scholarly journals Synthesis and Antimicrobial Resistant Modulatory Activity of 2,4-Dinitrophenylhydrazone Derivatives as Agents against Some ESKAPE Human Pathogens

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Alberta Ade ◽  
Cedric D. K. Amengor ◽  
Abena Brobbey ◽  
Isaac Ayensu ◽  
Benjamin K. Harley ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Klebsiella Pneumoniae ◽  
Inhibitory Concentration ◽  
Fungal Species ◽  
Human Pathogens ◽  
Visible Spectroscopy ◽  
Active Compounds ◽  
Gram Negative ◽  
Uv Visible

A library of six novel phenylhydrazones were synthesized and evaluated for their in vitro antimicrobial and resistance modulating activity against a panel of Gram-positive, Gram-negative, and fungal species. The compounds were produced in good yields of 60–92% w/w and characterized using melting point, UV-visible spectroscopy, infrared, and nuclear magnetic resonance (1H, 13C, and DEPT-Q) techniques. Mass spectroscopy was used to confirm the identity of one of the most active compounds, 5 [SA5]. The phenylhydrazones showed activity against all the six selected microorganisms with minimum inhibitory concentration (MIC) values of the most active compounds, 1 [BP1] and 5 [SA5], at 138 µM (Klebsiella pneumoniae) and 165 µM (Streptococcus pneumoniae), respectively. Compound 1 [BP1] further demonstrated a high resistance modulatory activity at 1.078 µM against Streptococcus pneumoniae and Klebsiella pneumoniae.

scholarly journals In-vitro activity of levofloxacin against bacterial pathogens collected in China：A ten-year（2009-2018） retrospective study

2020 ◽  
Author(s):  
LU GAN ◽  
Yun Li ◽  
Yuan Lv ◽  
Bo Zheng
Keyword(s):  
Streptococcus Pneumoniae ◽  
Klebsiella Pneumoniae ◽  
Haemophilus Influenzae ◽  
Community Acquired Pneumonia ◽  
Resistance Rate ◽  
Gram Negative Bacteria ◽  
Icu Patients ◽  
Gram Negative ◽  
Resistance Rates

Abstract Background： This study was designed to evaluate the in-vitro activity of levofloxacin against bacterial pathogens collected from Chinese hospitalized patients between 2009 and 2018, and analysis the trends of levofloxacin resistance in China.Methods In this analysis, antimicrobial minimum inhibitory concentrations (MICs) experiments with levofloxacin and controls against a range of Gram-positive and Gram-negative bacteria collected from 2009 to 2018. MICs were determined using the agar dilution method according to the guidelines of Clinical and Laboratory Standards Institute (CLSI)，2019. Antimicrobial susceptibility was determined using CLSI breakpoints. Statistical tests were analysed by Statistical Package for the Social Sciences software (SPSS, Inc., Chicago, IL, USA), calculating the MIC90.Results In the past decade，the antibacterial activities of levofloxacin against Escherichia coli, Enterobacter cloacae, Pseudomonas aeruginosa and Stenotrophomonas maltophilia, which were common gram-negative bacteria, were stable; the resistance rates of these bacteria had no significant changes or decreased slightly. The levofloxacin resistance rates of Staphylococcus aureus and Enterococcus faecalis, which were gram positive bacteria, decreased from 48.4% and 36.9% in 2009-2010 to 22.8% and 25.7% in 2017-2018, respectively, respectively. The levofloxacin resistance rate among Haemophilus influenzae, Streptococcus pneumoniae and Streptococcus pneumoniae, the common pathogens of community acquired pneumonia (CAP), were less than 3%. The levofloxacin resistance rates for Klebsiella pneumoniae and Acinetobacter baumannii increased. No difference in the levofloxacin resistance rates by age group (18-64, 65-74, ≥75 years old age groups) was observed. The resistance rate of strains isolated from ICU patients was usually 10-20% higher than that of non-ICU patients.Conclusion In recent ten years, levofloxacin has continued to be active in-vitro against the strains in its antibacterial spectrum. No significant change of resistance rates was observed and it still has a good antibacterial effect on the main pathogenic bacteria of community-acquired pneumonia, such as Streptococcus pneumoniae, Haemophilus influenzae, Klebsiella pneumoniae and MSSA.

