Displaying publications 41 - 60 of 608 in total

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  1. Lee ML, Tan NH, Fung SY, Sekaran SD
    PMID: 21059402 DOI: 10.1016/j.cbpc.2010.11.001
    The major l-amino acid oxidase (LAAO, EC 1.4.3.2) of king cobra (Ophiophagus hannah) venom is known to be an unusual form of snake venom LAAO as it possesses unique structural features and unusual thermal stability. The antibacterial effects of king cobra venom LAAO were tested against several strains of clinical isolates including Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli using broth microdilution assay. For comparison, the antibacterial effects of several antibiotics (cefotaxime, kanamycin, tetracycline, vancomycin and penicillin) were also examined using the same conditions. King cobra venom LAAO was very effective in inhibiting the two Gram-positive bacteria (S. aureus and S. epidermidis) tested, with minimum inhibitory concentration (MIC) of 0.78μg/mL (0.006μM) and 1.56μg/mL (0.012μM) against S. aureus and S. epidermidis, respectively. The MICs are comparable to the MICs of the antibiotics tested, on a weight basis. However, the LAAO was only moderately effective against three Gram-negative bacteria tested (P. aeruginosa, K. pneumoniae and E. coli), with MIC ranges from 25 to 50μg/mL (0.2-0.4μM). Catalase at the concentration of 1mg/mL abolished the antibacterial effect of LAAO, indicating that the antibacterial effect of the enzyme involves generation of hydrogen peroxide. Binding studies indicated that king cobra venom LAAO binds strongly to the Gram-positive S. aureus and S. epidermidis, but less strongly to the Gram-negative E. coli and P. aeruginosa, indicating that specific binding to bacteria is important for the potent antibacterial activity of the enzyme.
    Matched MeSH terms: Staphylococcus aureus/drug effects
  2. Mogana R, Adhikari A, Tzar MN, Ramliza R, Wiart C
    BMC Complement Med Ther, 2020 Feb 14;20(1):55.
    PMID: 32059725 DOI: 10.1186/s12906-020-2837-5
    BACKGROUND: Canarium patentinervium leaves are used by the local indigenous people of Malaysia for wound healing. The current study is undertaken to screen the comprehensive antibacterial activity of the leaves and barks extracts, fractions and isolated compounds from this plant. Bioassay guided fractionation was also undertaken to deeply evaluate the antibacterial activity of the water fraction of the leaves extract. This is to provide preliminary scientific evidence to the ethnopharmacology usage of this plant by investigating antibacterial properties of the plant and its isolated constituents.

    METHODS: Bio-assay guided fractionation and subsequent isolation of compounds using open column chromatography. The antibacterial activity against gram positive and gram negative ATCC strain and resistant clinical strains were evaluated using microtiter broth dilution method to determine minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and time-kill assay. The chemical structure of the isolated compounds from the water fraction of the ethanol extract of leaves was elucidated using Nuclear Magnetic Resonance (NMR).

    RESULTS: The ethanol extract of the leaves and barks showed antimicrobial activity against all four ATCC and eight clinical isolates. The ethanol extract of the leaves and the corresponding water fraction had good activity against MRSA S. aureus. (MIC: 250 μg/ml) and had bactericidal effect on eight of the clinical strains (MSSA,MRSA, oxacillin-resistant CONS, oxacillin-sensitive CONS, Enterococcus faecalis, Klebsiela species, Kleb pneumoniae ESBL and Candida parapsilosis). Further phytochemical investigation of the water fraction of the crude ethanol extract of leaves afforded compound 7 (hyperin) and compound 8 (cynaroside) that had bactericidal activity against tested bacterial species (MIC 50 μg/ml and 100 μg/ml). The two compounds were isolated from this genus for the first time.

    CONCLUSIONS: These results may provide a rational support for the traditional use of Canarium patentinervium Miq. in infections and wound healing, since the antimicrobial compounds isolated were also present in the leaves extract.

