Lowest MBC Values Research Articles

Methanolic Extract Of Swietenia macrophylla Exhibits Antibacterial And Antibiofilm Efficacy Against Gram-Positive Pathogens

Gram-positive pathogens cause infections such as pneumonia, skin infections, anthrax, and sinusitis. The objective of this study was to determine the phytochemical profile, antibacterial and antibiofilm efficacy of Swietenia macrophylla methanolic extract (SMME) against Gram-positive pathogens. The secondary metabolites of SMME were analyzed using GC-MS while the antibacterial efficacy of SMME against Staphylococcus aureus ATCC 33862, Bacillus cereus ATCC 11778, Streptococcus pneumonia ATCC 19615, and Clostridium sporogenes ATCC 13124 was assessed using MIC and MBC assays. Biofilm biomass assay and time-kill assay were performed to determine the antibiofilm activity of SMME against the pathogens. Results demonstrated that six common antibacterial secondary metabolites were present in the SMME. The major compound was found to be β-amyrin (22.8%). The SMME showed the lowest MIC values against B. cereus (31.25 µg/mL) and C. sporogenes (31.25 µg/mL) and the lowest MBC value against S. aureus (1000 µg/mL). The SMME also significantly (p<0.05) inhibited all the biofilms. It started to inhibit S. pneumonia and C. sporogenes biofilms after 12 h of exposure. On the other hand, the BIC50 value showed that the SMME was most effective against B. cereus. In conclusion, the secondary metabolites in the SMME may contribute to the antibacterial and antibiofilm efficacy against Gram-positive pathogens.

Duchsnea indica plant extract mediated synthesis of copper oxide nanomaterials for antimicrobial activity and free-radical scavenging assay

Green synthesis of metallic nanoparticles has developed into a key topic in nanotechnology due to its potential in the development of new technologies. The method described in current study is safe for the environment and doesn't include any harmful components. Chitosan and the aromatic medicinal herb Duchsnea indica have been combined to produce environmentally friendly copper oxide nanoparticles and nanocomposites (CuO NPs/NCs). Their synthesis was verified by UV–Visible spectroscopy, FT-IR, X-ray diffraction (XRD), EDX, and TEM analysis. The FTIR spectra of the CuO NPs/NCs showed the presence of functional groups, such as phenolic and flavonoids that may convert Cu2+ ions into CuO NPs/NCs. The XRD pattern indicates that CuO NPs/NCs are crystalline, and have a face-centered cubic (FCC) crystalline structure. TEM analysis revealed that particles are having nearly spherical shape with an average size between 2 and 31 nm. The antibacterial activity of these CuO NPs/NCs against Gram-positive, Gram-negative, and fungal infections has been particularly convincing. The lowest MBC values were 91.24 μg/mL and 99.50 μg/mL, whereas the lowest MIC values were 10.30 μg/mL and 10.84 μg/mL, respectively. According to the DPPH scavenging assay, the antioxidant activity of CuONPs/NCs have shown highest degradation potential of 99.31% at a very low concentration of 50 ppm.

Phytochemically stabilized chitosan encapsulated Cu and Ag nanocomposites to remove cefuroxime axetil and pathogens from the environment

Antibiotics have been a source of concern since they are causing resistance in bacteria that live in water and air. As a result, green technology was used to manufacture silver and copper nanoparticles, which were encapsulated with the biopolymer chitosan derived from the root extract of the Potentilla astrosanguinea plant. XRD, FTIR, TEM, EDX, and UV–Visible spectroscopy were methods used for structural and spectroscopic analysis. These nanomaterials have a roughly spherical 2–30 nm average size and a face-centered cubic (FCC) shape, according to the findings. The photocatalytic drug degradation and antibacterial properties of the produced nanocomposites were outstanding, with some resistance lasting longer than 180 days. The current study discovered that under UV light exposure, silver nanocomposites degrade drugs rapidly within 40 min, with an average rate of over 95%, while copper nanocomposites degrade drugs rapidly within 70 min, with an average rate of 84%. These nanocomposites have demonstrated exceptionally compelling antibacterial action against Gram-positive, Gram-negative, and fungal pathogens in addition to photocatalytic activity. The lowest recorded MIC values were 10.30 μg/mL and 10.84 μg/mL, respectively, whereas the lowest MBC values were 91.24 μg/mL and 99.50 μg/mL.

Preparation of Nanostructured Lipid Carriers (NLCs) Loading Violacein Extract for Anti-Acne Products

The objective of this research is to evaluate the antimicrobial activity of Nanostructured Lipid Carriers (NLCs) loading violacein extract. The extract was tested for the antimicrobial activities against 3 strains of pathogenic bacteria; namely Cutibacterium acnes ATCC 6919, Staphylococcus aureus ATCC 6538 and Staphylococcus epidermidis ATCC 12228 by agar well diffusion assay. The result indicated that the violacein extract from Chromobacterium violaceum ATCC 12472 has strongest antibacterial effect against C. acnes, S. aureus and S. epidermidis with MIC values in range of 0.0146-0.4688 mg/mL with the lowest MBC value of 0.0146 mg/mL against C. acnes. Violacein extract loaded Nanostructured Lipid Carriers (NLCs) for anti-acne products were prepared by using melt-emulsification technique. The studied factors are the ratio of liquid lipid and solid lipid (LL:SL), surfactant concentration and sonication time. The Ratio of Oleic acid and Compritol® 888 ATO (3:1) with Tween 20 (1.5% w/w) and sonication time of 10 minute (F8 formulation) are an optimizing condition for NLC-Base. The resulted formulations showed the NLC-Base had average particle size of 213.7±2.42 nm with a polydispersity index of 0.239±0.003 and Zeta potential of -26.6±0.45 mV. After that, violacein extract (2% w/w) was loaded into the NLCs (VIO-NLCs). Antibacterial activity of VIO-NLCs 2 % was determined by using agar dilution. The result showed that VIO-NLCs 2 % can inhibit the growth of C. acnes for 60 days during storage. Furthermore, VIO-NLCs 2 % can also act as S. aureus and S. epidermidis inhibitor within 30 days shelf life.

Green synthesis of titanium dioxide nanoparticles using Azadirachta indica leaf extract and evaluation of their antibacterial activity

The present study deals with the synthesis of titanium dioxide nanoparticles using Azadirachta indica leaf extract. FTIR study reveals the presence of terpenoids, flavonoids and proteins considered responsible for the formation and stabilization of titanium dioxide nanoparticles while the XRD studies revealed the crystalline nature of titanium dioxide nanoparticles. Transmission electron microscopy images showed the spherical shape and size ranged from 15 to 50 nm. SEM study revealed that TiO2 nanoparticles were spherical in shape and their size ranged from 25 to 87 nm. The antibacterial activity of synthesized TiO2 nanoparticles and TiO2 compound was assayed against Escherichia coli, Bacillus subtilis, Salmonella typhi and Klebsiella pneumoniae. The results of the present study showed that TiO2 nanoparticles inhibited the growth of all the tested microorganisms. The antibacterial effect is more pronounced in case of TiO2 nanoparticles as compared with TiO2 compound. The lowest MIC (minimum inhibitory concentration) value i.e. 10.42 μg/mL of nanoparticles was observed against Salmonella typhi and Escherichia coli whereas lowest MBC value i.e. 83.3 μg/mL was observed against Klebsiella pneumoniae.