Displaying publications 41 - 60 of 609 in total

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  1. Fulltext Rapid detection of methicillin-resistant Staphylococcus aureus by a newly developed dry reagent-based polymerase chain reaction assay
    Al-Talib H, Yean CY, Al-Khateeb A, Hasan H, Ravichandran M
    J Microbiol Immunol Infect, 2014 Dec;47(6):484-90.
    PMID: 23927820 DOI: 10.1016/j.jmii.2013.06.004
    Methicillin-resistant Staphylococcus aureus (MRSA) is a major pathogen responsible for significant numbers of nosocomial and community-acquired infections worldwide. Molecular diagnosis for MRSA nasal carriers is increasingly important for rapid detection and screening of MRSA colonization because the conventional methods are time consuming and labor intensive. However, conventional polymerase chain reaction (PCR) tests still require cold-chain storage as well as trained personnel, which makes them unsuitable for rapid high-throughput analysis. The aim of this study was to develop a thermostabilized PCR assay for MRSA in a ready-to-use form that requires no cold chain.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/genetics; Methicillin-Resistant Staphylococcus aureus/isolation & purification*
  2. 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*
  3. Comparative evaluation of five culture media with triplex PCR assay for detection of methicillin-resistant Staphylococcus aureus
    Al-Talib H, Yean CY, Al-khateeb A, Singh KK, Hasan H, Al-Jashamy K, et al.
    Curr Microbiol, 2010 Jul;61(1):1-6.
    PMID: 20033170 DOI: 10.1007/s00284-009-9567-8
    The emergence of methicillin-resistant Staphylococcus aureus (MRSA) is responsible for nosocomial and community-acquired infections. Hence, rapid and accurate laboratory diagnosis of MRSA is a vital constituent of control measures. The present study evaluated five different methods for the identification of MRSA. A total of 207 S. aureus clinical isolates that consisted of 89 MRSA and 118 methicillin-susceptible S. aureus (MSSA) strains confirmed by PCR were tested. MRSA strains were evaluated by five different methods: chromogenic MRSA agar (CMRSA), oxacillin resistance screening agar base (ORSAB), mannitol salt oxacillin agar (MSO), mannitol salt cefoxitin agar with two different concentrations of cefoxitin [4 microg/ml (MSC-4) and 6 microg/ml (MSC-6)]. The results of the different methods were compared to mecA PCR as the gold standard. MSC-6 showed only six false-positive MRSA in comparison with PCR. The sensitivities and specificities of MSC-6, MSC-4, MSO-4, ORSAB, and CMRSA were as follows: 98.9/94.9%, 100/83.1%, 89.9/87.3%, 97.8/96.6%, and 95.5/94.9%, respectively. In comparison with PCR, it was found that both MSC-6 and ORSAB were relatively the least expensive screening tests ($0.70 and $1.00, respectively). In conclusion, all methods were comparable, but MSC-6 was the least expensive medium for MRSA screening.
    Matched MeSH terms: Staphylococcus aureus/drug effects; Staphylococcus aureus/genetics; Staphylococcus aureus/growth & development; Staphylococcus aureus/isolation & purification; Methicillin-Resistant Staphylococcus aureus/drug effects; Methicillin-Resistant Staphylococcus aureus/growth & development; Methicillin-Resistant Staphylococcus aureus/isolation & purification*
  4. Fatal necrotizing pneumonia caused by Panton-Valentine leukocidin-producing hospital-acquired Staphylococcus aureus: a case report
    Al-Talib H, Hasan H, Yean CY, Al-Ashwal SM, Ravichandran M
    Jpn J Infect Dis, 2011;64(1):58-60.
    PMID: 21266757
    Panton-Valentine leukocidin (PVL) is a cytotoxin which causes leukocyte destruction and tissue necrosis. Although it is produced by fewer than 5% of Staphylococcus aureus strains, PVL-producing S. aureus is emerging as a serious problem worldwide. There has been a marked increase in the incidence of necrotizing lung infections with a very high mortality associated with these strains. This report describes a fatal case of hospital-acquired necrotizing pneumonia caused by PVL-positive methicillin-susceptible S. aureus in a patient with a brain tumor.