    Matched MeSH terms: Staphylococcus aureus; Methicillin-Resistant Staphylococcus aureus
  3. Qaralleh HN, Abboud MM, Khleifat KM, Tarawneh KA, Althunibat OY
    Pak J Pharm Sci, 2009 Jul;22(3):247-51.
    PMID: 19553168
    This study was carried out to evaluate the antibacterial activity of aqueous and organic extracts of Thymus capitatus L. (Lamiaceae) leaves and stems. Dried ground powder leaves and stems were extracted with water (aqueous extracts), ethanol, dichloromethane and hexane (Soxhlet extracts). The antibacterial activity of these extracts was evaluated against bacteria using disc diffusion method. The result obtained showed that the leaves had stronger antibacterial activity than the stems extracts. The ethanolic extract had the highest yield products and the high antibacterial activity than all other solvents. The results suggest that essential oil as non-polar organic compounds could be the main active compounds in this plant. Therefore the antibacterial activity of leaves ethanol extracts (LEE) was compared with essential oils leaves extracts (LEO) of T. capitatus. The LEO showed greater antibacterial activity than LEE. The LEO showed a broad spectrum of antibacterial activity and the Pseudomonas aeruginosa was the most sensitive bacteria.
    Matched MeSH terms: Staphylococcus aureus/drug effects
  4. Ahmad Zorin Sahalan, Nazahiyah Sulaiman, Nihayah Mohammed, Kaswandi Md. Ambia, Hing, Hian Lian
    MyJurnal
    Two species of plants, Andrographis paniculata and Euphorbia hirta were screened for antibacterial activities against three Gram positives and Gram negatives. The leaves from both plants were extracted by methanol extraction. The antibacterial activity was detected with spread plate well diffusion method. The extracts of both plants demonstrated inhibitory activity against both Gram negative and positives bacteria. Staphylococcus aureus, Bacillus subtilis, Streptococcus epidemidis, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa. The minimum inhibitory concentration (MIC determination using micro dilution method showed that the A/tic of A. paniculata for the tested bacteria were 1.56 mg/ml (Staph. aureus), 3.13 mg/ml (Bacillus subtilis), 3.13 mg/ml (Strept. epidemidis), 1.56 mg/ml (Escherichia cob), 12.50 mg/ml (Klebsiella pneumoniae) and 3.13 mg/ml (Pseudomonas aeruginosa) respectively. The MIC value for E. hirta was 6.25 mg/ml (Staph. aureus) and 3.13 mg/ml (Bacillus subtilis), 3.13 mg/ml (Strept. Epidemidis), 3.13 mg/ml (Pseudomonas aeruginosa),12.5 mg/ml (Escherichia coli), and 6.25 mg/ml (Klebsiella pneumoniae). Both plants represent a potential for pharmaceutical and agricultural applications and are worthy of further study.
    Matched MeSH terms: Staphylococcus aureus
  5. Leitgeb J, Schuster R, Yee BN, Chee PF, Harnoss JC, Starzengruber P, et al.
    BMC Surg, 2015 Jul 04;15:81.
    PMID: 26141495 DOI: 10.1186/s12893-015-0058-5
    BACKGROUND: A surgical glove will protect surgeons and patients only if the glove's integrity remains intact. However, several studies have demonstrated that undetected micro-perforations of surgical gloves are common. Because of the possibility of surgical glove puncture, an antimicrobial surgical glove was developed. The aim of this laboratory based experimental study was to assess the antibacterial efficacy of the interior chlorhexidine-gluconate (CHG)-coat of an antimicrobial synthetic polyisoprene surgical glove by using a standardized microbiological challenge.

    METHODS: Sixteen healthy adult participants donned one antimicrobial surgical glove and one non-antimicrobial surgical glove randomly allocated to their dominant and non-dominant hand following a crossover design. During a 2-h wear time, participants performed standardized finger and hand movements. Thereafter, the interior surface of excised fingers of the removed gloves was challenged with 8.00 log10 cfu/mL S. aureus (ATCC 6538) or K. pneumoniae (ATCC 4352), respectively. The main outcome measure was the viable mean log10 cfu counts of the two glove groups after 5 min contact with the interior glove's surface.

