Displaying publications 61 - 80 of 873 in total

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  1. Ng XY, Fong KW, Kiew LV, Chung PY, Liew YK, Delsuc N, et al.
    J Inorg Biochem, 2024 Jan;250:112425.
    PMID: 37977020 DOI: 10.1016/j.jinorgbio.2023.112425
    Photodynamic therapy (PDT) has recently emerged as a potential valuable alternative to treat microbial infections. In PDT, singlet oxygen is generated in the presence of photosensitisers and oxygen under light irradiation of a specific wavelength, causing cytotoxic damage to bacteria. This review highlights different generations of photosensitisers and the common characteristics of ideal photosensitisers. It also focuses on the emergence of ruthenium and more specifically on Ru(II) polypyridyl complexes as metal-based photosensitisers used in antimicrobial photodynamic therapy (aPDT). Their photochemical and photophysical properties as well as structures are discussed while relating them to their phototoxicity. The use of Ru(II) complexes with recent advancements such as nanoformulations, combinatory therapy and photothermal therapy to improve on previous shortcomings of the complexes are outlined. Future perspectives of these complexes used in two-photon PDT, photoacoustic imaging and sonotherapy are also discussed. This review covers the literature published from 2017 to 2023.
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology
  2. Ghimire L, Banjara MR, Abdulla AM
    J Nepal Health Res Counc, 2024 Mar 31;21(4):616-622.
    PMID: 38616592 DOI: 10.33314/jnhrc.v21i4.4861
    BACKGROUND: Staphylococcus aureus (S.aureus) is an emerging antibiotic resistant bacterium responsible for various infections in human. Resistance to methicillin and vancomycin are of prime concern in S. aureus. The study aims to determine the minimum inhibitory concentration (MIC) of Vancomycin and evaluate the existence of mecA and vanA genes, associated with antibiotic resistance.

    METHODS: Clinical specimens from three Kathmandu hospitals were processed and S. aureus was identified using conventional microbiological procedures. MRSA was phenotypically identified with cefoxitin (30µg) disc diffusion, while vancomycin susceptibility was assessed using the Ezy MICTM stripes. The mecA and vanA genes were detected by polymerase chain reaction (PCR).

    RESULTS: Out of 266 S. aureus samples from various clinical specimen subjected for analysis, 77 (28.9%) were found methicillin-resistant (MRSA) and 10 (3.8%) were observed vancomycin-resistant (VRSA). Vancomycin resistant isolates showed a significant correlation between resistance to ampicillin, chloramphenicol, and cefoxitin. The mecA gene was found in 39 of the MRSA isolates, having 50.64% of MRSA cases, while the vanA gene was detected in 4 of the VRSA cases, constituting 40% of VRSA occurrences.

    CONCLUSIONS: The strains with higher vancomycin minimum inhibitory concentration values (≥ 1.5 μg/ml) displayed increased resistance rates to various antibiotics compared to strains with lower minimum inhibitory concentration values (< 1.5 μg/ml). The presence of vanA genes was strongly associated (100%) with vancomycin resistance, while the 10.3% mecA gene was identified from MRSA having resistance towards vancomycin also.

    Matched MeSH terms: Anti-Bacterial Agents/pharmacology
  3. Woh PY, Ng C
    Trop Biomed, 2024 Sep 01;41(3):298-309.