scholarly journals Biosynthesis and characterization of silver nanoparticles (AgNPs) using marine bacteria against certain human pathogens

2016 ◽  
Vol 2 (7) ◽  
pp. 152 ◽  
Author(s):  
J. Nasrin Begam
Keyword(s):  
Silver Nanoparticles ◽  
Marine Bacteria ◽  
Inhibitory Concentration ◽  
Bacterial Isolate ◽  
Xrd Analysis ◽  
Diffusion Method ◽  
Human Pathogens ◽  
Visible Spectroscopy ◽  
Disk Diffusion Method ◽  
Uv Visible

The present work investigates the synthesis of silver nanoparticles (AgNPs) by biological method using marine bacteria. The minimum inhibitory concentration (MIC) test was performed to find the inhibitory concentration of AgNO3 against marine bacterial isolate. After MIC study, the biogenic AgNPs was prepared through marine bacterial isolate and characterized by using UV-visible spectroscopy, Scanning Electron Microscopy (SEM), X Ray Diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). From the UV-visible spectroscopy, the absorption peak was found at 420 nm. In SEM image, it is confirmed that the sample contains spherical shaped silver nanoparticles and most of the particles were below 100 nm in size. In XRD analysis, it was confirmed that the silver nanoparticles are crystalline in nature, which was confirmed by the FTIR peak at 518 cm-1 corresponding to the Ag vibration present in crystalline structure. The antimicrobial activity of silver nanoparticles was determined by disk diffusion method, and found that silver nanoparticles have significant antibacterial activity against most of the pathogens.

Evaluation of Antibacterial and Antidiabetic Potential of Silver Nanoparticles using Eugenia Uniflora L. Seed Extract

2020 ◽  
Vol 13 (6) ◽  
pp. 5217-5225
Author(s):  
Guru Kumar Dugganaboyana ◽  
Chethankumar Mukunda ◽  
Suresh Darshini Inakanally
Keyword(s):  
Biomedical Applications ◽  
Pathogenic Bacteria ◽  
Seed Extract ◽  
Drug Formulation ◽  
Visible Spectroscopy ◽  
Plant Materials ◽  
X Ray ◽  
Eugenia Uniflora ◽  
Uv Visible

In recent years, green nanotechnology-based approaches using plant materials have been accepted as an environmentally friendly and cost-effective approach with various biomedical applications. In the current study, AgNPs were synthesized using the seed extract of the Eugenia uniflora L. (E.uniflora). Characterization was done using UV-Visible spectroscopy, X-ray diffraction (XRD), scanning electronic microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) analyses. The formation of AgNPs has confirmed through UV-Visible spectroscopy (at 466 nm) by the change of color owing to surface Plasmon resonance. Based on the XRD pattern, the crystalline property of AgNPs was established. The functional group existing in seed of E.uniflora extract accountable for the reduction of Ag+ ion and the stabilization of AgNPs was investigated. The morphological structures and elemental composition was determined by SEM and EDX analysis. With the growing application of AgNPs in biomedical perspectives, the biosynthesized AgNPs were evaluated for their antibacterial and along with their antidiabetic potential. The results showed that AgNPs are extremely effective with potent antidiabetic potential at a very low concentration. It also exhibited potential antibacterial activity against the three tested human pathogenic bacteria. Overall, the results highlight the effectiveness and potential applications of AgNPs in biomedical fields such as in the treatment of acute illnesses as well as in drug formulation for treating various diseases such as cancer and diabetes. It could be concluded that E. uniflora seed extract AgNPs can be used efficiently for in vitro evaluation of their antibacterial and antidiabetic effects with potent biomedical applications.

