Academic literature on the topic 'Antibacterial Assay'
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Journal articles on the topic "Antibacterial Assay"
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Peternel, Luka, Miha Kotnik, Andrej Preželj, and Uroš Urleb. "Comparison of 3 Cytotoxicity Screening Assays and Their Application to the Selection of Novel Antibacterial Hits." Journal of Biomolecular Screening 14, no. 2 (February 2009): 142–50. http://dx.doi.org/10.1177/1087057108329452.
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Cytotoxicity screening of new chemical entities in antibacterial drug discovery discerns between cytotoxic and antimicrobial activity, thus providing predictive evidence for selective toxicity. The objective of this study was to evaluate 3 cytotoxicity assays in identifying novel antibacterial hits with desired safety margins. The endpoints in assays comprised adenylate kinase (AK) release rate as an indicator of membrane rupture (Toxilight™), intracellular adenosine triphosphate (CellTiter-Glo™), and reduction of resazurin (CellTiter-Blue™) both as indicators of cell metabolic activity. In the CellTiter-Glo™ and the CellTiter-Blue™ assays, 7 of 8 selected compounds showed cytotoxicity, whereas in the Toxilight™ assay, 3 of 8 compounds significantly reduced cell viability in the ChoK1 and the JurkatE6.1 cell line. The CellTiter-Glo™ assay proved to be the most sensitive among the evaluated assays, and excellent Z′ values were obtained in the 96-well plate (Z′ > 0.83). The CellTiter-Glo™ assay was clearly superior to the CellTiter-Blue™ and the Toxilight™ assay for the initial cytotoxicity screening. Moreover, the application of the CellTiter-Glo™ assay to determine mammalian cell toxicity versus the antibacterial effect ratio contributed to early identification of antibacterial hits with desired safety margins. The chemical structures of these novel antibacterial hits are disclosed herein. ( Journal of Biomolecular Screening 2009:142-150)
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Akbar, Noor, Ruqaiyyah Siddiqui, Mazhar Iqbal, and Naveed Ahmed Khan. "Antibacterial Activities of Selected Pure Compounds Isolated from Gut Bacteria of Animals Living in Polluted Environments." Antibiotics 9, no. 4 (April 17, 2020): 190. http://dx.doi.org/10.3390/antibiotics9040190.
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Antibiotic resistance is a global threat to public health, further accelerated by the misuse of antibiotics in humans and animals. Our recent studies have shown that gut bacteria of animals living in polluted environments are a potential source of antibacterials. Gut bacteria of cockroaches, water monitor lizards and the turtle exhibited molecules such as curcumenol, docosanedioic acid, N-acyl-homoserine lactone, L-homotyrosine and Di-rhamnolipids. Using purified compounds, assays were performed to determine their antibacterial properties using serial dilution method, cytotoxic effects using lactate dehydrogenase release, and cell viability using MTT assay. The results revealed that the purified compounds exhibited significant antibacterial activities (p < 0.05) against selected Gram-negative (Pseudomonas aeruginosa) and Gram-positive bacteria (Streptococcus pyogenes) with effective MIC50 and MIC90 at µg concentrations, and with minimal effects on human cells as observed from LDH and MTT assays. These findings are significant and provide a basis for the rational development of therapeutic antibacterials. Future studies are needed to determine in vivo effects of the identified molecules together with their mode of action, which could lead to the development of novel antibacterial(s).
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Prastiyanto, Muhammad Evy, Inas Hasna Azizah, Hafizha Dara Haqi, Bagus Dwi Yulianto, Aulia Bella Agmala, Zhafira Dias Radipasari, Nita Ayu Dwi Astuti, and Arifani Rahma Putri. "In-vitro antibacterial activity of the seed extract of three-member Artocarpus towards Methicillin-Resistant Staphylococcus aureus (MRSA)." Jurnal Teknologi Laboratorium 9, no. 2 (December 31, 2020): 128–35. http://dx.doi.org/10.29238/teknolabjournal.v9i2.237.
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Methicillin-Resistant Staphylococcus aureus (MRSA) infections have created a critical need for the development of natural antibacterials from a biological source. This research aimed to investigate the antibacterial activity of the seed extract of three-member Artocarpus (Artocarpus heterophyllus, A. champeden, and A. camansi) against MRSA which are the most prevalent causes of infections in patients. Crude seed extracts of three-member Artocarpus were evaluated for their antibacterial activity against MRSA. The antibacterial activity against MRSA of the three extracts was assayed in vitro by the agar well diffusion assay and agar microdilution method and minimum bactericidal concentration. The antibacterial activity, calculated as a zone of inhibition and MIC, MBC values. The Crude seed extracts of three-member Artocarpus showed antibacterial activity against the MRSA in the agar well diffusion assay (1.5-9 mm inhibition diameter). The MIC value of extract showed at 15.62 mg/mL and the MBC value of seed extract of A. heterophyllus at 62.5 mg/mL, A. champeden at 31.25 mg/mL, A. camansi at 250 mg/mL. All seed extracts have the potential to be developed as antibacterial agents, particularly against MRSA strain. Studies on the antibacterial activity against MRSA can provide new information about the benefits seed of members of Artocarpus as a source of natural antibacterial.
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Sawai, J., R. Doi, Y. Maekawa, T. Yoshikawa, and H. Kojima. "Indirect conductimetric assay of antibacterial activities." Journal of Industrial Microbiology & Biotechnology 29, no. 5 (November 2002): 296–98. http://dx.doi.org/10.1038/sj/jim/7000314.
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Sawai, J., R. Doi, Y. Maekawa, T. Yoshikawa, and H. Kojima. "Indirect conductimetric assay of antibacterial activities." Journal of Industrial Microbiology and Biotechnology 29, no. 5 (November 1, 2002): 296–98. http://dx.doi.org/10.1038/sj.jim.7000314.
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Ivanenkov, Yan A., Renat S. Yamidanov, Ilya A. Osterman, Petr V. Sergiev, Vladimir A. Aladinskiy, Anastasia V. Aladinskaya, Victor A. Terentiev, et al. "Identification of N-Substituted Triazolo-azetidines as Novel Antibacterials using pDualrep2 HTS Platform." Combinatorial Chemistry & High Throughput Screening 22, no. 5 (August 8, 2019): 346–54. http://dx.doi.org/10.2174/1386207322666190412165316.
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Aim and Objective: Antibiotic resistance is a serious constraint to the development of new effective antibacterials. Therefore, the discovery of the new antibacterials remains one of the main challenges in modern medicinal chemistry. This study was undertaken to identify novel molecules with antibacterial activity. Materials and Methods: Using our unique double-reporter system, in-house large-scale HTS campaign was conducted for the identification of antibacterial potency of small-molecule compounds. The construction allows us to visually assess the underlying mechanism of action. After the initial HTS and rescreen procedure, luciferase assay, C14-test, determination of MIC value and PrestoBlue test were carried out. Results: HTS rounds and rescreen campaign have revealed the antibacterial activity of a series of Nsubstituted triazolo-azetidines and their isosteric derivatives that has not been reported previously. Primary hit-molecule demonstrated a MIC value of 12.5 µg/mL against E. coli Δ tolC with signs of translation blockage and no SOS-response. Translation inhibition (26%, luciferase assay) was achieved at high concentrations up to 160 µg/mL, while no activity was found using C14-test. The compound did not demonstrate cytotoxicity in the PrestoBlue assay against a panel of eukaryotic cells. Within a series of direct structural analogues bearing the same or bioisosteric scaffold, compound 2 was found to have an improved antibacterial potency (MIC=6.25 µg/mL) close to Erythromycin (MIC=2.5-5 µg/mL) against the same strain. In contrast to the parent hit, this compound was more active and selective, and provided a robust IP position. Conclusion: N-substituted triazolo-azetidine scaffold may be used as a versatile starting point for the development of novel active and selective antibacterial compounds.