    Matched MeSH terms: Staphylococcus aureus/drug effects; Staphylococcus aureus/metabolism*; Staphylococcus aureus/pathogenicity
  5. Fulltext A pentaplex PCR assay for the rapid detection of methicillin-resistant Staphylococcus aureus and Panton-Valentine Leucocidin
    Al-Talib H, Yean CY, Al-Khateeb A, Hassan H, Singh KK, Al-Jashamy K, et al.
    BMC Microbiol, 2009;9:113.
    PMID: 19476638 DOI: 10.1186/1471-2180-9-113
    Staphylococcus aureus is a major human pathogen, especially methicillin-resistant S. aureus (MRSA), which causes a wide range of hospital and community-acquired infections worldwide. Conventional testing for detection of MRSA takes 2-5 days to yield complete information of the organism and its antibiotic sensitivity pattern.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/genetics; Methicillin-Resistant Staphylococcus aureus/isolation & purification*
  6. Fulltext Methicillin-resistant Staphylococcus aureus nosocomial infection trends in Hospital Universiti Sains Malaysia during 2002-2007
    Al-Talib HI, Yean CY, Al-Jashamy K, Hasan H
    Ann Saudi Med, 2010 Sep-Oct;30(5):358-63.
    PMID: 20697171 DOI: 10.4103/0256-4947.67077
    Methicillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen that causes severe morbidity and mortality in many hospitals worldwide. The aim of the present study was to assess the burden of MRSA nosocomial infection, its association with factors of interest, and its antimicrobial susceptibility.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus*
  7. Pluronic-F127 composite film loaded with erythromycin for wound application: formulation, physicomechanical and in vitro evaluations
    Alavi T, Rezvanian M, Ahmad N, Mohamad N, Ng SF
    Drug Deliv Transl Res, 2019 04;9(2):508-519.
    PMID: 29181832 DOI: 10.1007/s13346-017-0450-z
    Composite film dressings composed of pluronic F127 (PL)-pectin (PC) and pluronic (PL) F127-gelatin (GL) were investigated as potential drug delivery system for wound healing. Composite films were solvent cast by blending PL with PC or GL in different ratios using glycerol (2.5%) as plasticizer. Erythromycin (ER) (0.1%) was incorporated in films as model hydrophobic antibiotic. The optimized composite films were characterized for physical appearance, morphology, mechanical profile, and thermal behavior. In addition, drug release, antibacterial activity, and cytocompatibility of the films were investigated to assess their potential as drug delivery system. The composite films exhibited excellent wound dressing characters in terms of appearance, stability, and mechanical profile. Moreover, ER-loaded composite films released ER in controlled manner, exhibited antibacterial activity against Staphylococcus aureus, and were non-toxic to human skin fibroblast. These findings demonstrate that these composite films hold the potential to be formulated as antibacterial wound dressing.
    Matched MeSH terms: Staphylococcus aureus/drug effects; Staphylococcus aureus/growth & development
  8. Development, characterization and pharmacokinetics of mupirocin-loaded nanostructured lipid carriers (NLCs) for intravascular administration
    Alcantara KP, Zulfakar MH, Castillo AL
    Int J Pharm, 2019 Nov 25;571:118705.