    RESULTS: When comparing an antimicrobial glove against an untreated reference glove after 2-h simulated use wear-time, a mean reduction factor of 6.24 log10 (S. aureus) and 6.22 log10 (K. pneumoniae) was achieved after 5 min contact.

    CONCLUSION: These results demonstrate that wearing antibacterial gloves on hands does not negatively impact their antibacterial activity after 2-h of wear. This may have a potential benefit for patient safety in case of glove puncture during surgical procedures.

    Matched MeSH terms: Staphylococcus aureus/drug effects*
  6. Katas H, Lim CS, Nor Azlan AYH, Buang F, Mh Busra MF
    Saudi Pharm J, 2019 Feb;27(2):283-292.
    PMID: 30766441 DOI: 10.1016/j.jsps.2018.11.010
    A simple, cost-effective, and environmentally friendly method is needed for synthesizing metal nanoparticles, including gold nanoparticles (AuNPs). In this study, AuNPs were synthesized with Lignosus rhinocerotis sclerotial extract (LRE) and chitosan (CS) as reducing and stabilizing agents, respectively. Different LRE concentrations from cold and hot water extraction (CWE and HWE, respectively) were used to reduce chloroauric acid (HAuCl4) to form AuNPs. Positively charged chitosan stabilized AuNPs (CS-AuNPs) mediated by LRE exhibited a surface plasmon resonance (SPR) band at 533 nm. The CS-AuNPs synthesized using CWE had a smaller particle size (49.5 ± 6.7-82.4 ± 28.0 nm) compared to that of the HWE samples (80.3 ± 23.4-125.3 ± 41.5 nm), depending on LRE concentration. FTIR results suggested protein and polysaccharides in LRE were the sources of reducing power, reducing gold ions to AuNPs. CS-AuNPs were mostly spherical with higher LRE concentrations, whereas some triangular, pentagonal, irregular, and rod shaped AuNPs were observed at lower LRE concentrations. CS-AuNPs mediated by LRE displayed effective antibacterial activity against gram-negative (Pseudomonas aeruginosa and Escherichia coli) and gram-positive bacteria (Staphylococcus aureus and Bacillus sp.). Thus, the biosynthesized AuNPs using LRE and chitosan provide opportunities for developing stable and eco-friendly nanoparticles with effective antibacterial properties.
    Matched MeSH terms: Staphylococcus aureus
  7. Tan YN, Ayob MK, Osman MA, Matthews KR
    Lett Appl Microbiol, 2011 Nov;53(5):509-17.
    PMID: 21848644 DOI: 10.1111/j.1472-765X.2011.03137.x
    The goal of this study was to determine inhibitory effect of palm kernel expeller (PKE) peptides of different degree of hydrolysis (DH %) against spore-forming bacteria Bacillus cereus, Bacillus circulans, Bacillus coagulans, Bacillus licheniformis, Bacillus megaterium, Bacillus pumilus, Bacillus stearothermophillus, Bacillus subtilis, Bacillus thuringiensis, Clostridium perfringens; and non-spore-forming bacteria Escherichia coli, Lisinibacillus sphaericus, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella Typhimurium and Staphylococcus aureus.
    Matched MeSH terms: Staphylococcus aureus/drug effects
  8. Ahmad Zorin Sahalan, Baharudin Omar, Aima Yusirah Mohamed, Jeffery, John
    MyJurnal
    Natural peptides in insect vectors played an important role in the control of
    pathogens. Musca domestica Linnaeus and Chrysomya megacephala Fabricius were
    two species of local fly chosen to detect presence of antimicrobial peptide substance.
    The screening of the antimicrobial activity was carried using a spectrophotometric
    method. Results were obtained much quicker and less laborious. The results showed
    larva hemolymph of M. domestica lysed Bacillus subtilis and two Gram negatives,
    Escherichia coli and Pseudomona. aeruginosa. The pupae hemolymph only lysed E.
    coli. Whereas, the hemolymph of C. megacephala larva showed bactericidal effect
    against both of the Gram positives tested, i.e. B. subtilis and Staph. aureus. and no
    effect was against the Gram negatives. The pupa showed lytic activity against Staph.
    aureus and P. aeruginosa. As a conclusion, the larva and pupa hemolymph of M.
    domestica and C. megacephala demonstrated antibacterial activity. However, larva
    hemolymph of M. domestica and C. megacephala has broader antibacterial activity
    against both Gram positive and negative bacteria.
    Matched MeSH terms: Staphylococcus aureus
  9. 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*
  10. Zainol MI, Mohd Yusoff K, Mohd Yusof MY
    PMID: 23758747 DOI: 10.1186/1472-6882-13-129
    Antibacterial activity of honey is mainly dependent on a combination of its peroxide activity and non-peroxide components. This study aims to investigate antibacterial activity of five varieties of Malaysian honey (three monofloral; acacia, gelam and pineapple, and two polyfloral; kelulut and tualang) against Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Pseudomonas aeruginosa.