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N, Asmathunisha. "Rapid Method for Detecting Bactericidal Effects of Mangrove Derived Silver Nanoparticles Using Resazurin Microdilution Assay." International Journal for Research in Applied Science and Engineering Technology 9, no. 8 (August 31, 2021): 2438–42. http://dx.doi.org/10.22214/ijraset.2021.37784.
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Abstract: Nanoparticles plays a vital role in the field of antimicrobial agents against pathogenic microorganisms. Screening of nanoparticles for antimicrobial activities is a time consuming and cumbersome process. Recently, a simple technique of using the dye resazurin has been used as an indicator of bacterial growth for testing antimicrobial activity on microtitre plate. However, this technique does not quantify the microbial load. Therefore, the present work was attempted to find a new antibacterial method employing the dye resazurin assay and haemocytometric counting of microbes for testing silver nanoparticles synthesised from Xylocarpus mekongensis .The bacterial strains E. coli, S. aureus and P. aeruginosa (multi-drug resistant strain) were used to evaluate the screening of mangrove extracts. Minimum inhibition concentration (MIC) was also calculated for the silver nanoparticles using ciproflaxcin as reference antibiotic. The antibacterial activity Xylocarpus mekongensis was carried out against all the three bacteria by the same method and the values were compared with reference antibiotic. The present study has suggested a rapid, dependable, easy and inexpensive method, suitable for testing the antibacterial activity of silver nanoparticles which are promising to develop as new antibacterials. Keywords: Mangroves, Silver, Nanoparticles, Resazurin, Antibacterials
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Park, Chung-Mu, and Hyun-Seo Yoon. "Antibacterial Activity of Litsea cubeba (May Chang) Essential Oil Against Streptococcus mutans and Porphyromonas gingivalis." Korean Society of Oral Health Science 11, no. 2 (June 30, 2023): 67–73. http://dx.doi.org/10.33615/jkohs.2023.11.2.67.
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Objectives: This study analyzed the antibacterial effects of Litsea cubeba essential oil (LCEO) against both Streptococcus mutans and Porphyromonas gingivalis, as well as inhibitory effect on biofilm formation. Methods: Antibacterial activity of LCEO was analyzed by minimum inhibition concentration on bacterial growth, disk diffusion and growth inhibitory assays. In addition, growth inhibitory effect of LCEO was also evaluated by biofilm formation assay. Results: LCEO significantly inhibited growth of S. mutans and P. gingivalis in a dose dependent manner. In addition, these results were coincided with the result of biofilm formation assay. Conclusions: LCEO exhibited potent antibacterial activity against both pathogens, which provides that LCEO might be used as a potential candidate for oral healthcare supplies.
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Shi, Danxia, Wenliang Xu, Marie Wong, and David G. Popovich. "An Improved Purification Method for Removing Colour Interference from 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl Tetrazolium Bromide (MTT) Antibacterial Assays." Applied Sciences 13, no. 8 (April 18, 2023): 5067. http://dx.doi.org/10.3390/app13085067.
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The MTT antibacterial assay is an important method in natural antibacterial component discovery. Researchers can use the MTT antibacterial assay to quickly and efficiently evaluate the antibacterial activity of natural compounds. The aim of this research was to find a method to reduce background colour and bacterial cell interference when using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay to study the antibacterial effect of phytochemicals. This study used NZ ‘Hass’ ripe avocado seed extract as an example to develop a silica gel column chromatography method that could combine with the MTT assay to remove the background colour and bacterial cells before the formazan measuring stage. This method is particularly suitable for MTT-based antibacterial inhibition studies when the tested phytochemical extracts have an interfering colour.
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Srusti S. N. R, Prathibha K. Y, and Keshamma E. "Assay of Antibacterial Activity of Gymnema sylvestre Extracts." international journal of engineering technology and management sciences 6, no. 5 (September 28, 2022): 847–51. http://dx.doi.org/10.46647/ijetms.2022.v06i05.131.
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The aim of the present study was to determination of antibacterial activities of ethanolic and aqueous leaf extracts of Madhunaashini (Gymnema sylvestre). Leaves of G. sylvestre was subjected to successive solvent extraction by continuous hot extraction (Soxhlet) with water and ethanol. The extracts were dissolved in dimethyl sulfoxide (DMSO) before testing the antibacterial activity. The antibacterial activity of leaf extracts G. sylvestre for Proteus mirabilis, E. coli and Pseudomonas aeruginosa was determined by agar well diffusion technique. Results delineated that zone of inhibition of G. Sylvestre for ethanolic & aqueous extracts for E. coli and P. mirabilis was found to be 17 mm & 13 mm and 19 mm & 16 mm respectively. Leaf extracts G. sylvestre for P. aeruginosa exhibited the zone of inhibition as 10 mm for ethanolic extract. In addition, ethanolic extract of G. Sylvestre exhibited antibacterial activity (19 mm) against P. mirabilis which is at par with that of standard antibiotic Streptomycin (20.5 mm). In conclusion, G. sylvestre could be used as an antibacterial agent since it was demonstrated from the current study findings that the ethanolic extract of G. sylvestre exhibited antibacterial activity at par with that of standard antibiotic streptomycin.
Dissertations / Theses on the topic "Antibacterial Assay"
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Cheung, Yin-mei. "Evaluation of a multiplex polymerase chain reaction assay for detection of silent fluoroquinolone-resistant determining mutations in streptococcus pneumoniae." Click to view the E-thesis via HKUTO, 2003. http://sunzi.lib.hku.hk/hkuto/record/B31970941.
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Cheung, Yin-mei, and 張燕湄. "Evaluation of a multiplex polymerase chain reaction assay for detection of silent fluoroquinolone-resistant determining mutations instreptococcus pneumoniae." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B31970941.
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Medu, Erere Ohwofasa. "Examination of the antibacterial activities of some semi-synthetic chalcone-derivatives alone and in combination with polymyxin B." Thesis, Robert Gordon University, 2013. http://hdl.handle.net/10059/832.
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In view of the increasing global challenge of bacterial resistance, there exists an urgent need for the rationale development of antibacterial compounds with either novel or multiple mechanisms of action. Two chalcone-derivatives, F1 and F23, demonstrated MICs within the range of 16 to >512 μg/ml against two plant pathogens (P. caratovoram and C. michiganensis subsp. michiganensis) as well as important clinical bacterial species. Both compounds displayed an MIC of 32 μg/ml against quinolone-resistant S. aureus. Whilst possessing weak activities individually, each semi-synthetic agent displayed notable synergistic action with polymyxin B against S. aureus, C. violaceum, E. coli and Ps. aeruginosa, thereby recording FICs within the range of <0.093 to 2 that indicated the existence of synergism in some instance. These chalcone compounds applied with polymyxin B displayed a notable FICindex of <0.093 against the Neisseriaceae C. violaceum, and a potential noteworthy capacity to extend the spectrum of activity of the latter antibiotic to include Gram-positive S. aureus species. F1 inhibited staphylococcal replication in broth and the combination of either of both chalcone-derivatives with polymyxin B instituted a metabolic blockage in S. aureus and other bacterial species as determined through a modified MTT reduction assay. The combined agents inflicted major disruptions to the S. aureus cytoplasmic membrane bilayer as evidenced by the release of intracellular potassium as well as the influx of Sytox Green fluorescent stain. Notable levels of cell membrane potential dissipation, leakage of intracellular potassium ions and blockage of reducing enzymes activities occurred within the first 30 minutes, well in advance of significant loss in cell viability that was recorded usually after 4 – 8 hours, suggesting these activities were prerequisites to cell death. In erythrocyte lysis assay, the synergistic combinations of 128 μg/ml of either of both chalcone derivatives with 128 μg/ml polymyxin B displayed the lowest degree of haemolysis, followed by that occurring with 32 μg/ml of the chalcone-derivatives combined with 256 μg/ml of the polypeptide antibiotic. In conclusion, further structure activity modifications aimed at improving the aqueous solubility of these chalcone-derivatives as well as the antibacterial activity recorded for certain combination concentrations of polymyxin B with either of these semi-synthetic agents may be required before considerations are made for the possibility for potential external formulations. Such preparations may include antiseptic creams, lotions, ointments, as well as aerosols that can be applied with nebulizers in targeted delivery for such cases like cystic fibrosis.
