactive glass exhibited antibacterial activity and this increased in vitro with higher bioactive glass loads; viable cells decreased to about 20 % for the composite scaffold containing 30 % bioactive glass. The Ga(3+) release rate increased as a function of time and Zn(2+) was shown to incorporate into the surrounding bone.
    Matched MeSH terms: Staphylococcus aureus/growth & development
  11. Fulltext Antibacterial activity of leaf extracts of Baeckea frutescens against methicillin-resistant Staphylococcus aureus
    Razmavar S, Abdulla MA, Ismail SB, Hassandarvish P
    Biomed Res Int, 2014;2014:521287.
    PMID: 25028658 DOI: 10.1155/2014/521287
    This study was based on screening antibacterial activity of the ethanol extract of Baeckea frutescens L. against MRSA clinical isolates, analyzes the potential antibacterial compound, and assesses the cytotoxicity effect of the extract in tissue culture. Leaves of Baeckea frutescens L. were shade dried, powdered, and extracted using solvent ethanol. Preliminary phytochemical screening of the crude extracts revealed the presence of alkaloids, flavonoids, steroids, terpenoids, phenols, and carbohydrates. The presence of these bioactive constituents is related to the antibacterial activity of the plant. Disc diffusion method revealed a high degree of activity against microorganisms. The results confirm that Baeckea frutescens L. can be used as a source of drugs to fight infections caused by susceptible bacteria.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/growth & development*
  12. Fulltext Methicillin-resistant Staphylococcus aureus nasal carriage among patients and healthcare workers in a hospital in Kelantan, Malaysia
    Al-Talib H, Yean CY, Hasan H, Nik Zuraina NM, Ravichandran M
    Pol J Microbiol, 2013;62(1):109-12.
    PMID: 23829087
    Staphylococcus aureus nasal carriage is a common source of nosocomial infection and colonization. The aim of the present study was to assess the burden of methicillin-resistant S. aureus nasal carriage, its association with factors of interest including its genetic relationships. The prevalence of S. aureus nasal carriage was found to be 28.7%. This study showed that patients with a history of previous antibiotic intake, nasogastric tube, and longer hospitalization had a significantly high risk of being MRSA nasal carriers. The genetic relationship of all 34 nasal MRSA isolates revealed four major clusters of isolates, and there was a relationship between MRSA isolated from inpatients and healthcare workers.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/isolation & purification*
  13. Fulltext Synthesis, antibacterial and thermal studies of cellulose nanocrystal stabilized ZnO-Ag heterostructure nanoparticles
    Azizi S, Ahmad MB, Hussein MZ, Ibrahim NA
    Molecules, 2013 May 28;18(6):6269-80.
    PMID: 23760028 DOI: 10.3390/molecules18066269
    Synthesis of ZnO-Ag heterostructure nanoparticles was carried out by a precipitation method with cellulose nanocrystals (CNCs) as a stabilizer for antimicrobial and thermal studies. ZnO-Ag nanoparticles were obtained from various weight percentages of added AgNO₃ relative to Zn precursors for evaluating the best composition with enhanced functional properties. The ZnO-Ag/CNCs samples were characterized systematically by TEM, XRD, UV, TGA and DTG. From the TEM studies we observed that ZnO-Ag heterostructure nanoparticles have spherical shapes with size diameters in a 9-35 nm range. The antibacterial activities of samples were assessed against the bacterial species Salmonella choleraesuis and Staphylococcus aureus. The CNC-stabilized ZnO-Ag exhibited greater bactericidal activity compared to cellulose-free ZnO-Ag heterostructure nanoparticles of the same particle size. The incorporation of ZnO-Ag hetreostructure nanoparticles significantly increased the thermal stability of cellulose nanocrystals.
    Matched MeSH terms: Staphylococcus aureus/drug effects
  14. Synergy of flavone with vancomycin and oxacillin against vancomycin-intermediate Staphyloccus aureus
    Bakar NS, Zin NM, Basri DF
    Pak J Pharm Sci, 2012 Jul;25(3):633-8.