    PMID: 39548784 DOI: 10.47665/tb.41.3.010
    Rice is often associated with Bacillus cereus (B. cereus) food poisoning. This review aims to explore the food poisoning activity, antimicrobial resistance, and control measures of B. cereus in rice from 1974 to October 2023. We searched for eligible studies from the PubMed database based on explicit criteria following the PRISMA checklist. A total of 117 articles were collected, and the final analysis included 29 studies. Quality appraisal was performed using AMSTAR 2, SANRA 2, and Critical Appraisal Tool standards. B. cereus can grow and multiply in food to cause emetic vomiting or diarrheal syndrome. The primary etiology of B. cereus contamination is improper food handling and storage temperature during the cooking, cooling, and reheating stages of rice. The alarming rise of antimicrobial resistance in B. cereus to beta-lactam antibiotics necessitates alternatives from natural antimicrobial preservatives such as carvacrol, chitosan, or trans-cinnamaldehyde to prevent microbial infestation and toxin production. Implementing food safety strategies tailored to specific food settings, such as restaurants and factorymanufactured ready-to-eat rice, is critical for preventing food contamination by B. cereus. Given the heat-resistant spores and intoxication properties of B. cereus, it is important to develop effective interventions and hygienic protocols from farm to fork.
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology
  4. Kong P, Rosnan SM, Enomae T
    Carbohydr Polym, 2024 Dec 15;346:122612.
    PMID: 39245494 DOI: 10.1016/j.carbpol.2024.122612
    Polysaccharide-based edible films have been widely developed as food packaging materials in response to the rising environmental concerns caused by the extensive use of plastic packaging. In recent years, the integration of carboxymethyl cellulose (CMC) and chitosan (CS) for a binary edible film has received considerable interest because this binary edible film can retain the advantages of both constituents (e.g., the great oxygen barrier ability of CMC and moderate antimicrobial activity of CS) while mitigating their respective disadvantages (e.g., the low water resistance of CMC and poor mechanical strength of CS). This review aims to present the latest advancements in CMC-CS edible films. The preparation methods and properties of CMC-CS edible films are comprehensively introduced. Potential additives and technologies utilized to enhance the properties are discussed. The applications of CMC-CS edible films on food products are summarized. Literature shows that the current preparation methods for CMC-CS edible film are solvent-casting (main) and thermo-mechanical methods. The CMC-CS binary films have superior properties compared to films made from a single constituent. Moreover, some properties, such as physical strength, antibacterial ability, and antioxidant activity, can be greatly enhanced via the incorporation of some bioactive substances (e.g. essential oils and nanomaterials). To date, several applications of CMC-CS edible films in vegetables, fruits, dry foods, dairy products, and meats have been studied. Overall, CMC-CS edible films are highly promising as food packaging materials.
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology
  5. Moghadamtousi SZ, Kadir HA, Hassandarvish P, Tajik H, Abubakar S, Zandi K
    Biomed Res Int, 2014;2014:186864.
    PMID: 24877064 DOI: 10.1155/2014/186864
    Curcuma longa L. (Zingiberaceae family) and its polyphenolic compound curcumin have been subjected to a variety of antimicrobial investigations due to extensive traditional uses and low side effects. Antimicrobial activities for curcumin and rhizome extract of C. longa against different bacteria, viruses, fungi, and parasites have been reported. The promising results for antimicrobial activity of curcumin made it a good candidate to enhance the inhibitory effect of existing antimicrobial agents through synergism. Indeed, different investigations have been done to increase the antimicrobial activity of curcumin, including synthesis of different chemical derivatives to increase its water solubility as well ass cell up take of curcumin. This review aims to summarize previous antimicrobial studies of curcumin towards its application in the future studies as a natural antimicrobial agent.
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology*
  6. Ngeow YF, Cheng HJ, Chen JW, Yin WF, Chan KG
    Sensors (Basel), 2013;13(11):15242-51.
    PMID: 24284772 DOI: 10.3390/s131115242
    Klebsiella pneumoniae is one of the most common Gram-negative bacterial pathogens in clinical practice. It is associated with a wide range of disorders, ranging from superficial skin and soft tissue infections to potentially fatal sepsis in the lungs and blood stream. Quorum sensing, or bacterial cell-cell communication, refers to population density-dependent gene expression modulation. Quorum sensing in Proteobacteria relies on the production and sensing of signaling molecules which are mostly N-acylhomoserine lactones. Here, we report the identification of a multidrug resistant clinical isolate, K. pneumoniae strain CSG20, using matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF) mass spectrometry. We further confirmed quorum sensing activity in this strain with the use of high resolution tandem liquid chromatography quadrupole mass spectrometry and provided evidence K. pneumoniae strain CSG20 produced N-hexanoyl-homoserine lactone (C6-HSL). To the best of our knowledge, this is the first report on the production of N-hexanoylhomoserine lactone (C6-HSL) in clinical isolate K. pneumoniae.