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Veale, Clinton Gareth Lancaster. "Synthetic analogues of marine bisindole alkaloids as potent selective inhibitors of MRSA pyruvate kinase." Thesis, Rhodes University, 2014. http://hdl.handle.net/10962/d1020893.
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Globally, methicillin resistant Staphylococcus aureus (MRSA) has become increasingly difficult to manage in the clinic and new antibiotics are required. The structure activity relationship (SAR) study presented in this thesis forms part of an international collaborative effort to identify potent and selective inhibitors of an MRSA pyruvate kinase (PK) enzyme target. In earlier work the known marine natural product bromodeoxytopsentin (1.6), isolated from a South African marine sponge Topsentia pachastrelloides, exhibited selective and significant inhibition of MRSA PK (IC₅₀ 60 nM). Accordingly bromodeoxytopsentin provided the initial chemical scaffold around which our SAR study was developed. Following a comprehensive introduction, providing the necessary background to the research described in subsequent Chapters, this thesis has been divided into three major parts. Part one (Chapter 2) documents the synthesis of two natural imidazole containing topsentin analogues 1.40, 1.46, five new synthetic analogues 1.58—1.61, 2.104. In the process we developed a new method for the synthesis of topsentin derivatives via selenium dioxide mediated oxidation of N-Boc protected 3-acetylindoles to yield glyoxal intermediates which were subsequently cyclized and deprotected to yield the desired products. Interestingly we were able to demonstrate a delicate relationship between the relative equivalents of selenium dioxide and water used during the oxidation step, careful manipulation of which was required to prevent the uncontrolled formation of side products. Synthetic compounds 1.40, 1.46, 1.58—1.61 were found to be potent inhibitors of MRSA PK (IC₅₀ 238, 2.1, 23, 1.4, 6.3 and 3.2 nM respectively) with 1000-10000 fold selectivity for MRSA PK over four human orthologs. In the second part of this thesis (Chapter 3) we report the successful synthesis of a cohort of previously unknown thiazole containing bisindole topsentin analogues 1.62—1.68 via a Hantzsch thiazole synthesis. Bioassay results revealed that these compounds were only moderate inhibitors of MRSA PK (IC₅₀ 5.1—20 μM) which suggested that inhibitory activity was significantly reduced upon substitution of the central imidazole ring of topsentin type analogues with a thiazole type ring. In addition in Chapter 3 we describe unsuccessful attempts to regiospecifically synthesize oxazole and imidazole topsentin analogues through a similar Hantzsch method. As a consequence of our efforts in this regard we investigated three key reactions in depth, namely the synthesis of 2.2, 3.38, 3.40, 3.41 via α-bromination of 3-acetylindole and the synthesis of indolyl-3-carbonylnitriles 2.13, 3.45—3.47 and α-oxo-1H-indole-3-thioacetamides 3.48—3.51. The investigation of the latter led to the isolation and elucidation of two anomalous N,N-dimethyl-1H-indole-3-carboxamides 3.52 and 3.53. Finally the third part of this thesis (Chapter 4) deals with in silico assessment of the binding of both the imidazole and thiazole containing bisindole alkaloids to the MRSA PK protein which initially guided our SAR studies. In this chapter we reveal that there appears to be no correlation between in silico binding predictions and in vitro MRSA PK inhibitory bioassay data. Superficially it seems that binding energy as determined by the docking program used for these studies correlated with the size of the indole substituents and did not reflect IC₅₀ MRSA PK inhibitory data. Although this led us to computationally explore possible alternative binding sites no clear alternative has been identified.
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Cai, Yanling. "Titanium Dioxide Photocatalysis in Biomaterials Applications." Doctoral thesis, Uppsala universitet, Nanoteknologi och funktionella material, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-160634.
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Despite extensive preventative efforts, the problem of controlling infections associated with biomedical materials persists. Bacteria tend to colonize on biocompatible materials and form biofilms; thus, novel biomaterials with antibacterial properties are of great interest. In this thesis, titanium dioxide (TiO2)-associated photocatalysis under ultraviolet (UV) irradiation was investigated as a strategy for developing bioactivity and antibacterial properties on biomaterials. Although much of the work was specifically directed towards dental materials, the results presented are applicable to a wide range of biomaterial applications. Most of the experimental work in the thesis was based on a resin-TiO2 nanocomposite that was prepared by adding 20 wt% TiO2 nanoparticles to a resin-based polymer material. Tests showed that the addition of the nanoparticles endowed the adhesive material with photocatalytic activity without affecting the functional bonding strength. Subsequent studies indicated a number of additional beneficial properties associated with the nanocomposite that appear promising for biomaterial applications. For example, irradiation with UV light induced bioactivity on the otherwise non-bioactive nanocomposite; this was indicated by hydroxyapatite formation on the surface following soaking in Dulbecco’s phosphate-buffered saline. Under UV irradiation, the resin-TiO2 nanocomposite provided effective antibacterial action against both planktonic and biofilm bacteria. UV irradiation of the nanocomposite also provided a prolonged antibacterial effect that continued after removal of the UV light source. UV treatment also reduced bacterial adhesion to the resin-TiO2 surface. The mechanisms involved in the antibacterial effects of TiO2 photocatalysis were studied by investigating the specific contributions of the photocatalytic reaction products (the reactive oxygen species) and their disinfection kinetics. Methods of improving the viability analysis of bacteria subjected to photocatalysis were also developed.
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Rojas, Maria J. "Study of Plants Used Against Infections by California Native American Tribes." DigitalCommons@CalPoly, 2020. https://digitalcommons.calpoly.edu/theses/2248.
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The objectives of this research were to evaluate the antibacterial activity and to determine the chemical composition of a list of medicinal plants used by Native Americans in California. Artemisia californica, Mimulus aurantiacus, Equisetum telmateia, Equisetum hyemale, and Marah fabacea were selected from a list of plants reported as having been used for ailments related to infections by tribes located in California. The extracts obtained through steam distillation from E. telmateia, E. hyemale and M. fabacea were assayed for in vitro antibacterial activity against 16 Gram-negative and 6 Gram-positive bacteria using disk diffusion assays and measuring the diameters of inhibition zones. E. telmateia showed the most promising antibacterial activity. The extracts from A. californica, M. aurantiacus and E. telmateia were analyzed for chemical composition, finding eucalyptol, thujone, eugenol, caryophyllene, germacrene D, and propanal as some of the secondary metabolites identified using GC-MS. Our results suggest that E. telmateia can be a potential source for novel antimicrobials against pathogenic bacteria.
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GRENGA, LUCIA. "Study of the biological role of the protein-protein interaction in the divisome assembling and functionality." Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2010. http://hdl.handle.net/2108/202281.
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L’incremento delle infezioni causate da batteri resistenti alle attuali terapie e la scarsità di farmaci efficaci per il loro trattamento spingono la comunità scientifica a cercare strategie innovative, per identificare nuove classi di farmaci antibatterici. Un modo per raggiungere questo obiettivo è quello di sviluppare farmaci che hanno nuovi meccanismi d’azione.