    Matched MeSH terms: Staphylococcus aureus/drug effects; Staphylococcus aureus/growth & development
  11. Ali SM, Siddiqui R, Sagathevan KA, Khan NA
    Folia Microbiol (Praha), 2021 Apr;66(2):285-291.
    PMID: 33704690 DOI: 10.1007/s12223-021-00860-6
    The evolution of multiple-drug resistant bacteria is contributing to the global antimicrobial crisis, hence driving us to search for novel antimicrobial(s). Among animals, invertebrates represent up to 80% of all known species suggesting their wide distribution. Despite their ubiquitous and plentiful nature, they have been largely unexplored as potential source of antibacterials. In this study, we selected a broad range of invertebrates from terrestrial and marine environments and tested their lysates for antibacterial activity against methicillin-resistant Staphylococcus aereus (MRSA) and neuropathogenic Escherichia coli K1. Cockroaches, centipedes, tarantulas, prawns, lobster, and mud crabs showed antibacterial activity with selected lysates exhibiting more than 90% bactericidal effects. The red-headed centipede's hemolymph showed 90% and 50% bacteriostatic activity against MRSA and E. coli K1, respectively. Tarantula's body extracts exhibited antibacterial activity against MRSA and E. coli K1. Gut extracts of tiger prawn exhibited more than 90% bacteriostatic activity against both bacteria. The selected lobster and mud crab extract exhibited up to 90% growth inhibitory activity against MRSA. Overall, these results showed that selected invertebrates are an untapped source of broad-spectrum antibacterial activity and suggest the presence of biologically active molecules.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus
  12. Karunanidhi A, Ghaznavi-Rad E, Hamat RA, Pichika MR, Lung LTT, Mohd Fauzi F, et al.
    Biomed Res Int, 2018;2018:9845075.
    PMID: 30105271 DOI: 10.1155/2018/9845075
    The present study assessed the in vitro antibacterial and antibiofilm potential of hexane (ASHE) and dichloromethane (ASDE) extracts of Allium stipitatum (Persian shallot) against planktonic cells and biofilm structures of clinically significant antibiotic resistant pathogens, with a special emphasis on methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), and emerging pathogens, Acinetobacter baumannii and Stenotrophomonas maltophilia. Antibacterial activities were determined through disk diffusion, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), time-kill kinetics, and electron microscopy. Antibiofilm activity was assessed by XTT [2,3-bis(2-methoxy-4-nitro-5-sulfo-phenyl)-2H-tetrazolium-5-carboxanilide] reduction assay and by confocal laser scanning microscopy (CLSM). The zone of inhibition ranged from 13 to 33 mm, while the MICs and MBCs ranged from 16 to 1024 μg mL-1. Both ASHE and ASDE completely eradicated overnight cultures of the test microorganisms, including antibiotic resistant strains. Time-kill studies showed that the extracts were strongly bactericidal against planktonic cultures of S. aureus, MRSA, Acinetobacter baumannii, and S. maltophilia as early as 4 hours postinoculation (hpi). ASHE and ASDE were shown to inhibit preformed biofilms of the four biofilm phenotypes tested. Our results demonstrate the potential therapeutic application of ASHE and ASDE to inhibit the growth of gram-positive and gram-negative biofilms of clinical significance and warrant further investigation of the potential of A. stipitatum bulbs against biofilm-related drug resistance.
    Matched MeSH terms: Staphylococcus aureus; Methicillin-Resistant Staphylococcus aureus/drug effects*
  13. Lum CL, Jeyanthi S, Prepageran N, Vadivelu J, Raman R
    J Laryngol Otol, 2009 Apr;123(4):375-8.
    PMID: 18694532 DOI: 10.1017/S0022215108003307
    To assess the antibacterial and antifungal properties of human cerumen by studying its effect on the growth of Staphylococcus aureus, Esherichia coli, Pseudomonas aeruginosa and Candida albicans.
    Matched MeSH terms: Staphylococcus aureus/growth & development*
  14. Nordin ML, Othman AA, Kadir AA, Shaari R, Osman AY, Mohamed M
    Vet World, 2019;12(2):236-242.
    PMID: 31040564 DOI: 10.14202/vetworld.2019.236-242
    Background and Aim: The increasing prevalence of drug resistance eventually leads scientist to discover new drugs that could solve the problem. Since ancient immemorial times, medicinal plants generally known as herbs were widely used in every culture throughout the world. In fact, currently up to 70,000 plant species have been screened for biological activities and about 70% ends up for commercialization. Therefore, this study was aimed to evaluate the potential cytotoxic and antibacterial effect of Syzygium polyanthum leaves which are local Malaysia plants, against 4T1 and MCF-7 mammary carcinoma cells, respectively, and also against bacteria causing mastitis in cows.