    PMID: 31536765 DOI: 10.1016/j.ijpharm.2019.118705
    Mupirocin is a promising broad-spectrum antibiotic that is effective in treating MRSA infections. However, due to its rapid elimination and hydrolysis following injection and high protein binding, current therapeutic use is limited to topical administration. Nanotechnology-driven innovations provide hope for patients and practitioners in overcoming the problem of drug degradation by encapsulation. The objective of this research is to develop and characterize Mupirocin-Loaded Nanostructured Lipid Carriers (M-NLC) for intravascular administration. The MNLC was produced by a combination of high shear homogenization and high pressure homogenization of solid (cetyl palmitate) and liquid (caprylic/caprylic acid) biocompatible lipids in 5 different ratios. The mean particle size, polydispersity index (PDI) and the zeta potential (ZP) of the MNLC formulations were between 99.8 and 235 nm, PDI lower than 0.164, ZP from -25.96 to -19.53 and pH ranging from 6.28-6.49. The MNLC formulation also enhances the anti-bacterial activity of mupirocin. All formulation showed sustained drug release and good physical characteristics for three months storage under 25 °C. It also revealed that the MNLC 1 is safe at 250 mg/kg dose in rats. The MNLC 1 also showed a significant increase in plasma concentration in rabbits following IV administration thus, demonstrating an enhancement on its pharmacokinetic profile as compared to free mupirocin.
    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus
  9. Fulltext DNA fingerprinting of methicillin-resistant Staphylococcus aureus (MRSA) by pulsed-field gel electrophoresis (PFGE) in a teaching hospital in Malaysia
    Alfizah H, Norazah A, Nordiah AJ, Lim VKE
    Med J Malaysia, 2002 Sep;57(3):319-28.
    PMID: 12440272 MyJurnal
    Methicillin-resistant Staphylococcus aureus (MRSA) has been prevalent in our hospital over the last three years. Differentiation among MRSA strains by DNA typing in addition to antibiotic resistance pattern surveillance is crucial in order to implement infection control measures. The aim of this study was to characterize MRSA isolates from patients admitted to Hospital Universiti Kebangsaan Malaysia (HUKM) by phenotypic (analyses of antibiotic susceptibility pattern) and genotypic (PFGE) techniques to determine the genetic relatedness of the MRSA involved and to identify endemic clonal profiles of MRSA circulating in HUKM. Seventy one MRSA strains collected between January to March 2000 from patients from various wards in HUKM were tested for antimicrobial resistance and typed by pulsed-field gel electrophoresis (PFGE). Four major types of PFGE patterns were identified (A, B, C and D) among MRSA strains. Two predominant PFGE types were recognised, Type A (59.2%) and Type B (33.8%). Most of these strains were isolated from ICU, Surgical wards and Medical wards. MRSA strains with different PFGE patterns appeared to be widespread among wards. Strains with the same antibiotype could be of different PFGE types. Most of isolates were resistant to ciprofloxacin, erythromycin, gentamicin and penicillin. One isolate with a unique PFGE pattern Type D and susceptible to gentamicin was identified as a different clone. Some isolates obtained from the same patient showed different PFGE subtypes suggesting that these patients were infected/colonized with multiple MRSA strains. PFGE analysis suggests that MRSA strains with different PFGE types was propagated within our hospital. The relationship between antibiotic susceptibility and PFGE patterns was independent. The ability of PFGE technique in differentiating our MRSA strains make it a method of choice for investigating the source, transmission and spread of nosocomial MRSA infection, and thus an appropriate control programme can be implemented to prevent the spread of MRSA infection.
    Matched MeSH terms: Staphylococcus aureus/genetics*
  10. Prominent bactericidal characteristics of silver-copper nanocomposites produced via pulse laser ablation
    Alhajj M, Aziz MSA, Huyop F, Salim AA, Sharma S, Ghoshal SK
    Biomater Adv, 2022 Nov;142:213136.
    PMID: 36206587 DOI: 10.1016/j.bioadv.2022.213136
    This paper reports the characterization and antibacterial performance evaluation of some spherical and stable crystalline silver (Ag)/copper (Cu) nanocomposites (Ag-CuNCs) prepared in deionized water (DIW) using pulse laser ablation in liquid (PLAL) method. The influence of various laser fluences (LFs) on the structural, morphological, optical and antibacterial properties of these NCs were determined. The UV-Vis absorbance of these NCs at 403 nm and 595 nm was gradually increased accompanied by a blue shift. XRD patterns disclosed the nucleation of highly crystalline Ag-CuNCs with their face centered cubic lattice structure. TEM images showed the existence of spherical NCs with size range of 3-20 nm and lattice fringe spacing of approximately 0.145 nm. EDX profiles of Ag-CuNCs indicated their high purity. The antibacterial effectiveness of the Ag-CuNCs was evaluated by the inhibition zone diameter (IZD) and optical density (OD600) tests against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria. The proposed NCs revealed the IZD values in the range of 22-26 mm and 20-25 mm when tested against E. coli and S. aureus bacteria, respectively. The Ag-CuNCs prepared at LF of 14.15 J/cm2 revealed the best bactericidal activity. It is established that by controlling the laser fluence the bactericidal effectiveness of the Ag-CuNCs can be tuned.