Diverse caratteristiche delle proteine dell’apparato di divisione (o divisoma) batterico suggeriscono che esse potrebbero essere dei bersagli ideali per nuovi antimicrobici. Poiché la divisione cellulare richiede molteplici interazioni proteina-proteina, utilizzare quest’ultime come target potrebbe rivelarsi fruttuoso. Prima di iniziare tali studi è, tuttavia, necessario discriminare, in condizioni di laboratorio, le interazioni essenziali per la vitalità della cellula da quelle transienti o non essenziali. Questo è particolarmente importante in processi che coinvolgono grandi complessi di proteine e interazioni multiple per assicurare che inibitori che bloccano una specifica interazione proteina-proteina lo facciano effettivamente.
Negli ultimi dieci anni, lo sviluppo di inibitori sia naturali che sintetici della proteina FtsZ o della formazione dei complessi FtsZ-ZipA e FtsZ-FtsA conferma come le proteine di divisione possano rappresentare un eccellente bersaglio per lo sviluppo di nuovi antibatterici.
Altri componenti del divisoma, e tra questi FtsQ, possono essere presi in considerazione come potenziali targets per nuovi antibatterici.
FtsQ, un componente del divisoma altamente conservato, gioca un ruolo fondamentale nell’assemblaggio delle proteine precoci e tardive della divisione. Il ruolo biologico di questa proteina non è ancora noto, ma la sua capacità di interagire con molti costituenti del divisoma è stata descritta sia mediante saggi di doppio ibrido, sia attraverso esperimenti di co-immunoprecipitazione. In questa tesi è descritto il comportamento di mutanti puntiformi di FtsQ, ottenuti in seguito a mutagenesi random indipendentemente dal loro fenotipo, nei quali è compromessa la capacità di FtsQ di interagire con i suoi partners della divisione. I risultati ottenuti permettono di identificare i residui di FtsQ coinvolti nell’interazione con le altre proteine di divisione e la determinazione del ruolo biologico di queste interazioni. Le conoscenze derivanti da questo studio oltre a contribuire alla comprensione di come le proteine di divisione si assemblano nel divisoma, rappresentano un punto di partenza per la progettazione di nuovi antibatterici in grado di distruggere il macchinario di divisione batterico.There is a pressing need to keep pace in the race against antibiotic resistance by producing a continuous stream of novel antibacterial agents. One way to achieve this is to develop drugs that have novel mechanisms of action. Several features of the bacterial cell-division proteins suggest that they could be good candidates as antibacterial targets. As cell division requires multiple protein–protein interactions, targeting such interactions could prove fruitful. However, before such studies are initiated, it would be necessary to first determine, in laboratory conditions, which interactions are essential and which are dispensable. This is particularly important in processes that involve large complexes of proteins and multiple interactions to ensure that inhibitors that block a specific protein–protein interaction do so effectively. In the past ten years, various natural or synthetic inhibitors against FtsZ protein or the FtsZ–ZipA complex or FtsA were identified. Although it is not known whether or not these compounds could have a medical application, these data confirm the hypothesis that these proteins represent an excellent antibacterial target. Other divisome components, and, amongst these, FtsQ, would be taken into account as potential targets for new antibiotics. FtsQ is a highly conserved component of the divisome that plays a central role in the assembly of early and late cell division proteins. The biological activity of this protein is still largely unknown, but its ability to interact with many components of the divisome was described by both two hybrid assays and co-immunoprecipitation experiments. This PhD thesis describes the behaviour of ftsQ point mutants, created by random mutagenesis without regard to their phenotype, in which FtsQ is impaired in its ability to interact with its E. coli division partners. Our results allow the identification of FtsQ residues involved in the interaction with other partner proteins and the determination of the biological significance of these interactions. The knowledge derived by this study could constitute not only the basis for understanding how these proteins assemble in the divisome, but also a starting point for the design of new antibacterial drugs that disrupt the bacterial division machinery.
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Rodrigues, Jacqueline Nunes. "CORRELAÇÃO ENTRE CITOTOXICIDADE, ALTERAÇÕES CROMOSSÔMICAS E ATIVIDADE ANTIBACTERIANA DE COMPOSTOS TRIAZENOS EM CÉLULAS DE MEDULA ÓSSEA." Universidade Federal de Santa Maria, 2013. http://repositorio.ufsm.br/handle/1/5986.
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Leukemias are a heterogeneous group of hematologic malignancies. The treatment of these neoplasms has been a challenge to the scientific community due to genetic diversity in leukemic cells. Acquired chromosomal abnormalities as well as modifications of gene expression are involved in the genesis of leukemia. Such facts have increased interest in the development of new effective chemotherapeutic agents that reach specific molecular targets. The compounds of the triazene class like dacarbazine and temozolomide have been used in the clinical treatment of various cancer types, including melanoma, leukemia and glioma. Two new compounds triazenes complexed with copper (CuII) were synthesized to identify new agents with antiproliferative and antibacterial activity. The Compounds 1 - Bis [ 1,3-bis (2-chlorofenyl) triazenido-N11,N13--O-methoxy-pyridine-N-copper(II)] - C36H34N8O2Cl4Cu2 and 2 - Bis [1,3-bis (2-fluorfenyl) triazenido-N11,N13--O-hidroxy-pyridine-N-copper(II)]-C34H28N8O2F4Cu2 were tested in leukaemic cells from AML, ALL, CML and MDS in vitro by MTT colorimetric assay. A higher-capacity of antiproliferative was verified in compound 1 with cytotoxicity (IC50: 3.8 to 28.6 μM) in most cell types at diagnosis, particularly in cells with chromosome abnormalities. This compound also showed in vitro cytotoxicity of relapse of ALL cells with karyotypic alterations. The cytotoxic activity was significantly higher in leukemic cells than in normal cells. The MIC values showed that compound 1 had higher activity than compound 2, showing narrow spectrum antibacterial activity against gram positive ATCCs and multiresistant bacterial strains. It was observed that Compound 1 was more promising in relation to the antiproliferative potential than the antimicrobial activity, even when compared to antineoplastic agents such as etoposide. Additional studies to understand the mechanism of action will soon be developed.As leucemias formam um grupo heterogêneo de neoplasias hematológicas. O tratamento destas neoplasias vem sendo um desafio à comunidade científica devido à diversidade genética nas células leucêmicas. Alterações cromossômicas adquiridas e modificações da expressão gênica estão envolvidas na gênese das leucemias. Isto tem estimulado o interesse no desenvolvimento de novos agentes quimioterapêuticos eficazes que atinjam alvos moleculares específicos. Os compostos da classe triazeno, tais como a dacarbazina e temozolomida, têm sido usados no tratamento clínico de diversos tipos de câncer, incluindo glioma, leucemia e melanoma. Dois novos compostos triazenos complexados com cobre (CuII) foram sintetizados com o objetivo de identificar novos agentes com atividade antiproliferativa e antibacteriana. Os compostos 1 - Bis[1,3-bis(2-clorofenil)triazenido-N11,N13--O-metóxi-piridina-N-cobre(II)] - C36H34N8O3Cl4Cu2 e 2- Bis[1,3-bis(2-fluorfenil)triazenido-N11,N13--O-hidróxi-piridina-N-cobre(II)] - C36H34N8O3F4Cu2 foram testados em células leucêmicas de LMA, LLA, LMC e SMD in vitro pelo teste colorimétrico MTT. O composto 1 apresentou melhor atividade citotóxica frente à maioria dos tipos celulares avaliados neste estudo (IC50: de 3,8 a 28,6 μM) especialmente em células com alterações cromossômicas. Este composto ainda apresentou citotoxicidade em células de recidiva de LLA com alterações cariotípicas. Ressaltamos que sua atividade citotóxica foi significativamente mais elevada em células leucêmicas do que em células normais. Os valores de CIM demonstraram que o composto 1 apresentou maior atividade antibacteriana que o composto 2, apresentando atividade de estreito espectro frente a cepas bacterianas gram positivas ATCCs e multirresistentes. Observou-se que o composto 1 foi mais promissor em relação ao potencial antiproliferativo do que ao potencial antibacteriano, inclusive quando comparado a agentes antineoplásicos como o etoposide. Estudos adicionais para melhor compreensão do mecanismo de ação deverão ser desenvolvidos.