    Materials and Methods: The cytotoxic effect of hydromethanolic extract of S. polyanthum against 4T1 and MCF-7 mammary carcinoma cells was evaluated using 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The cells were treated with the concentration of extracts ranging from 15.63 µg/mL to 1000 µg/ml for 72 h, and the percentage of cell survivability was determined based on minimum concentration that was able to allow at least 50% growth of cancer cells (IC50) after 72 h. The antibacterial activity was tested against common bacteria causing mastitis in cow. The bacteria were isolated from milk samples. The antibacterial activity of the extract was determined by disk diffusion method and susceptibility test based on minimum inhibitory concentration (MIC).

    Results: Staphylococcus aureus, Staphylococcus hyicus, and Staphylococcus intermedius were isolated from the milk samples that positive for mastitis. The MIC values range from 7.12 mm to 13.5 mm. The extract exhibits the widest zone of inhibition (13.5±0.20 mm) at 1000 mg/ml of concentrations. The extract relatively has low cytotoxicity effect against 4T1 and MCF-7 cells with IC50 values ranging from 672.57±59.42 and 126.05±50.89 µg/ml, respectively.

    Conclusion: S. polyanthum exerts weak antibacterial activity and cytotoxic effect to mammary carcinoma cells. The extract does not toxic to cells. However, further study is recommended, especially, this plant should be tested for in vivo.

    Matched MeSH terms: Staphylococcus aureus
  15. 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: Staphylococcus aureus
  16. Gomaa MN, Soliman K, Ayesh A, Abd El-Wahed A, Hamza Z, Mansour HM, et al.
    Nat Prod Res, 2016;30(6):729-34.
    PMID: 26186031 DOI: 10.1080/14786419.2015.1040991
    The marine soft corals Sarcophyton trocheliophorum crude extracts possessed antimicrobial activity towards pathogenic bacterial strains, i.e. Bacillus cereus, Salmonella typhi, Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. Bioassay-guided fractionation indicated that the antimicrobial effect was due to the presence of terpenoid bioactive derivatives. Further biological assays of the n-hexane fractions were carried out using turbidity assay, inhibition zone assay and minimum inhibitory concentration for investigating the growth-inhibition effect towards the Gram-positive and Gram-negative bacteria. The fractions were screened and the structure of the isolated compound was justified by interpretation of the spectroscopic data, mainly mass spectrometry (GC-MS). The structure was assigned as (5S)-3-[(3E,5S)-5-hydroxy-3-hepten-6-yn-1-yl]-5-methyl-2(5H)-furanone and was effective at concentrations as low as 0.20 mg/mL. The above findings, in the course of our ongoing research on marine products, may implicate that the profound anti-microbial activity of the S. trocheliophorum soft corals, inhabiting the red sea reefs, is attributed to the presence of growth-inhibiting secondary metabolites mainly terpenoids.
    Matched MeSH terms: Staphylococcus aureus/drug effects
  17. Hossan MS, Jindal H, Maisha S, Samudi Raju C, Devi Sekaran S, Nissapatorn V, et al.
    Pharm Biol, 2018 Dec;56(1):201-208.
    PMID: 29529970 DOI: 10.1080/13880209.2018.1446030
    CONTEXT: The resistance of bacteria to antibiotics is raising serious concern globally. Asian medicinal plants could improve the current treatment strategies for bacterial infections. The antibacterial properties of medicinal plants used by the Khyang tribe in Bangladesh have not been investigated.