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology
  7. Jafarzade M, Yahya NA, Shayesteh F, Usup G, Ahmad A
    J Microbiol, 2013 Jun;51(3):373-9.
    PMID: 23812818 DOI: 10.1007/s12275-013-2440-2
    This study was undertaken to investigate the influence of culture conditions and medium components on production of antibacterial compounds by Serratia sp. WPRA3 (JX020764) which was isolated from marine water of Port Dickson, Malaysia. Biochemical, morphological, and molecular characteristics suggested that the isolate is a new candidate of the Serratia sp. The isolate showed strong antimicrobial activity against fungi, Gram-negative and Gram-positive bacteria. This bacterium exhibited optimum antibacterial compounds production at 28°C, pH 7 and 200 rev/min aeration during 72 h of incubation period. Highest antibacterial activity was obtained when sodium chloride (2%), yeast extract (0.5%), and glucose concentration (0.75%) were used as salt, nitrogen, and carbon sources respectively. Different active fractions were obtained by Thin-Layer Chromatography (TLC) and Flash Column Chromatography (FCC) from ethyl acetate crude extracts namely OCE and RCE in different culture conditions, OCE (pH 5, 200 rev/min) and RCE (pH 7/without aeration). In conclusion, the results suggested different culture conditions have a significant impact on the types of secondary metabolites produced by the bacterium.
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology*
  8. Ibrahim D, Hong LS, Kuppan N
    Nat Prod Commun, 2013 Apr;8(4):493-6.
    PMID: 23738462
    The antibacterial efficiency of the methanolic extract of Phyllanthus niruri Linn. was investigated against pathogenic bacteria responsible for common infections of skin, and urinary and gastrointestinal tracts. The extract demonstrated antibacterial activities against all the Gram-positive and Gram-negative bacteria tested. The results obtained suggested that at higher concentrations the extract would eradicate the growth of bacterial cells. The bacterial cells, after exposure to the extract, showed complete alteration in their morphology, followed by collapse of the cells beyond repair. The study revealed that the methanolic extract of P. niruri may be an effective antibacterial agent to treat bacterial infections since the extract exhibited significant antimicrobial potency, comparable with that of the standard antibiotic chloramphenicol.
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology*
  9. Mai-Ngam K, Chumningan P
    Med J Malaysia, 2004 May;59 Suppl B:137-8.
    PMID: 15468856
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology*
  10. So AD, Shah TA, Roach S, Ling Chee Y, Nachman KE
    J Law Med Ethics, 2015;43 Suppl 3:38-45.
    PMID: 26243242 DOI: 10.1111/jlme.12273
    The growing demand for animal products and the widespread use of antibiotics in bringing food animals to market have heightened concerns over cross-species transmission of drug resistance. Both the biology and emerging epidemiology strongly support the need for global coordination in stemming the generation and propagation of resistance, and the patchwork of global and country-level regulations still leaves significant gaps. More importantly, discussing such a framework opens the door to taking modular steps towards solving these challenges - for example, beginning among targeted parties rather than all countries, tying accountability to financial and technical support, or taxing antibiotic use in animals to deter low-value usage of these drugs. An international agreement would allow integrating surveillance data collection, monitoring and enforcement, research into antibiotic alternatives and more sustainable approaches to agriculture, technical assistance and capacity building, and financing under the umbrella of a One Health approach.