scholarly journals Characterization and selective inhibition of myristoyl-CoA:protein N-myristoyltransferase from Trypanosoma brucei and Leishmania major

2006 ◽  
Vol 396 (2) ◽  
pp. 277-285 ◽  
Author(s):  
Chrysoula Panethymitaki ◽  
Paul W. Bowyer ◽  
Helen P. Price ◽  
Robin J. Leatherbarrow ◽  
Katherine A. Brown ◽  
...  
Keyword(s):  
Trypanosoma Brucei ◽  
Leishmania Major ◽  
Homo Sapiens ◽  
Selective Inhibition ◽  
Fungal Species ◽  
Chemotherapeutic Agents ◽  
Human Pathogens ◽  
Ic50 Values

The eukaryotic enzyme NMT (myristoyl-CoA:protein N-myristoyltransferase) has been characterized in a range of species from Saccharomyces cerevisiae to Homo sapiens. NMT is essential for viability in a number of human pathogens, including the fungi Candida albicans and Cryptococcus neoformans, and the parasitic protozoa Leishmania major and Trypanosoma brucei. We have purified the Leishmania and T. brucei NMTs as active recombinant proteins and carried out kinetic analyses with their essential fatty acid donor, myristoyl-CoA and specific peptide substrates. A number of inhibitory compounds that target NMT in fungal species have been tested against the parasite enzymes in vitro and against live parasites in vivo. Two of these compounds inhibit TbNMT with IC50 values of <1 μM and are also active against mammalian parasite stages, with ED50 (the effective dose that allows 50% cell growth) values of 16–66 μM and low toxicity to murine macrophages. These results suggest that targeting NMT could be a valid approach for the development of chemotherapeutic agents against infectious diseases including African sleeping sickness and Nagana.

scholarly journals Bio Synthesis and Characterization of Silver Nanoparticles Using Lagenaria siceraria Leaf Extract and their Antibacterial Activity

2014 ◽  
Vol 38 ◽  
pp. 35-45 ◽  
Author(s):  
B. Anandh ◽  
A. Muthuvel ◽  
M. Emayavaramban
Keyword(s):  
Silver Nanoparticles ◽  
Leaf Extract ◽  
Face Centered Cubic ◽  
Lagenaria Siceraria ◽  
Human Pathogens ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Ft Ir ◽  
Uv Visible

The present investigation demonstrates the formation of silver nanoparticles by the reduction of the aqueous silver metal ions during exposure to the Lagenaria siceraria leaf extract. The synthesized AgNPs have characterized by UV-visible spectroscopy, X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) techniques. AgNPs formation has screened by UV-visible spectroscopy through colour conversion due to surface plasma resonance band at 427 nm. X-ray diffraction (XRD) confirmed that the resulting AgNPs are highly crystalline and the structure is face centered cubic (fcc). FT-IR spectrum indicates the presence of different functional groups present in the biomolecules capping the nanoparticles. Further, inhibitory activity of AgNPs and leaf extract were tested against human pathogens like gram-pastive (Staphylococcus aureus, Bacillus subtilis), gram-negative (Escherichia coli and Pseudomonas aeruginosa). The results indicated that the AgNPs showed moderate inhibitory actions against human pathogens than Lagenaria siceraria leaf extract, demonstrating its antimicrobial value against pathogenic diseases

scholarly journals FTIR and UV‒vis study of chemically engineered biomaterial surfaces for protein immobilization

2002 ◽  
Vol 16 (3-4) ◽  
pp. 351-360 ◽  
Author(s):  
Herman Mansur ◽  
Rodrigo Oréfice ◽  
Marivalda Pereira ◽  
Zélia Lobato ◽  
Wander Vasconcelos ◽  
...  
Keyword(s):  
Colorimetric Assay ◽  
Protein Immobilization ◽  
Research Field ◽  
Male Rats ◽  
Visible Spectroscopy ◽  
Functional Abnormality ◽  
Specific Chemical ◽  
Uv Visible