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Bergamini, Fernando Rodrigues Goulart 1988. "Síntese, caracterização, modelagem molecular e ensaios antibacterianos de novos complexos de Ag(I) com ligantes biologicamente ativos." [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/249125.
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Orientador: Pedro Paulo CorbiDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química
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Resumo: Neste trabalho, são descritas a síntese e a caracterização de três complexos inéditos de prata com os ligantes L-butionina sulfoximina (BSO), ácido 2-tiazolidina carboxílico (2-TC) e ácido 4-tiazolidina carboxílico (4-TC). O complexo de prata com BSO foi caracterizado por um conjunto de análises químicas e espectroscópicas, a saber: análise elementar, análise térmica, espectroscopia na região do infravermelho (IV), espectroscopia Raman, espectroscopia de ressonância magnética no estado sólido de C (C-RMN), estudos por DFT e ensaios biológicos. Os complexos de prata(I) com 2-TC e 4-TC, por sua vez, foram caracterizados por análise elementar, análise térmica, espectroscopia na região do infravermelho (IV), espectroscopia de ressonância magnética no estado sólido de C-RMN e N-RMN, estudos por DFT e ensaios biológicos. O complexo de prata com BSO, [Ag2(BSO)], apresenta uma composição 2:1 metal/ligante, sendo que a coordenação do ligante a um dos átomos de prata ocorre através dos grupamentos amino e carboxilato, enquanto que a coordenação ao segundo átomo de prata ocorre através do nitrogênio da sulfoximina. Os complexos de prata com 2-TC e 4-TC também apresentam proporção 2:1 metal/ligante, com um átomo de prata coordenado através do nitrogênio e o segundo átomo de prata coordenado através do carboxilato. As análises biológicas revelaram que os complexos [Ag2(BSO)], [Ag2(2-TC)] e [Ag2(4-TC)] são efetivos sobre cepas patogênicas Gram-positivas de Staphylococcus aureus, e cepas Gram-negativas de Escherichia coli e Pseudomonas aeruginosa
Abstract: This work deals with the synthesis and characterization of three new silver(I) complexes with the ligands Lbuthionine sulfoximine (BSO), thiazolidine-2 carboxylic acid (2-TC) and thiazolidine-4 carboxylic acid (4-TC). The silver complex with BSO was characterized by elemental and thermal analyses, infrared and Raman spectroscopies, C nuclear magnetic resonance in the solid-state (C-NMR), DFT studies and biological assays. The silver(I) complexes with 2-TC and 4-TC were characterized by elemental and thermal analyses, infrared spectroscopy, C and N nuclear magnetic resonance in the solid-state, DFT studies and biological assays. The silver-BSO complex, [Ag2(BSO)], presents a 2:1 metal/ligand ratio. One of the silver(I) ion was shown to be coordinated through the amine nitrogen atom and the oxygen of carboxylate, while the second ion was shown to be coordinated through the nitrogen atom of the sulfoximine group. The silver(I) complexes with 2-TC and 4-TC also presented a 2:1 metal/ligand ratio, and are coordinated by the nitrogen and the oxygen atom of the carboxylate group. The biological assays revealed that the [Ag2(BSO)], [Ag2(2-TC)] and [Ag2(4-TC)] complexes are active against Gram-positive pathogenic strains of Staphylococcus aureus and Gramnegative pathogenic strains of Escherichia coli and Pseudomonas aeruginosa
Mestrado
Quimica Inorganica
Mestre em Química
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Sucena, Suelen Ferreira 1987. "Síntese, caracterização e estudo das atividades antibacterianas de complexos de Au(I), Ag(I) e Pd(II) com rimantadina." [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/249127.
Full textAbstract:
Orientadores: Pedro Paulo Corbi, André Luiz Barboza FormigaDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química
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Resumo: A rimantadina (C12H21N - rtd) 'e um agente antiviral, que inibe especificamente a replicacão do vírus influenza tipo A. A presença do grupo -NH2 confere a ela uma habilidade em se coordenar a diferentes íons metálicos. Neste trabalho foram sintetizado 3 novos complexos metálicos de Au(I), Ag(I) e Pd(II) com rimantadina. Os complexos foram preparados pela reacão de solucões aquosas ou alcoólicas da rimantadina com os respectivos sais de Au(I), Ag(I) e Pd(II). Os compostos foram caracterizados por um conjunto de análises químicas e espectroscópicas, bem como através de cálculos de Density Functional Theory (DFT). Os espectros no infravermelho (IV) e de ressonância magnética nuclear (RMN) da rtd livre e dos complexos indicaram a coordenação da rtd aos íons metálicos através do átomo de nitrogênio do grupo NH2. Os compostos foram analisados quanto as suas atividades biológicas antibacteriana sobre cepas de bactérias Gram-positivas e Gram-negativas. Os resultados mostraram que os complexos de Au(I) e Ag(I) são ativos sobre cepas de Staphylococcus aureus, Pseudomonas aeruginosa e Escherichia coli
Abstract: Rimantadine (C12H21N - rtd) is a antiviral agent which inhibit specifically the replication of the virus influenza A. The presence of group -NH2 confers the ability to coordinate with different metal ions. In this work 3 novel metal complexes of Au(I), Ag(I) e Pd(II) with rimantadine were synthesized. The complexes were prepared by the reaction of aqueous or alcoholic solutions of rimantadine with the respective salts of Au(I), Ag(I) e Pd(II). The compounds were characterized by a set of chemical and spectroscopic analyses, also by Density Functional Theory (DFT) studies. The infrared (IR) spectra and nuclear magnetic resonance (NMR) of the free rtd and of the compounds indicate the coordination of rtd to metallic ions through the nitrogen atom of group NH2. The compounds were analyzed concerning their antibacterial activities against Gram-positive and Gram-negative bacterial strains. The results showed that the Au(I) and Ag(I) complexes are active against Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli strains
Mestrado
Quimica Inorganica
Mestra em Química
Books on the topic "Antibacterial Assay"
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L, Dien Ariani. A bioautographic TLC assay [sic] for the detection of antibacterial activity of some Zingiberaceae in jamu gendong. Surabaya: Pusat Penelitian Obat Tradisional, Universitas Katolik Widya Mandala, 1997.
Find full textBook chapters on the topic "Antibacterial Assay"
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Otvos, Laszlo, and Mare Cudic. "Broth Microdilution Antibacterial Assay of Peptides." In Peptide Characterization and Application Protocols, 309–20. Totowa, NJ: Humana Press, 2007. http://dx.doi.org/10.1007/978-1-59745-430-8_12.
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Rütten, Anika, Wolfgang Wohlleben, Lena Mitousis, and Ewa Maria Musiol-Kroll. "A Whole-Cell Assay for Detection of Antibacterial Activity in Actinomycete Culture Supernatants." In Methods in Molecular Biology, 27–38. New York, NY: Springer US, 2022. http://dx.doi.org/10.1007/978-1-0716-2855-3_2.
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Arakawa, Kensuke. "Basic Antibacterial Assay to Screen for Bacteriocinogenic Lactic Acid Bacteria and to Elementarily Characterize Their Bacteriocins." In Lactic Acid Bacteria, 15–22. New York, NY: Springer New York, 2018. http://dx.doi.org/10.1007/978-1-4939-8907-2_2.