    OBJECTIVE: The present study examines the antibacterial properties of 18 medicinal plants used by the Khyang tribe in day-to-day practice against human pathogenic bacteria.

    MATERIALS AND METHODS: Leaves, bark, fruits, seeds, roots and rhizomes from collected plants were successively extracted with hexane, ethyl acetate and ethanol. The corresponding 54 extracts were tested against six human pathogenic bacteria by broth microdilution assay. The antibacterial mode of actions of phytoconstituents and their synergistic effect with vancomycin and cefotaxime towards MRSA was determined by time-killing assay and synergistic interaction assay, respectively.

    RESULTS AND DISCUSSION: Hexane extract of bark of Cinnamomum cassia (L.) J. Presl. (Lauraceae) inhibited the growth of MRSA, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Acinetobacter baumannii with MIC values below 100 µg/mL. From this plant, cinnamaldehyde evoked at 4 × MIC in 1 h an irreversible decrease of MRSA count Log10 (CFU/mL) from 6 to 0, and was synergistic with vancomycin for MRSA with fractional inhibitory concentration index of 0.3.

    CONCLUSIONS: Our study provides evidence that the medicinal plants in Bangladesh have high potential to improve the current treatment strategies for bacterial infection.

    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/drug effects; Methicillin-Resistant Staphylococcus aureus/growth & development
  18. Nor Hazliana Harun, Rabiatul Basria S.M.N. Mydin, Khairul Anuar Shariff, Nur Adila Rosdi, Davamunisvari Rames
    MyJurnal
    Introduction: This study aims to investigate different residue sizes of β-tricalcium phosphate (β-TCP) micro-granules as carriers to assess antibacterial activity and drug-control release behavior of ampicillin (AMP-) and antimycotic (AMC-). Incorporation of antibiotic into the β-TCP micro-granules and it sustain release behavior could be used as alternative solution to reduce the risk of osteomyelitis and bone infections risks. Methods: Three different residue sizes (less than 300 µm, 300 µm and 600 µm) were prepared and coated with antibiotics solution (20 µg/µl of ampi- cillin and 100X antimycotic solution) by using two methods; dip and stream coating. After 72 h, 1.5 mL of distilled water was added to the treated (β-TCP) micro-granules at two different pH value (5.0 and 7.4). The extracted solution was further analyzed by Kirby Bauer disc diffusion test and spectrophotometer assay. Results: The solution con- taining AMC-(β-TCP) micro-granules with the size of 300 µm residue produced the largest inhibition zones against Escherichia coli (E. coli). All residue sizes coated with AMP- showed no antibacterial activity against both strains; Staphylococcus aureus (S. aureus) and E.coli. Additionally, the release behavior of AMC-(β-TCP) micro-granules was found not depending on the pH, but on the size of residue. Complete drug release was rapidly observed within 48
    h. Conclusion: Based on this findings, it showed AMC-(β-TCP) micro-granules had an antibacterial activity against Gram-negative strain. Specifically, it can reduced the growth rate of E. coli and the rapid release behavior of AMC- (β-TCP) micro-granules help in minimizing the risk-infections in early stage of implantation.
    Matched MeSH terms: Staphylococcus aureus
  19. Aruldass CA, Masalamany SRL, Venil CK, Ahmad WA
    Environ Sci Pollut Res Int, 2018 Feb;25(6):5164-5180.
    PMID: 28361404 DOI: 10.1007/s11356-017-8855-2