The biomaterials research field has broadened in the last 3 decades, including replacement of diseased or damaged parts, assist in healing, correct and improve functional abnormality, drug delivery systems, immunological kits and biosensors. Proteins play crucial role in almost every biological system. They are involved in enzymatic catalysis, transport and storage, coordinated motion, mechanical support, immune protection, control of growth and cell differentiation among many others. The immobilization of proteins onto surface functionalized substrates has been one of the most promising areas in bioengineering field. It is important to note that the term immobilization can refer either to a temporary or to a permanent localization of the biomolecule on or within a support. Proteins have very particular chain configurations and conformations that promote high levels of specificity during chemical interactions. In the present work, we aimed to study the phenomenon of protein immobilization onto biomaterial with chemically engineered surface. We have tailored the surface of the porous gels of SiO2with 5 different silane surface modifying agents: tetraethoxysilane (TEOS), 3‒mercaptopropyltrimethoxysilane (MPTMS) and 3‒aminopropyltriethoxysilane (APTES), 3‒glycidoxypropyltrimethoxysilane (GPTMS) and 3‒isocyanatopropyltriethoxysilane (ICPES). Fourier Transform Infrared Spectroscopy (FTIR) was used to characterize the presence of all specific chemical groups in the materials. The surface functionalized gels were then immersed in porcine insulin (PI) solutions for protein immobilization. The incorporation of protein within the gels was also monitored by FTIR spectroscopy. The kinetics of protein adsorption and desorption from the gel matrixin vitrotests were monitored by UV‒visible spectroscopy. We could not observe any evidence of denaturation of insulin after its desorption from gel matrices using UV‒visible spectroscopy technique.In vivotests with adult male rats were used to verify the immobilized insulin bioactivity after implantation of different biomaterial with functionalized surfaces. Plasma glucose levels were obtained by using the Glucose GOD‒ANA Colorimetric Assay. All surface modified materials have presented acute hypoglycemic peak response associated with the insulin bioactivity.

scholarly journals In Vitro Activity of Difloxacin against Canine Bacterial Isolates

2000 ◽  
Vol 12 (3) ◽  
pp. 218-223 ◽  
Author(s):  
R. van den Hoven ◽  
J. A. Wagenaar ◽  
R. D. Walker
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Proteus Mirabilis ◽  
In Vitro Activity ◽  
Bacterial Isolates ◽  
Postantibiotic Effect ◽  
Gram Negative ◽  
Neutral Ph ◽  
Staphylococcus Intermedius

The in vitro activity of difloxacin against canine bacterial isolates from clinical cases was studied in the United States and The Netherlands. Minimal inhibitory concentrations (MIC), the postantibiotic effect, the effect of pH on antimicrobial activity, and the bacterial killing rate tests were determined according to standard techniques. The MICs of American and Dutch isolates agreed in general. The MICs of the American gram-negative isolates ranged from 0.06 to 2.0 μg/ml, and the MICs of the Dutch gram-negative isolates ranged from 0.016 to 8.0 μg/ml. A few European strains of Proteus mirabilis and Klebsiella pneumoniae had relatively high MICs. Bordetella bronchiseptica also was less susceptible to difloxacin. The MICs of the American gram-positive cocci ranged from 0.125 to 4.0 μg/ml, and the MICs of Dutch isolates ranged from 0.125 to 2.0 μg/ml. Difloxacin induced a concentration-dependent postantibiotic effect that lasted 0.2–3 hours in cultures with Escherichia coli, Staphylococcus intermedius, Streptococcus canis, Proteus spp., and Klebsiella pneumoniae. There was no postantibiotic effect observed against canine Pseudomonas aeruginosa. Decreasing the pH of the medium increased the MIC of Proteus mirabilis for difloxacin. The MICs of Escherichia coli and Klebsiella pneumoniae were lowest at neutral pH and were slightly increased in acid or alkaline media. At a neutral pH, most tested bacterial species were killed at a difloxacin concentration of 4 times the MIC. Similar results were obtained when these same bacteria were tested against enrofloxacin. A Klebsiella pneumoniae strain in an acidic environment was readily killed at difloxacin or enrofloxacin MIC, but at neutral pH the drug concentration had to be raised to 4 times the MIC for a bactericidal effect. After 24 hours of incubation at pH 7.1, difloxacin and enrofloxacin had similar bactericidal activity for all bacteria tested except Staphylococcus intermedius. Against S. intermedius, difloxacin was more bactericidal than enrofloxacin.