    Matched MeSH terms: Staphylococcus aureus
  11. Comparison of MALDI-TOF mass spectrometry with phenotypic methods for identification and characterization of Staphylococcus aureus causing mastitis
    Alharbi A, Al-Dubaib M, Elhassan MAS, Elbehiry A
    Trop Biomed, 2021 Jun 01;38(2):9-24.
    PMID: 33973568 DOI: 10.47665/tb.38.2.032
    The emergence of methicillin-resistant Staphylococcus aureus (MRSA) infection is one of the greatest threats to both animal and human health. Our investigation was aimed to identify and differentiate between MRSA and methicillin-sensitive Staphylococcus aureus (MSSA) recovered from mastitic milk using MALDI-TOF mass spectrometry compared with phenotypic methods and studying their susceptibility to various antibiotics. Four hundred milk samples from mastitic animals (cows, sheep, goats, and dromedary camels) were investigated. Phenotypic identification of S. aureus was made through MASTASAPH Latex test, STAPH ID 32, and Vitek 2 system. The proteomic characterization of S. aureus was done by MBT. The Kirby Bauer method was accomplished to detect the resistance of S. aureus strains to antibiotics. The results of the MASTASAPH Latex test, revealed that 54 (46%) were recognized as S. aureus. All S. aureus isolates were identified by MBT with a score of more or equal 2.00. Several peaks were identified in the mass of 4590 Da, 4863 Da, and 4938 Da for MSSA and in the mass of 2636 Da and 3009 Da for MRSA. The MSP dendrogram demonstrated that the S. aureus isolates were classified into one group with a distance level of less or equal 400. The percentage of S. aureus resistance against carbenicillin, erythromycin and kanamycin was 94.4%, 38.88%, and 33.33%, respectively. In conclusion, S. aureus bacteria are among the key triggers for mastitis in Saudi Arabia. MBT is reported to be not only the rapid tool to identify S. aureus but also able to discriminate MRSA from MSSA.
    Matched MeSH terms: Staphylococcus aureus; Methicillin-Resistant Staphylococcus aureus
  12. Fulltext Genomic analysis of methicillin-resistant Staphylococcus aureus strain SO-1977 from Sudan
    Ali MS, Isa NM, Abedelrhman FM, Alyas TB, Mohammed SE, Ahmed AE, et al.
    BMC Microbiol, 2019 06 11;19(1):126.
    PMID: 31185900 DOI: 10.1186/s12866-019-1470-2
    BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is known as a leading cause of morbidity and mortality. Investigation of the MRSA's virulence and resistance mechanisms is a continuing concern toward controlling such burdens through using high throughput whole Genome Sequencing (WGS) and molecular diagnostic assays. The objective of the present study is to perform whole-genome sequencing of MRSA isolated from Sudan using Illumina Next Generation Sequencing (NGS) platform.

    RESULTS: The genome of MRSA strain SO-1977 consists of 2,827,644 bp with 32.8% G + C, 59 RNAs and 2629 predicted coding sequences (CDSs). The genome has 26 systems, one of which is the major class in the disease virulence and defence. A total of 83 genes were annotated to virulence disease and defence category some of these genes coding as functional proteins. Based on genome analysis, it is speculated that the SO-1977 strain has resistant genes to Teicoplanin, Fluoroquinolones, Quinolone, Cephamycins, Tetracycline, Acriflavin and Carbapenems. The results revealed that the SO-1977, strain isolated from Sudan has a wide range of antibiotic resistance compared to related strains.