    Violacein, violet pigment produced by Chromobacterium violaceum, has attracted much attention recently due to its pharmacological properties including antibacterial activity. The present study investigated possible antibacterial mode of action of violacein from C. violaceum UTM5 against Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) strains. Violet fraction was obtained by cultivating C. violaceum UTM5 in liquid pineapple waste medium, extracted, and fractionated using ethyl acetate and vacuum liquid chromatography technique. Violacein was quantified as major compound in violet fraction using HPLC analysis. Violet fraction displayed bacteriostatic activity against S. aureus ATCC 29213 and methicillin-resistant S. aureus ATCC 43300 with minimum inhibitory concentration (MIC) of 3.9 μg/mL. Fluorescence dyes for membrane damage and scanning electron microscopic analysis confirmed the inhibitory effect by disruption on membrane integrity, morphological alternations, and rupture of the cell membranes of both strains. Transmission electron microscopic analysis showed membrane damage, mesosome formation, and leakage of intracellular constituents of both bacterial strains. Mode of action of violet fraction on the cell membrane integrity of both strains was shown by release of protein, K+, and extracellular adenosine 5'-triphosphate (ATP) with 110.5 μg/mL, 2.34 μg/mL, and 87.24 ng/μL, respectively, at 48 h of incubation. Violet fraction was toxic to human embryonic kidney (HEK293) and human fetal lung fibroblast (IMR90) cell lines with LC50 value of 0.998 ± 0.058 and 0.387 ± 0.002 μg/mL, respectively. Thus, violet fraction showed a strong antibacterial property by disrupting the membrane integrity of S. aureus and MRSA strains. This is the first report on the possible mode of antibacterial action of violet fraction from C. violaceum UTM5 on S. aureus and MRSA strains.
    Matched MeSH terms: Staphylococcus aureus/drug effects*; Staphylococcus aureus/ultrastructure; Methicillin-Resistant Staphylococcus aureus/drug effects*; Methicillin-Resistant Staphylococcus aureus/ultrastructure
  20. Jiang L, Huang P, Ren B, Song Z, Zhu G, He W, et al.
    Appl Microbiol Biotechnol, 2021 Jun;105(12):4975-4986.
    PMID: 34146138 DOI: 10.1007/s00253-021-11226-w
    Marine microbes provide an important resource to discover new chemical compounds with biological activities beneficial to drug discovery. In our study, two new polyene macrolides, pyranpolyenolides A (1) and B (2), and one new natural cyclic peptide (9), together with two known polyenes (7 and 8) and three known cyclic peptides (10-12), were isolated from a culture of the marine Streptomyces sp. MS110128. In addition, four new polyene macrolides, pyranpolyenolides C-F (3-6), were identified as olefin geometric isomers that were most likely produced by photochemical conversion during the cultivation or isolation procedures. The pyranpolyenolides are 32-membered macrolides endowed with a conjugated tetraene and several pairs of 1,3-dihydroxyl groups. Pyranpolyenolides that contain a hydropyran group have not been previously reported. Four cyclic peptides (9-12) showed significant activities against Bacillus subtilis, Staphylococcus aureus, and methicillin-resistant S. aureus with supporting MIC values ranging from 0.025 to 1.25 μg/mL. These cyclic peptides containing piperazic moieties showed moderate activities with MIC values of 12.5 μg/mL against Bacille Calmette Guerin (BCG), an attenuated form of the bovine. Additionally, cyclic peptide 12 showed moderate antifungal activity against Candida albicans with an MIC value of 12.5 μg/mL. KEY POINTS: • Discovery of new polyenes and cyclic peptides from a marine-derived Actinomycete. • Cyclic peptides containing piperazic moieties exhibited good antibacterial activity.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus*
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