    PMID: 22713953
    This study evaluated in vitro activity of 9 flavonoids in combination with vancomycin or oxacillin against vancomycin-intermediate Staphylococcus aureus (VISA) ATCC 700699 by employing the checkerboard method to obtain Minimal inhibitory concentration (MIC) and fractional inhibitory concentration (FIC) index. Six flavonoids namely hesperitin, rutin, naringenin, flavones, naringin and 3, 7-dihyroxyflavone which exhibited notable inhibitory activity (MIC values < 3200 μg/ml) were further evaluated for combination assay with antibiotics. The combinations of vancomycin+flavone and oxacillin+flavone were found synergistic with the FIC index value 0.094 and 0.126, respectively. Other combinations showed an additive interaction (FIC index = 1.063) but no antagonistic reaction (FIC index > 4) were observed. In time kill studies, oxacillin-flavone combination at synergistic concentration demonstrated bactericidal effect at 24 h period with concentration-dependent manner on the VISA strain. Following 1 h exposure, the combination also produced persistent effect on the bacteria growth for 2.9 hrs at 1x sub-MIC and more than 24 h at 5x of sub-MIC and there was a significant difference between both concentrations (p<0.05). Vancomycin-flavone combination, however, showed no concentration-dependent effect and lower PAE values (1.159 h and 2.322 h at 1x and 5x sub-MIC, respectively) on the VISA strain. In conclusion, flavone markedly intensifies the susceptibility of oxacillin against VISA and the combination can be implicated for further interaction studies at molecular level.
    Matched MeSH terms: Staphylococcus aureus/drug effects*
  15. Synthesis and anti-microbial activity of hydroxylammonium ionic liquids
    Ismail Hossain M, El-Harbawi M, Noaman YA, Bustam MA, Alitheen NB, Affandi NA, et al.
    Chemosphere, 2011 Jun;84(1):101-4.
    PMID: 21421256 DOI: 10.1016/j.chemosphere.2011.02.048
    Eight hydroxylammonium-based room temperature ionic liquids (ILs) have been synthesized by acid-base neutralization of ethanolamines with organic acids. The ILs were characterized by infrared and nuclear magnetic resonance spectroscopies and elemental analysis. Their anti-microbial activities were determined using the well-diffusion method. All eight ILs were toxic to Staphylococcus aureus, while 2-hydroxyethylammonium lactate and 2-hydroxy-N-(2-hydroxyethyl)-N-methylethanaminium acetate showed high anti-microbial activity against a wide range of human pathogens.
    Matched MeSH terms: Staphylococcus aureus/drug effects*
  16. Fulltext An antimicrobial compound isolated from Cinnamomum iners leaves with activity against methicillin-resistant Staphylococcus aureus
    Mustaffa F, Indurkar J, Ismail S, Shah M, Mansor SM
    Molecules, 2011 Apr 08;16(4):3037-47.
    PMID: 21478819 DOI: 10.3390/molecules16043037
    This study was designed to investigate the antimicrobial activity of Cinnamomum iners standardized leave methanolic extract (CSLE), its fractions and isolated compounds. CSLE and fractions were subjected to disc diffusion, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests using different Gram positive and Gram negative bacteria and yeast. Within the series of fractions tested, the ethyl acetate fraction was the most active, particularly against methicillin resistant Staphylococcus aureus (MRSA) and Escherichia coli, with MIC values of 100 and 200 µg/mL, respectively. The active compound in this fraction was isolated and identified as xanthorrhizol [5-(1, 5-dimethyl-4-hexenyl)-2-methylphenol] by various spectroscopic techniques. The overall results of this study provide evidence that Cinnamomum iners leaves extract as well as the isolated compound xanthorrhizol exhibit antimicrobial activity for both Gram negative and Gram positive pathogens, especially against MRSA strains.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/drug effects*
  17. Chemical constituents and antibacterial activity of Melastoma malabathricum L
    Wong KC, Hag Ali DM, Boey PL
    Nat Prod Res, 2012;26(7):609-18.