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology*
  11. Wong FC, Tan ST, Chai TT
    Crit Rev Food Sci Nutr, 2016 Jul 29;56 Suppl 1:S162-70.
    PMID: 26193174 DOI: 10.1080/10408398.2015.1045967
    Many phytochemicals derived from edible medicinal plants have been investigated intensively for their various bioactivities. However, the detailed mechanism and their corresponding molecular targets frequently remain elusive. In this review, we present a summary of the research works done on phytochemical-mediated molecular targets, identified via proteomic approach. Concurrently, we also highlighted some pharmaceutical drugs which could be traced back to their origins in phytochemicals. For ease of presentation, these identified protein targets were categorized into two important healthcare-related fields, namely anti-bacterial and anti-cancer research. Through this review, we hope to highlight the usefulness of comparative proteomic as a powerful tool in phytochemical-mediated protein target identifications. Likewise, we wish to inspire further investigations on some of these protein targets identified over the last few years. With contributions from all researchers, the accumulative efforts could eventually lead to the discovery of some target-specific, low-toxicity therapeutic agents.
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology
  12. Jamal F, Aziz AH, Shafie MS
    Med J Malaysia, 1982 Jun;37(2):128-31.
    PMID: 7132831
    Two hundred strains of Klebsiella species isolated from clinical specimens over a four-month period were biotyped as Klebsiella aerogenes (173 strains), Klebsiella ozaenae (15 strains), Klebsiella edwardsii (5 strains), Klebsiella atlantae (2 strains) and Klebsiella oxytoca (1 strain). Klebsiella aerogenes and Klebsiella ozaenae were more resistant towards antibiotics when compared with other species. Colonial morphology on eosin methylene blue agar (Oxoid) was not found useful for differentiations of Klebsiella biotypes.
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology*
  13. Soon SH, Chai Kim Kai
    Med J Malaya, 1969 Dec;24(2):145-6.
    PMID: 4244140
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology*
  14. Ismail CAM, Deris ZZ, Bakar RA, Ismail N
    PMID: 33802184 DOI: 10.3390/ijerph18062834
    Despite modern medicine, there is an increasing trend for cases of the bacterial infection leptospirosis, and this has led to the exploration of alternative medicines from various sources including plants. The aim of this study was to investigate the in vitro anti-leptospiral activity of Phyllanthus amarus extracts alone and combined with penicillin G, ceftriaxone, and doxycycline. Antimicrobial susceptibility testing was performed using the microdilution broth technique upon methanol extract (ME), aqueous extract (AE), and antibiotics against the Leptospira interrogans serovars Australis, Bataviae, Canicola, and Javanica, to determine minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs). The results were analyzed using an ELISA microplate reader combined with microscopic analysis. Synergy testing using a checkerboard assay was performed to determine the fractional inhibitory concentration index values of extracts combined with antibiotics against leptospires. Scanning electron microscopy (SEM) was used to investigate morphological changes of leptospires caused by potential anti-leptospiral agents alone and combined with antibiotics. The MICs and MBCs for P. amarus extracts ranged from 100 to 400 µg/mL for AEs and from 400 to 800 µg/mL for MEs. Penicillin G was the most effective anti-leptospiral drug, with MICs and MBCs ranging from <0.01 to 0.78 and <0.01 to 3.13 µg/mL, respectively, followed by ceftriaxone, with both MICs and MBCs ranging from 0.05 to 0.78 µg/mL, and doxycycline, with MICs and MBCs ranging from 0.39 to 3.13 µg/mL and 12.5 to 25 µg/mL, respectively. Combinations of P. amarus extracts and antibiotics did not show synergistic effects on all tested Leptospira serovars, with some combinations demonstrating antagonistic effects. SEM analysis, however, showed distorted Leptospira surfaces. P. amarus AE performed better anti-leptospiral activity than P. amarus ME. The morphological effects of P. amarus extract alone and its combination with antibiotic on Leptospira cells revealed promising anti-leptospiral properties.