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Londonkar, Ramesh, and Maithilee Kesralikar. "In Vitro Anticancer Screening of Methanolic Extract of Stachytarpheta Mutabilis." In Proceedings of the Conference BioSangam 2022: Emerging Trends in Biotechnology (BIOSANGAM 2022), 188–204. Dordrecht: Atlantis Press International BV, 2022. http://dx.doi.org/10.2991/978-94-6463-020-6_19.
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AbstractIn therapeutic plants, phytochemicals are found in abundance. A family of verbena known as vervain (verbenaceae) consists of over 100 genera and nearly 2600 species. Among the Verbenaceae family is Stachytarpheta, a green perennial herb. The species is being examined in this study for its phytochemical, antioxidant, and anti-inflammatory properties. Stachytarpheta mutabilis methanol extracts were studied for their phytochemical screening, antimicrobial, anti-inflammatory, and anticancerous effects in the current study. Phytochemical study revealed the presence of alkaloids, flavonoids, glycosides, steroids, tannins, carbohydrates, and saponins, among other phytoconstituents. One fungus, Aspergillus niger, Staphylococcus aureus, and Bacillus subtilis, as well as four-gram (+) pathogens, including Staphylococcus aureus and Bacillus subtilis, and two gram (-) pathogens, including Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, and Klebsiella pneumoniae, were disc diffusion tested for antibacterial activity. The nitric oxide scavenging assay was used to test for anti-inflammatory efficacy in vitro. DPPH, ABTS, and total antioxidant tests were used to evaluate antioxidant activity. Analyses such as TLC, GC-MS, and were performed as per common procedure. A nitric oxide scavenging experiment was utilised to determine the anti-inflammatory properties of the drug in vitro. Tests for antioxidant activity were conducted using DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)), and total antioxidant tests. MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) analysis has been used to do anticancer screening. Extracts from Stachytarpheta mutabilis were found to include flavonoids, tannins and phenolic compounds as well as terpenoids and steroids in their phytochemical analysis. Squalene, octadecanal, and butan-1-one were found in the GC-MS study as were thirty other bioactive chemicals such as 4-isopropylcinnamic acid and octadecanoic acid. The methanolic fractions of plant extracts were shown to be effective against all bacteria. Anti-inflammatory and antioxidant experiments performed in the lab revealed the compounds’ potent inhibition activity. Analysis of the GC-MS data revealed the existence of thirty distinct components. MTT assay on the extract revealed anticancer activity. The data shows that the methanolic extract has a significant properties. Stachytarpheta mutabilis has therapeutic value and other pharmaceutical qualities may be assessed as a result of these results, which support the traditional usage of folk medicine as well.
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Maitip, Jakkrawut, Sirikarn Sanpa, Michael Burgett, and Bajaree Chuttong. "Antimicrobial Activity From Five Species of Stingless Bee (Apidae meliponini) Honey From South East Asia (Thailand)." In Advances in Environmental Engineering and Green Technologies, 53–68. IGI Global, 2023. http://dx.doi.org/10.4018/978-1-6684-6265-2.ch003.
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In Thailand, there have been limited investigations on the antibacterial properties of stingless bee honey. The purpose of this research is to investigate the physicochemical and antibacterial characteristics of five stingless bee species, including Lepidotrigona flavibasis, L. doipaensis, Lisotrigona furva, Tetragonula laeviceps species complex, and T. testaceitarsis complex from two geographical locations in Thailand: North (Chiang Mai) and Southeast (Chanthaburi). The moisture content from five species of stingless bee ranged from 27.6 to 32.0 g/100g. The range of pH in stingless bee honey was 3.5 to 3.8, which is slightly lower than the pH of Apis mellifera honey. The total acidity of stingless bee honey ranged from 44.0 to 216.9 meq/kg. The antimicrobial property of honey samples was investigated by the agar disc-diffusion method followed by MIC/MBC assay. Notably, with the exception of L. furva, stingless bee honeys were shown to exhibit antibacterial against the Gram-negative bacteria greater than Gram-positive bacteria.
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Hamilton, Paul, and Dale Christensen. "Surrogate Ligand-Based Assay Systems for Discovery of Antibacterial Agents for Genomic Targets." In Microbial Genomics and Drug Discovery, 173–85. CRC Press, 2003. http://dx.doi.org/10.1201/9780203911464.ch11.
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Oghenejobo, Michael, O. A. Opajobi, U. S. Oghenejobo Bethel, and U. E. Uzuegbu. "Determination of Antibacterial Evaluation, Phytochemical Screening and Ascorbic Acid Assay of Turmeric (Curcuma longa)." In Challenges and Advances in Pharmaceutical Research Vol. 1, 146–61. Book Publisher International (a part of SCIENCEDOMAIN International), 2022. http://dx.doi.org/10.9734/bpi/capr/v1/15376d.
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Guild, Braydon C. "Chapter 23. Genomics, Target Selection, Validation, and Assay Considerations in the Development of Antibacterial Screens." In Annual Reports in Medicinal Chemistry, 227–36. Elsevier, 1999. http://dx.doi.org/10.1016/s0065-7743(08)60585-0.
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Suhartati, Tati, Vicka Andini, Ilham Ramadhan, Yandri Yandri, and Sutopo Hadi. "9 Cytotoxicity test and antibacterial assay on the compound produced by the isolation and modification of artonin E from Artocarpus kemando Miq." In Organic and Natural Product Synthesis, 105–22. De Gruyter, 2022. http://dx.doi.org/10.1515/9783110752601-009.
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García-Cadme, Raisha, Irene García Cano, Oscar Castaño, and Javier Fernandez. "Perspective Chapter: Hydroxyapatite - Surface Functionalization to Prevent Bacterial Colonization." In Phosphate Minerals [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.106375.
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Microbial colonization is one of the main causes of implant loosening and rejection. Pathogenic contamination and the subsequent biofilm formation reduce the implant’s chance of survival and can be life-threatening to a patient. Among the many strategies employed to reduce the infection probability of bioceramics, surface functionalization plays a key role. This chapter is dedicated to describing the different strategies available to prevent bacterial colonization and the proliferation of hydroxyapatite-coated implants. Moreover, the factors intervening in the bacteria-implant interaction will be described, detailing the mechanisms involved during the contact, adhesion, and proliferation of bacteria. Finally, the characterization methods will be discussed, emphasizing the bioactivity and antibacterial assays.
Conference papers on the topic "Antibacterial Assay"
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Sahoo, Debasish, Virendra Vaishnav, Tanushree Chatterjee, and Navita Gupta. "HERBAL DIETARY SUPPLEMENT – A MODERN APPROACH IN COMPLEMENTARY AND ALTERNATIVE MEDICINE (CAM) IN HEALTH CARE SCIENCE." In International Conference on Public Health and Medical Sciences. Goodwood Conferences, 2022. http://dx.doi.org/10.35912/icophmeds.v1i1.24.
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Preliminary pharmacological study of herbal based dietary supplement formulation based on extracts or whole plants derived from fruits, root, berries, macrofungus and leaves as a promising, safe and effective alternative to synthetic and pharmaceutical dietary supplements, in-vitro studies such as antibacterial, anti-oxidant and anti-inflammatory activity for extract of dietary supplements. Nutritional assessment of nutritional attributes as suggested by AOAC method, Phytochemical analysis by standard chemical procedures, Quantitative estimate Alkaloid, Flavonoid, Phenolic, Tannin. In-vitro studies of anti-microbial (well diffusion), anti-oxidant assay (DPPH assay), anti-inflammatory assay (albumin denaturation assay). FTIR analysis for detection of different functional group. The finding suggest that the plant extract have a better nutritional aspect. The extracts for the food supplement showed positive results for anti-microbial, anti-oxidant and anti-inflammatory activity. More studies has to be concluded in respect to in-vivo tests that will conclude other pharmacological aspect of the food supplements. Reduced concentration of heavy metals and other contaminants will increase the therapeutical potency of the supplement. Stability, hold time study, dose and dosage form must be concluded in respect to achieve maximum efficacy. The herbal dietary supplement tend to better option against chemical based multi-vitamins and dietary supplements. These will enact the general well-being along with other pharmacological activities due to presence of phytochemicals present in the supplement.