    PMID: 21834640 DOI: 10.1080/14786419.2010.538395
    The aqueous methanolic extracts of Melastoma malabathricum L. exhibited antibacterial activity when assayed against seven microorganisms by the agar diffusion method. Solvent fractionation afforded active chloroform and ethyl acetate fractions from the leaves and the flowers, respectively. A phytochemical study resulted in the identification of ursolic acid (1), 2α-hydroxyursolic acid (2), asiatic acid (3), β-sitosterol 3-O-β-D-glucopyranoside (4) and the glycolipid glycerol 1,2-dilinolenyl-3-O-β-D-galactopyanoside (5) from the chloroform fraction. Kaempferol (6), kaempferol 3-O-α-L-rhamnopyranoside (7), kaempferol 3-O-β-D-glucopyranoside (8), kaempferol 3-O-β-D-galactopyranoside (9), kaempferol 3-O-(2″,6″-di-O-E-p-coumaryl)-β-D-galactopyranoside (10), quercetin (11) and ellagic acid (12) were found in the ethyl acetate fraction. The structures of these compounds were determined by chemical and spectral analyses. Compounds 1-4, the flavonols (6 and 11) and ellagic acid (12) were found to be active against some of the tested microorganisms, while the kaempferol 3-O-glycosides (7-9) did not show any activity, indicating the role of the free 3-OH for antibacterial activity. Addition of p-coumaryl groups results in mild activity for 10 against Staphylococcus aureus and Bacillus cereus. Compounds 2-5, 7 and 9-12 are reported for the first time from M. malabathricum. Compound 10 is rare, being reported only once before from a plant, without assignment of the double bond geometry in the p-coumaryl moiety.
    Matched MeSH terms: Staphylococcus aureus/drug effects*
  18. Fulltext Synergistic antimicrobial activity between pentacyclic triterpenoids and antibiotics against Staphylococcus aureus strains
    Chung PY, Navaratnam P, Chung LY
    Ann Clin Microbiol Antimicrob, 2011;10:25.
    PMID: 21658242 DOI: 10.1186/1476-0711-10-25
    There has been considerable effort to discover plant-derived antibacterials against methicillin-resistant strains of Staphylococcus aureus (MRSA) which have developed resistance to most existing antibiotics, including the last line of defence, vancomycin. Pentacyclic triterpenoid, a biologically diverse plant-derived natural product, has been reported to show anti-staphylococcal activities. The objective of this study is to evaluate the interaction between three pentacyclic triterpenoid and standard antibiotics (methicillin and vancomycin) against reference strains of Staphylococcus aureus.
    Matched MeSH terms: Staphylococcus aureus/drug effects*
  19. Fulltext Expression of an organic solvent stable lipase from Staphylococcus epidermidis AT2
    Rahman RN, Kamarudin NH, Yunus J, Salleh AB, Basri M
    Int J Mol Sci, 2010;11(9):3195-208.
    PMID: 20957088 DOI: 10.3390/ijms11093195
    An organic solvent tolerant lipase gene from Staphylococcus epidermidis AT2 was successfully cloned and expressed with pTrcHis2 in E. coli TOP10. Sequence analysis revealed an open reading frame (ORF) of 1,933 bp in length which coded for a polypeptide of 643 amino acid residues. The polypeptide comprised of a signal peptide (37 amino acids), pro-peptide and a mature protein of 390 amino acids. Expression of AT2 lipase resulted in an 18-fold increase in activity, upon the induction of 0.6 mM IPTG after a 10 h incubation period. Interestingly, this lipase was stable in various organic solvents (25% (v/v), mainly toluene, octanol, p-xylene and n-hexane). Literature shows that most of the organic solvent stable bacterial lipases were produced by Pseudomonas sp. and Bacillus sp., but very few from Staphylococcus sp. This lipase demonstrates great potential to be employed in various industrial applications.
    Matched MeSH terms: Staphylococcus epidermidis/enzymology*
  20. Fulltext High prevalence of methicillin-resistant Staphylococcus aureus (MRSA) on doctors' neckties
    Koh KC, Husni S, Tan JE, Tan CW, Kunaseelan S, Nuriah S, et al.
    Med J Malaysia, 2009 Sep;64(3):233-5.
    PMID: 20527275 MyJurnal
    We set out to investigate whether neckties worn by doctors are more likely to be contaminated with Methicillin resistant Staphylococcus aureus (MRSA) compared to neckties worn by preclinical medical undergraduates who have never been exposed to a hospital environment. We discovered that more than half (52%) of neckties worn by doctors were contaminated with Staphylococcus and out of these, 62% of them were identified as MRSA. In contrast, none of the student's ties were contaminated with MRSA. Due to the high prevalence of staphylococcus detected on doctors' neckties, we recommend that health care workers do not wear neckties.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/isolation & purification*
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