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Phytomedicines Targeting Antibiotic Resistance through Quorum Sensing and Biofilm Formation Associated with Acne Vulgaris
Published in Namrita Lall, Medicinal Plants for Cosmetics, Health and Diseases, 2022
Isa A. Lambrechts, Namrita Lall
Antibiotic resistance can be defined as when the minimum inhibitory concentration against the targeted bacteria is higher than the concentration of the active that is available in vivo. Therefore, antibiotic resistance is when antibiotics cannot inhibit the microorganisms they previously were able to inhibit. The antibiotic resistance observed in biofilms could be due to two mechanisms of action: a reduction in the diffusion of antibiotics through the biofilm and a reduction in bacterial metabolism of the bacteria within the biofilm (Brandwein, Steinberg, and Meshner, 2016). Quorum sensing regulates genes involved in biofilm formation and dispersion; hence, biofilm formation and quorum sensing are linked.
Selective Antimicrobial Agents from Terrestrial Plants A Hope in the Battle of Infection
Published in Mahendra Rai, Chistiane M. Feitosa, Eco-Friendly Biobased Products Used in Microbial Diseases, 2022
Fadia S. Youssef, Mohamed L. Ashour
In addition, C. infortunatum leaves extracted with different solvents like methanol, distilled water, acetone, n-hexane and dichloromethane are examined for their antimicrobial potential against Staphylococcus pasteuri as Gram-positive bacteria and Pseudomonas aeruginosa as a Gram-negative one. It showed a maximum inhibition zone at 5% against both tested organisms. Besides, methanol extract showed high content of phenols. Quantification of flavonoids and tannins revealed that C. infortunatum leaves possess high flavonoid content, which is 12.17 mg/g and total tannins equal to 13.87 mg/g in acetone extract. Purification of anthocyanin from an in vitro culture of C. infortunatum was done using various chromatographic techniques, which was further checked for purity using HPLC and the molar absorptivity assay. The antimicrobial activity was assessed by determining the Minimum Inhibitory Concentration (MIC) and Minimum Killing Concentration (MKC). The purified anthocyanins showed significant antimicrobial activity with different degrees with C. albicans, S. aureus, P. aeruginosa displayed significant values followed by MRSA, E. coli and A. flavus, approaching that of standard antibiotics. In contrast, E. faecalis showed a higher resistance. The mechanistic behavior shown was proved by analysis of intracellular potassium leakage and bacterial membrane integrity (Sivamaruthi et al. 2018).
Toxic Effects and Biodistribution of Ultrasmall Gold Nanoparticles *
Published in Valerio Voliani, Nanomaterials and Neoplasms, 2021
Gunter Schmid, Wolfgang G. Kreyling, Ulrich Simon
To explore the potential therapeutic activity of cytotoxic usAuNP, Boda et al. investigated treatment option against staphylococcal infections [5]. The emergence of multidrug resistant bacteria, especially biofilm-associated staphylococci, requires novel antimicrobial agents. The authors tested antibacterial activity of AuNPs in a size range between 0.8 and 10 nm against planktonic gram-positive and gram-negative pathogenic bacteria. Among the gram-positive strains, Staphylococcus aureus and S. epidermidis were tested, while Escherichia coli and Pseudomonas aeruginosa comprised the gram-negative strains. In concentration-dependent toxicity assessment, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were evaluated. The results are summarized in Table 15.3.
Metabolomic profile, anti-trypanosomal potential and molecular docking studies of Thunbergia grandifolia
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2023
Heba A. S. El-Nashar, Ahmed M. Sayed, Hany A. M. El-Sherief, Mostafa E. Rateb, Lina Akil, Ibrahim Khadra, Taghreed A. Majrashi, Sara T. Al-Rashood, Faizah A. Binjubair, Mahmoud A. El Hassab, Wagdy M. Eldehna, Usama Ramadan Abdelmohsen, Nada M. Mostafa
The anti-trypanosomal activity was tested following the protocol of28. Briefly, 104 trypanosomes per ml of T. brucei brucei strain TC 221 were cultivated in Complete Baltz Medium. Trypanosomes were tested in 96-well plate chambers against different concentrations of test extracts at 10–200 μg/mL in 1% DMSO to a final volume of 200 μL. For controls, 1% DMSO as well as parasites without any test extract was used simultaneously in each plate to show no effect of 1% DMSO. The plates were then incubated at 37 °C in an atmosphere of 5% CO2 for 24 h using a CO2 incubator (CelMate®, ESCO™, Singapore). After the addition of 20 μL of Alamar Blue, the activity was measured after 48 and 72 h by light absorption using an MR 700 Microplate Reader at a wavelength of 550 nm with a reference wavelength of 650 nm. The minimum inhibitory concentration (MIC) values of the test extracts were quantified in by linear interpolation of three independent measurements. Suramin was used as a positive control (MIC = 0.23 μg/mL).
Preparation and optimization of aloe ferox gel loaded with Finasteride-Oregano oil nanocubosomes for treatment of alopecia
Published in Drug Delivery, 2022
Khaled M. Hosny, Waleed Y. Rizg, Eman Alfayez, Samar S. Elgebaly, Abdulmohsin J. Alamoudi, Raed I. Felimban, Hossam H. Tayeb, Rayan Y. Mushtaq, Awaji Y. Safhi, Majed Alharbi, Alshaimaa M. Almehmady
In the beginning, an agar dilution method was utilized in order to determine the minimal inhibitory concentration (MIC) values (Lamlertthon et al., 2007). To obtain the appropriate concentration range of tested material (0.01–3.0% V/V), different dispersions of FI-Or-NCu were introduced aseptically to 10 mL aliquots of sterile molten agar containing 0.5% tween 80. Then, the obtained solutions were vortexed for 30 seconds or until completely dispersed. Then, the solution was immediately poured into sterile Petri dishes then allowed to be placed for 60 min. The organisms that will be tested P. acne (1 L) from the prepared inoculum was added to the plates, which were allowed until the inoculum had set before being incubated at 37 °C for 72 h under anaerobic conditions as stated before. Subsequently, the utilized plates were observed and recorded for the presence or absence of growth. The results showed that the MIC was noted as the lowest concentration of test materials where the absence of growth was observed.
High-grade glioma therapy: adding flexibility in trial design to improve patient outcomes
Published in Expert Review of Anticancer Therapy, 2022
Xiaobu Ye, Karisa C. Schreck, Byram H. Ozer, Stuart A. Grossman
An alternative approach for patients with HGG would be to pre-clinically estimate a minimum threshold below which the drug is inactive. This is routinely done in infectious diseases where the minimum inhibitory concentration of an antibiotic is determined in the laboratory against a bacteria of interest. Efforts are then directed to determine if this minimum effective threshold level is achievable at the site of the infection in a patient. If the answer is yes, this is likely to be clinically effective but if the answer is no other therapeutic approaches should be explored. Although testing drug sensitivities in bacteria is far easier than in malignancies, estimating a target concentration below which the drug is unlikely to have a therapeutic effect is critically important to deciding if novel agents are likely to be effective in brain cancer efficacy trials.