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Muncal, Danilet Vi Abe. "094: DEVELOPMENT OF ANTIBACTERIAL AND ANTIFUNGAL BERBERINE-PVA GEL PATCH AND ITS IN-VIVO ASSAY AGAINST STAPHYLOCOCCUS AUREUS INFECTED WOUND." In Global Forum on Research and Innovation for Health 2015. British Medical Journal Publishing Group, 2015. http://dx.doi.org/10.1136/bmjopen-2015-forum2015abstracts.94.
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Iancu, Irina Mihaela, Laura Adriana Bucur, Verginica Schröder, and Manuela Rossemary Apetroaei. "TESTING THE BIOLOGICAL ACTIVITY OF LYTHRI HERBA EXTRACT FOR APPLICATIONS IN MEDICAL BIOTECHNOLOGIES." In GEOLINKS Conference Proceedings. Saima Consult Ltd, 2021. http://dx.doi.org/10.32008/geolinks2021/b1/v3/26.
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"Nowadays we are witnessing an increased interest in phytotherapy and implicitly for herbal products that have lower side effects. One medicinal plant whose popularity has decreased significantly in recent years is Lythrum salicaria L., loosestrife, known in Romanian traditional medicine for its beneficial effects against gastrointestinal diseases. The aim of this study is to evaluate the biological activity of three different extracts (aqueous, alcoholic, acetonic) from the flower tips of Lythrum salicaria L. using the BSLA (Brine Shrimp Lethality Assay) test and the antimicrobial activity of the extracts on two reference bacterial strains which are important for the medical field (Staphylococcus aureus and Escherichia coli) through the diffusimetric method. We demonstrated the fact that the Lythri herba plant product extracts (aqueous, alcoholic, and acetonic) lack acute toxicity, as well as the moderate antibacterial effect on the Gram-positive reference strain, Staphylococcus aureus, thus highlighting the possibility of using the plant in biomedical applications."
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Mudhar Bintang, Muhammad Ali Khumaini, and Teerapol Srichana. "Antibacterial Activity and <i>In Vitro</i> Cytotoxicity of Colistin in Sodium Deoxycholate Sulfate Formulation." In 5th International Conference and Exhibition on Pharmaceutical Sciences and Technology 2022. Switzerland: Trans Tech Publications Ltd, 2022. http://dx.doi.org/10.4028/p-19rsw3.
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Colistin has its problem with nephrotoxicity despite its capability for combatting multi-drug resistant gram-negative bacteria. Sodium deoxycholate sulfate (SDCS) has been shown to increase the safety profile of nephrotoxic drugs. This study aimed to explore the antimicrobial activity of colistin-SDCS versus free colistin against P. aeruginosa and investigate their cytotoxicity on kidney cells. The colistin micelles were formulated with SDCS followed by lyophilization and their properties were analyzed. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of colistin were determined using the broth microdilution method. The static time-kill kinetics were also employed to monitor the bactericidal activity of formulation over time. The cytotoxicity of formulations was analyzed using MTT colorimetric assay against kidney cells. The colistin-SDCS dry-powder was stable after reconstitution and resulted in 240 to 297 nm in particle size with the zeta potential of -22.8 to -23.4 mV. The colistin-SDCS formulations showed similar antibacterial activity against P. aeruginosa to pure colistin. MIC and MBC were 7.81 and 15.63 µg/mL, respectively. The static-time kill results displayed slightly better bactericidal activity at 24 h. The viability of kidney cells exposure to colistin-SDCS micelle was higher than that of pure colistin.
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Popa, Viorica-Mirela, Delia-Gabriela Dumbrava, Diana-Nicoleta Raba, Florina Radu, and Camelia Moldovan. "SPECTROPHOTOMETRIC DETERMINATION OF THE CONTENT OF CHLOROPHYLLS, CAROTENOIDS AND XANTHOPHYLL IN THE FRESH AND DRY LEAVES OF SOME SEASONING AND AROMATIC PLANTS FROM THE WESTERN AREA OF ROMANIA." In 22nd SGEM International Multidisciplinary Scientific GeoConference 2022. STEF92 Technology, 2022. http://dx.doi.org/10.5593/sgem2022v/6.2/s25.39.
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Aromatic plants have been one of the important concerns of man since the beginning of his existence. Seasoning plants, due to the presence in their composition of active principles with antibacterial and antifungal effect, allow a better preservation of food, a fact that over time has played an important role in preventing possible infections. Chlorophyll is the pigment that gives plants their green color and supports plants in absorbing energy and nutrients. Chlorophyll is found in most green plants and vegetables. Chlorophyll can also benefit the health of the human body as it is a natural source of antioxidants. Green chlorophyll pigments (chlorophyll a and b) and yellow pigments or carotenoide (carotenes and xanthophyll) represent photosynthetic or assimilatory pigments. The purpose of this paper consisted in studies on the comparative content of chlorophylls, carotenes and xanthophyll in the fresh and dry leaves of 12 seasoning and aromatic plants from the Western region of Romania, namely: celery, dill, parsley, lovage, rosemary, thyme, mint, basil, tarragon, sorrel, sage and stevia. Concentration of chlorophylls, carotenes and xanthophyll was determined by a spectrophotometric assay.
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Katanić Stanković, Jelena S., Nikola Srećković, and Vladimir Mihailović. "PHYTO-MEDIATED SYNTHESIS OF SILVER NANOPARTICLES USING AQUEOUS EXTRACT OF „BUGLOSSOIDES PURPUROCAERULEA“ (BORAGINACEAE) AND THEIR BIOACTIVITY." In 1st INTERNATIONAL Conference on Chemo and BioInformatics. Institute for Information Technologies, University of Kragujevac, 2021. http://dx.doi.org/10.46793/iccbi21.359ks.
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In this study, silver nanoparticles (AgNPs) have been synthesized using the aqueous extract of the aerial parts of B. purpurocaerulea, collected in Serbia. B. purpurocaerulea silver nanoparticles (Bp– AgNPs) synthesis was confirmed using UV-Vis spectroscopy and Fourier Transform Infrared Spectroscopy (FTIR). The biological potential of synthesized Bp-AgNPs was evaluated in vitro using ABTS assay for determining free radical scavenging potential and microdilution method for analysis of antimicrobial properties. Bp-AgNPs showed high antioxidant activity similar to Bp-extract, comparable to BHT. The synthesized nanoparticles exerted remarkable antibacterial effects, with minimal inhibitory concentration (MIC) values below 20 µg/mL. In the case of some bacterial strains, the results of Bp– AgNPs were comparable or similar to standard antibiotic erythromycin. The antifungal activity of Bp– AgNPs was moderate for most of the used strains. Nevertheless, several fungi were resistant to the NPs action, while two tested Penicillium species were extremely sensitive on Bp-AgNPs with MIC lower than 40 µg/mL. The antimicrobial properties of Bp-AgNPs can be useful for the development of new NPs-containing products.
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Peiris, Sriyani E., Gayani Malwattage, Raveena D. Ratnayake, Kasun L. Seneviratne, and Colin N. Peiris. "In Vitro Antibacterial Activity of Sulphur Nanoparticles as a Possible Application to Control Bacterial Blight Caused by Xanthomonas spp. in Anthurium." In SLIIT INTERNATIONAL CONFERENCE ON ADVANCEMENTS IN SCIENCES AND HUMANITIES [SICASH]. Faculty of Humanities and Sciences, SLIIT, 2022. http://dx.doi.org/10.54389/zjif6880.