    CONCLUSION: The study reports for the first time the whole genome sequence of Sudan MRSA isolates. The release of the genome sequence of the strain SO-1977 will avail MRSA in public databases for further investigations on the evolution of resistant mechanism and dissemination of the -resistant genes of MRSA.

    Matched MeSH terms: Methicillin-Resistant Staphylococcus aureus/genetics*; Methicillin-Resistant Staphylococcus aureus/isolation & purification
  13. Sodium carboxymethyl cellulose hydrogels containing reduced graphene oxide (rGO) as a functional antibiofilm wound dressing
    Ali NH, Amin MCIM, Ng SF
    J Biomater Sci Polym Ed, 2019 06;30(8):629-645.
    PMID: 30896336 DOI: 10.1080/09205063.2019.1595892
    Biofilms comprise bacteria attached to wound surfaces and are major contributors to non-healing wounds. It was found that the increased resistance of biofilms to antibiotics allows wound infections to persist chronically in spite of antibiotic therapy. In this study, the reduced form of graphene oxide (rGO) was explored as plausible antibiofilm agents. The rGO was synthesized via reducing the functional groups of GO. Then, rGO were characterized using zetasizer, X-ray photoelectron spectroscopy, UV-Vis spectroscopy and FESEM. The rGO were then formulated into sodium carboxymethyl cellulose (NaCMC) hydrogels to form rGO hydrogel and tested for antibiofilm activities in vitro using XTT test, and in vivo biofilm formation assay using nematodes C. elegans. Reduced GO hydrogel was successfully formed by reducing the functional groups of GO, and a reduction of up to 95% of functional groups was confirmed with X-ray photoelectron spectroscopy analysis. XTT tests confirmed that rGO hydrogels reduced biofilm formation by S. aureus (81-84%) and P. aeruginosa (50-62%). Fluorescence intensity also confirmed that rGO hydrogel can inhibit biofilm bacteria in C. elegans experiments. This study implied that rGO hydrogel is an effective antibiofilm agent for infected wounds.
    Matched MeSH terms: Staphylococcus aureus/drug effects
  14. Identification and characterization of antibacterial compound(s) of cockroaches (Periplaneta americana)
    Ali SM, Siddiqui R, Ong SK, Shah MR, Anwar A, Heard PJ, et al.
    Appl Microbiol Biotechnol, 2017 Jan;101(1):253-286.
    PMID: 27743045 DOI: 10.1007/s00253-016-7872-2
    Infectious diseases remain a significant threat to human health, contributing to more than 17 million deaths, annually. With the worsening trends of drug resistance, there is a need for newer and more powerful antimicrobial agents. We hypothesized that animals living in polluted environments are potential sources of antimicrobials. Under polluted milieus, organisms such as cockroaches encounter different types of microbes, including superbugs. Such creatures survive the onslaught of superbugs and are able to ward off disease by producing antimicrobial substances. Here, we characterized antibacterial properties in extracts of various body organs of cockroaches (Periplaneta americana) and showed potent antibacterial activity in crude brain extract against methicillin-resistant Staphylococcus aureus and neuropathogenic Escherichia coli K1. The size-exclusion spin columns revealed that the active compound(s) are less than 10 kDa in molecular mass. Using cytotoxicity assays, it was observed that pre-treatment of bacteria with lysates inhibited bacteria-mediated host cell cytotoxicity. Using spectra obtained with LC-MS on Agilent 1290 infinity liquid chromatograph, coupled with an Agilent 6460 triple quadruple mass spectrometer, tissues lysates were analysed. Among hundreds of compounds, only a few homologous compounds were identified that contained the isoquinoline group, chromene derivatives, thiazine groups, imidazoles, pyrrole-containing analogs, sulfonamides, furanones, and flavanones and known to possess broad-spectrum antimicrobial properties and anti-inflammatory, anti-tumour, and analgesic properties. Further identification, characterization, and functional studies using individual compounds can act as a breakthrough in developing novel therapeutics against various pathogens including superbugs.