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology
  15. Ma C, Lo PK, Xu J, Li M, Jiang Z, Li G, et al.
    Bioresour Technol, 2020 Oct;314:123731.
    PMID: 32615447 DOI: 10.1016/j.biortech.2020.123731
    In this study, the differences on the physico-chemical parameters, lignocellulose degradation, dynamic succession of microbial community, gene expression of carbohydrate-active enzymes and antibiotics resistance genes were compared during composting systems of bagasse pith/pig manure (BP) and manioc waste/pig manure (MW). The results revealed that biodegradation rates of organic matter, cellulose, hemicellulose and lignin (29.14%, 17.53%,45.36% and 36.48%) in BP were higher than those (15.59%, 16.74%, 41.23% and 29.77%) in MW. In addition, the relative abundance of Bacillus, Luteimonas, Clostridium, Pseudomonas, Streptomyces and expression of genes encoding carbohydrate- active enzymes in BP were higher than those in MW based on metagenomics sequencing. During composting, antibiotics and antibiotic resistance genes were substantially reduced, but the removal efficiency was divergent in the both samples. Taken together, metagenomics analysis was a potential method for evaluating lignocellulose's biodegradation process and determining the elimination of antibiotic and antibiotic resistance genes from different composting sources of biomass.
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology
  16. Yazid AM, Ali AM, Shuhaimi M, Kalaivaani V, Rokiah MY, Reezal A
    Lett Appl Microbiol, 2000 Jul;31(1):57-62.
    PMID: 10886616
    Eighteen Bifidobacterium strains were tested for their susceptibility to a range of antimicrobial agents. All the strains tested, including the reference culture Lactobacillus acidophilus CH2, were susceptible to several groups of antimicrobial agents, they were cephalosporin (cefamandole, cefazolin, cefaperazone, cefoxitin), polypeptide (bacitracin), macrolide (erythromycin), penicillin (amoxicillin), phenicol (chloramphenicol) and beta-lactam (imipenem). Fourteen strains were resistant to more than 10 antibiotics. The reference culture was resistant to only three antibiotics. The results showed that bifidobacteria are resistant to a wide range of antimicrobial agents.
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology*
  17. Sivasothy Y, Ibrahim H, Paliany AS, Alias SA, Awang K
    Bioorg Med Chem Lett, 2013 Dec 1;23(23):6280-5.
    PMID: 24144849 DOI: 10.1016/j.bmcl.2013.09.082
    The rhizomes of Alpinia pahangensis Ridley yielded a new bis-labdanic diterpene for which the name pahangensin A (1) was proposed along with a new labdane diterpene, pahangensin B (2). Their structures were elucidated by spectroscopic methods including, 1D and 2D NMR techniques and LCMS-IT-TOF analysis. Pahangensin A (1) was found to be an antibacterial agent against Staphylococcus aureus, Bacillus cereus and Bacillus subtilis with MIC values less than 100 μg/mL, respectively. Pahangensin B (2) exhibited antibacterial activity (MIC <100 μg/mL) against B. cereus.
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology
  18. Ho JY, Jong MC, Acharya K, Liew SSX, Smith DR, Noor ZZ, et al.
    J Hazard Mater, 2021 03 05;405:124687.