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Anthurium blight is caused by Xanthomonas spp. which is regarded as the most threatening disease to the anthurium industry worldwide. Therefore, the current study was carried out to determine whether the application of sulphur nanoparticles (SNPs) is a possible solution for treating anthurium cultivars infected with Xanthomonas spp. The bacterium Xanthomonas was isolated using standard methods and a single bacterial colony was isolated using nutrient agar. The colonies were identified as Xanthomonas spp as they were gram-negative, motile rods due to the colony characters like yellow color because of the xanthin produced. The symptoms appeared in the pathogenicity test which was carried out by injecting purified Xanthomonas sp. into disease free anthurium plants confirmed the identification of the bacterial strain. Time-kill assay was conducted using Staphylococcus aureus, Escherichia coli and isolated Xanthomonas spp to investigate the behavior of SNPs. The results showed that suspension treated with 1g of SNPs for 30 minutes inhibited growth of Staphylococcus aureus colonies showing mean number of 7.92 CFU/ml compared to the control (mean number of colonies 9.09 CFU/ml ) treatment following 12 hours incubation. However, Escherichia coli, and isolated gram-negative rods (Xanthomonas spp) did not show positive influence for SNPs when compared to the control treatment. Therefore, further investigation is required to reach firm conclusions about this matter because the antimicrobial activity of SNPs varies depending on the type of target microorganisms, method and solvent used to dissolve SNPs. Keywords: Sulfur nanoparticles; Xanthomonas app; Anthurium; Bacterial blight
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AlBERMANI, Oruba K., Isrra Adnan Auda KHADHIM, and Nebras Mohammed SAHI. "ANTIMICROBIAL SUSCEPTIBILITY PATTERN AND THE ANTAGONISTIC EFFECT OF LACTOBACILLUS IN FIGHTING SHIGELLA SPP. ISOLATED FROM DIARRHEIC CHILDREN." In III.International Scientific Congress of Pure,Appliedand Technological Sciences. Rimar Academy, 2021. http://dx.doi.org/10.47832/minarcongress3-9.
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Background: Shigella is an major source of bacterial gastroenteritis in lack of health awareness in society. The handling of shigellos is mostly requires antibiotics. The using of probiotic of Lactic acid bacteria possess the counter effect against many dangerous bacterial pathogens which associated with gastroenteritis like Shigella spp. Aim: the purpose of this study to estimate the influence of lactic bacteria of the genus Lactobacillus on the population Shigella as a main pathogen involved in gastroenteritis in children. Patients and methods: A total of 50 stool specimens were collected during the period September2019 to January 2020 from diarrheic children patients age range(1-3)years. Standard bacteriological methods were used to isolate, identify, and determine the antimicrobial susceptibility pattern of Shigellaisolates, and we used fresh culture of Lactobacillus 24 h (previously isolated as member of fecal microbiota from healthy person and identified by molecular assay). Then we done centrifugation to obtain supernatant which have test bioactive materials like bacteriocin. These bacteriocin materials subjected to own antibacterial activity against other bacterial pathogen like Shigella spp. By using agar diffusion method . Results: All the 14 Shigella spp. isolates show 100% resistance to nalidixic acid,. cotrimoxazole , and High resistance to ciprofloxacin (85%), and moderate resistant of ampicillin (64%). In agar- well diffusion method indicated the high antagonistic activity of the strains of Lactobacillus 2, 3, and 4 isolated from health GI tract against all Shigella spp., as a result of their activity the total elimination of Shigella within 24 h was observed. conclusion: the Shigella spp. Strains exhibited antibiotic resistant against more one type of antiobiotic The lactobacilii strains tested during this study showed strong antimicrobial activity against Shigella spp. Key words: Shigellos is, Lactobacillus, 16S Rrna.
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Berechet, Mariana Daniela, Demetra Simion, Maria Stanca, Cosmin Andrei Alexe, Rodica Roxana Constantinescu, Maria Rapa, and Andreea Turcanu. "Antibacterial and antioxidant activities of lemon balm (Melissa officinalis L.) essential oil." In The 8th International Conference on Advanced Materials and Systems. INCDTP - Leather and Footwear Research Institute (ICPI), Bucharest, Romania, 2020. http://dx.doi.org/10.24264/icams-2020.ii.2.
Full textAbstract:
Lemon balm (Melissa officinalis L.) belongs to the Lamiaceae family. Essential oil extracted from the aerial parts of lemon balm has been investigated for the protection of fruits during storage, as insecticidal, as well as in medicine, due to its bioactive properties. In this paper, the composition and identification of components from Melissa officinalis L. essential oil were determined by gas chromatography coupled with mass spectrophotometry (GC/MS) analysis. Total phenol content (TPC) and the scavenging activity towards 2,2-diphenyl-1-picrylhydrazyl (DPPH·) and 2,2′-azino-bis (3-ethylbenzthiazoline)-6-sulfonic acid (ABTS+·) free radicals were evaluated by UV-VIS spectrometry. Antibacterial activities were carried out against Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae. Seventeen bioactive compounds were found as constituents of Melissa officinalis L. essential oil, among which o-cymene (19.735%), dehydro-p-cymene (17.180%), and limonene (11.589%) were found as the major components. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FT-IR) provided a confirmation for the chemical components of lemon balm essential oil identified by GC/MS. The values recorded for TPC and antioxidant activity were as follows: 54.72 mg GAE/g dry substance, 28.53% for DPPH, and 46.17% for ABTS assays, respectively. 100 µL lemon balm essential oil proved total antibacterial activity against the tested microorganisms. The results showed that the Melissa officinalis L. may be a good candidate as plant-derived antioxidant and antibacterial agent for medical footwear, wound dressings and other medical applications.
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Batsalova, Tsvetelina, Dzhemal Moten, Ivan Butenko, Balik Dzhambazov, and Alexander Vasilkov. "BIOLOGICAL AND PHYSICOCHEMICAL PROPERTIES OF GOLD AND IRON NANOPARTICLES PRODUCED BY GREEN SYNTHESIS METHOD." In 22nd SGEM International Multidisciplinary Scientific GeoConference 2022. STEF92 Technology, 2022. http://dx.doi.org/10.5593/sgem2022/6.1/s24.02.
Full textAbstract:
Gold and iron nanoparticles were generated via environmentally safe metal-vapor synthesis method applying acetone or toluene as organic dispersion medium. Biological properties of the nanoparticles were analyzed by the agar disc diffusion method using Gram-positive and Gram-negative bacteria and via in vitro cytotoxicity assays with different human cell lines. The obtained results revealed distinct biological activity profiles of the studied specimens. Fe nanoparticles (Fe NPs) demonstrated inhibitory effects against both Gram-positive and Gram-negative bacteria. Au nanoparticles (Au NPs) produced in acetone as organic dispersion medium reduced the growth of E. coli, but showed lower activity against the Gram-positive bacterium B. cereus. Au NPs derived from toluene organosol demonstrated the lowest level of antibacterial activity. In vitro analyses with human cells indicated mild cytotoxic effects of Au NPs against all tested cell lines. Fe NPs demonstrated time- and concentration-dependent cytotoxicity against colon adenocarcinoma cells. Iron nanoparticles derived from acetone organosol did not induce negative effect on noncancerous human cells, which indicates a good biocompatibility potential. Their physicochemical properties were characterized by transmission and scanning electron microscopy (TEM, SEM), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). TEM observations demonstrated that Au NPs and Fe NPs have average sizes of 8.3 nm and 1.8 nm. Characteristics of the photoelectron spectra showed that gold is in the state of Au0, and the spectrum of iron is close in shape to the spectrum of Fe3O4.