    Matched MeSH terms: Staphylococcus aureus/drug effects
  15. Antibacterial activity of selected invertebrate species
    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
  16. Fulltext Fever with intradialytic pelvic pain: a case of iliopsoas abscess complicated with Methicillin-sensitive Staphylococcus Aureus bacteraemia in an end stage renal failure patient
    Alif Adlan MT, Wan Mohd Rasis WA, Mohd Ramadhan MD
    Med J Malaysia, 2016 04;71(2):72-3.
    PMID: 27326946 MyJurnal
    Staphylococcus Aureus is a Gram-positive cocci bacteria which had been found to be the causative organism in over 88% of patients with primary iliopsoas abscess. We report the case of a 53-year-old diabetic woman with end-stage renal failure diagnosed with left iliopsoas abscess with a catheter-related infection. Computed tomogram (CT) of abdomen and pelvis revealed hypodense lesions of left psoas, iliacus and quadratus lumborum suggestive of psoas abscesses. In addition, osteomyelitis changes at left sacroiliac and hip joint were seen. At surgery, she was found to have abscess at the posterior psoas muscle where she underwent open surgery drainage and percutaneous drain was inserted. A high index of suspicion of iliopsoas abscess should be maintained among haemodialysis patients presenting with intradialytic pelvic and hip pain and treated with optimal antibiotics therapy with appropriate surgical intervention.
    Matched MeSH terms: Staphylococcus aureus/isolation & purification*
  17. Fulltext Antimicrobial activities of three different seed extracts of Lansium varieties
    Alimon, H, Abdullah Sani, A., Syed Abdul Azziz, S. S., Daud, N., Mohd Arriffin, N., Mhd Bakri, Y.
    Pertanika Journal of Science & Technology, 2014;22(2):529-540.
    MyJurnal
    Lansium domesticum Corr. is a fruit tree of the Meliaceae family, which is commonly found in SouthEast Asia with a wide range of varieties. This study investigated three varieties of L. domesticum; Duku, Langsat and Dokong for the phytochemical screening and antimicrobial activity. Seeds from the matured fruits were extracted using hexane, methanol and water. The crude extracts were screened for antimicrobial activities toward three bacteria, namely, Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus aureus. The findings showed that Langsat seed extracts contained more groups of compounds compared with the other two varieties, and its methanol extract demonstrated the highest inhibition zones against the three bacteria. The crude methanol extract of Duku seeds showed inhibition zones only towards Bacillus subtilis at a high concentration (1.0 mgL-1), whilst the seed extracts of Dokong showed no inhibition zones towards any of the tested bacteria.
    Matched MeSH terms: Staphylococcus aureus
  18. Superhydrophobic nanocarbon-based membrane with antibacterial characteristics
    Aljumaily MM, Alsaadi MA, Binti Hashim NA, Mjalli FS, Alsalhy QF, Khan AL, et al.
    Biotechnol Prog, 2020 05;36(3):e2963.
    PMID: 31943942 DOI: 10.1002/btpr.2963
    To overcome the biofouling challenge which faces membrane water treatment processed, the novel superhydrophobic carbon nanomaterials impregnated on/powder activated carbon (CNMs/PAC) was utilized to successfully design prepare an antimicrobial membrane. The research was conducted following a systematic statistical design of experiments technique considering various parameters of composite membrane fabrication. The impact of these parameters of composite membrane on Staphylococcus aureus growth was investigated. The bacteria growth was analyzed through spectrophotometer and SEM. The effect of CNMs' hydrophobicity on the bacterial colonies revealed a decrease in the abundance of bacterial colonies and an alteration in structure with increasing the hydrophobicity. The results revealed that the optimum preparative conditions for carbon loading CNMs/PAC was 363.04 mg with a polymer concentration of 22.64 g/100 g, and a casting knife thickness of 133.91 μm. These conditions have resulted in decreasing the number of bacteria colonies to about 7.56 CFU. Our results provided a strong evidence on the antibacterial effect and consequently on the antibiofouling potential of CNMs/PAC in membrane.