    PMID: 33301976 DOI: 10.1016/j.jhazmat.2020.124687
    River systems in developing and emerging countries are often fragmented relative to land and waste management in their catchment. The impact of inconsistent waste management and releases is a major challenge in water quality management. To examine how anthropogenic activities and estuarine effects impact water quality, we characterised water conditions, in-situ microbiomes, profiles of faecal pollution indicator, pathogenic and antibiotic resistant bacteria in the River Melayu, Southern Malaysia. Overall, upstream sampling locations were distinguished from those closer to the coastline by physicochemical parameters and bacterial communities. The abundances of bacterial DNA, total E. coli marker genes, culturable bacteria as well as antibiotic resistance ESBL-producing bacteria were elevated at upstream sampling locations especially near discharge of a wastewater oxidation pond. Furthermore, 85.7% of E. faecalis was multidrug-resistant (MDR), whereas 100% of E. cloacae, E. coli, K. pneumoniae were MDR. Overall, this work demonstrates how pollution in river estuaries does not monotonically change from inland towards the coast but varies according to local waste releases and tidal mixing. We also show that surrogate markers, such dissolved oxygen, Bacteroides and Prevotella abundances, and the rodA qPCR assay for total E. coli, can identify locations on a river that deserve immediate attention to mitigate AMR spread through improved waste management.
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology
  19. Azmana M, Mahmood S, Hilles AR, Rahman A, Arifin MAB, Ahmed S
    Int J Biol Macromol, 2021 Aug 31;185:832-848.
    PMID: 34237361 DOI: 10.1016/j.ijbiomac.2021.07.023
    Over the last few years, several attempts have been made to replace petrochemical products with renewable and biodegradable components. The most challenging part of this approach is to obtain bio-based materials with properties and functions equivalent to those of synthetic products. Various naturally occurring polymers such as starch, collagen, alginate, cellulose, and chitin represent attractive candidates as they could reduce dependence on synthetic products and consequently positively impact the environment. Chitosan is also a unique bio-based polymer with excellent intrinsic properties. It is known for its anti-bacterial and film-forming properties, has high mechanical strength and good thermal stability. Nanotechnology has also applied chitosan-based materials in its most recent achievements. Therefore, numerous chitosan-based bionanocomposites with improved physical and chemical characteristics have been developed in an eco-friendly and cost-effective approach. This review discusses various sources of chitosan, its properties and methods of modification. Also, this work focuses on diverse preparation techniques of chitosan-based bionanocomposites and their emerging application in various sectors. Additionally, this review sheds light on future research scope with some drawbacks and challenges to motivate the researchers for future outstanding research works.
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology
  20. Qing S, Shoutian Q, Hongyan G, Ming Y, Swamy MK, Sinniah UR, et al.
    J Nanosci Nanotechnol, 2019 07 01;19(7):4109-4115.
    PMID: 30764978 DOI: 10.1166/jnn.2019.16282
    This study reports the biosynthesis of silver nanoparticles (AgNPs) using methanolic leaf extract of Pogostemon cablin Benth. (Patchouli) as a reducing agent, and their potent biological (antibacterial, antioxidant and anticancer) activities. The P. cablin extract when exposed to silver nitrate reduced silver ions to form crystalline AgNPs within 1 h of incubation at room-temperature. UV-visible spectra showed a sharp surface plasmon resonance (SPR) at around 430 nm for the biosynthesized AgNPs and the XRD pattern indicated the crystalline planes of the face centered cubic silver. The FE-SEM analysis revealed the occurrence of predominant spherical shaped AgNPs with a huge disparity in their particle size distribution with an average size of 25 nm, while, the FTIR data confirmed the bio-reduction and capping of AgNPs by several phytocompounds present in the methanolic leaf extract. AgNPs effectively inhibited the growth of all the tested human pathogenic bacterial strains (Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli), while, the methanolic leaf extract failed to inhibit the growth of S. aureus and P. aeruginosa. AgNPs showed the highest free radical scavenging activity (79.0 ± 0.76%) compared to methanolic leaf extract (68.3 ± 0.68%) at 100 μg/ml. Further, the cytotoxicity study using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) confirmed that AgNPs successfully inhibited the human colon adenocarcinoma cell line (HT-29) in a dose dependent manner. At higher concentrations (500 μg/ml), only 4% of cells survived after 72 hrs of exposure with IC50 value of 120 μg/ml. Thus, these findings offer a new source of biomolecules with diverse biological activities.
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology
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