    Matched MeSH terms: Staphylococcus aureus/drug effects; Staphylococcus aureus/pathogenicity
  19. Evaluation of morphological changes of Staphylococcus aureus and Escherichia coli induced with the antimicrobial peptide AN5-1
    Alkotaini B, Anuar N, Kadhum AA
    Appl Biochem Biotechnol, 2015 Feb;175(4):1868-78.
    PMID: 25427593 DOI: 10.1007/s12010-014-1410-4
    The mechanisms of action of AN5-1 against Gram-negative and Gram-positive bacteria were investigated by evaluations of the intracellular content leakage and by microscopic observations of the treated cells. Escherichia coli and Staphylococcus aureus were used for this investigation. Measurements of DNA, RNA, proteins, and β-galactosidase were taken, and the results showed a significant increase in the cultivation media after treatment with AN5-1 compared with the untreated cells. The morphological changes of treated cells were shown using transmission electron microscopy (TEM) and atomic force microscopy (AFM). The observations showed that AN5-1 acts against E. coli and against S. aureus in similar ways, by targeting the cell wall, causing disruptions; at a high concentration (80 AU/ml), these disruptions led to cell lysis. The 3D AFM imaging system showed that at a low concentration of 20 AU/ml, the effect of AN5-1 is restricted to pore formation only. Moreover, a separation between the cell wall and the cytoplasm was observed when Gram-negative bacteria were treated with a low concentration (20 AU/ml) of AN5-1.
    Matched MeSH terms: Staphylococcus aureus/drug effects*; Staphylococcus aureus/metabolism; Staphylococcus aureus/ultrastructure*
  20. Compressed Hydrogen-Induced Synthesis of Quaternary Trimethyl Chitosan-Silver Nanoparticles with Dual Antibacterial and Antifungal Activities
    Alli YA, Ejeromedoghene O, Oladipo A, Adewuyi S, Amolegbe SA, Anuar H, et al.
    ACS Appl Bio Mater, 2022 Nov 21;5(11):5240-5254.
    PMID: 36270024 DOI: 10.1021/acsabm.2c00670
    Quaternary Trimethyl Chitosan (QTMC) and QTMC-Silver Nanoparticles (QTMC-AgNPs) have been synthesized, characterized, and tested as antibacterial agents against Staphylococcus aureus, Escherichia coli, and two plant fungi (Sclerotium rolfsil and Fusarium oxysporum). The as-prepared water-soluble QTMC was in situ reacted with silver nitrate in the presence of clean compressed hydrogen gas (3 bar) as a reducing agent to produce QTMC-AgNPs. UV-vis, ATR-FTIR, HR-TEM/SEM, XPS, DLS, XRD, and TGA/DTG were employed to assess the optical response, morphology/size, surface chemistry, particle size distribution, crystal nature, and thermal stability of the synthesized QTMC-AgNPs, respectively. The as-prepared QTMC-AgNPs were quasi-spherical in shape with an average particle size of 12.5 nm, as determined by ImageJ software utilizing HR-TEM images and further validated by DLS analysis. The development of crystalline nanoparticles was confirmed by the presence of distinct and consistent lattice fringes with an approximate interplanar d-spacing of 2.04 nm in QTMC-AgNPs. The QTMC-AgNPs exhibited significant antibacterial activity with a clear zone of inhibition of 30 mm and 26 mm around the disks against E. coli and S. aureus, respectively. In addition, QTMC-AgNPs showed highly efficient antifungal activity with 100% and 76.67% growth inhibition against two plant pathogens, S. rolfsii and F. oxysporum, respectively, whereas QTMC revealed no impact. Overall, QTMC-AgNPs showed a promising therapeutic potential and,thus, can be considered for drug design rationale.
    Matched MeSH terms: Staphylococcus aureus
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