scholarly journals Structural Characterization, Antimicrobial Activity, and In Vitro Cytotoxicity Effect of Black Seed Oil

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Sewara J. Mohammed ◽  
Hassan H. H. Amin ◽  
Shujahadeen B. Aziz ◽  
Aram M. Sha ◽  
Sarwar Hassan ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Structural Characterization ◽  
Seed Oil ◽  
Double Bonds ◽  
Visible Spectroscopy ◽  
Cytotoxic Effects ◽  
Black Seed ◽  
Uv Visible ◽  
Black Seed Oil

This study was aimed to investigate the structure of bioactive components of black seed oil (BSO) and their antimicrobial and cytotoxic effects. Initially, the structural examination was conducted using various spectroscopic techniques, such as FTIR, TLC, and UV-visible spectroscopy, which are important in determining substituents, functional groups, and the presence of conjugated double bonds in BSO. From the FTIR spectra, a variety of sharp, strong, and weak peaks were specified relating to the main components of thymoquinone (TQ), dithymoquinone, thymohydroquinone, and thymol in BSO. The results of UV-visible spectroscopy confirmed the presence of thymoquinone as a major compound, and conjugated double bonds were also found. In addition, qualitative TLC analysis was used to identify thymoquinone from the methanol-extracted layer in BSO, by calculating the retention factor (Rf) value. Furthermore, antimicrobial activity of BSO was studied against various types of bacteria. Strong bacterial inhibitory effects were observed, especially against Bacillus subtilis, with an average inhibition zone of 15.74 mm. Moreover, through the use of the MTT assay in vitro, it was shown that BSO does not exhibit any cytotoxicity towards human peripheral blood mononuclear cells (PBMCs). It was also found from the structural characterization of BSO that the existence of TQ is responsible for potential antibacterial activity without any cytotoxic effects. The main observation of this work is that BSO has antimicrobial activity even against methicillin-resistant Staphylococcus aureus (MRSA).

Dipyridophenazine Complexes of Cobalt(III): DNA Photocleavage and Photobiology

2005 ◽  
Vol 58 (3) ◽  
pp. 206 ◽  
Author(s):  
Alison M. Funston ◽  
Carleen Cullinane ◽  
Kenneth P. Ghiggino ◽  
W. David McFadyen ◽  
Stanley S. Stylli ◽  
...  
Keyword(s):  
Glioma Cell Line ◽  
In Vitro Cytotoxicity ◽  
Visible Spectroscopy ◽  
Rat Glioma ◽  
Cytotoxicity Studies ◽  
Strand Breakage ◽  
Uv Visible ◽  
Dna Strand ◽  
Dna Strand Breakage

The UV-visible spectroscopy and photochemistry of [Co(en)2(DPPZ)](ClO4)3 (DPPZ = dipyrido[3,2-a:2´,3´-c]-phenazine) in the presence of plasmid DNA and the nucleoside 2´-deoxygaunosine have been investigated. Evidence for the intercalation of the complex with DNA and photoinduced DNA strand breakage is found. The structurally related complexes [Co(en)2(DPPN)]Cl3 and [Co(en)2(DPPA)]Cl2, where DPPN = benzo[i]dipyrido[3,2-a:2´,3´-c]phenazine and DPPA = dipyrido[3,2-a:2´,3´-c] phenazine-11-carboxylic acid, have also been synthesized and characterized. In vitro cytotoxicity studies and photocytotoxicity studies of the complexes using the C6 rat glioma cell line are reported and indicate significant increases in toxicity following irradation.

scholarly journals Klebsiella pneumoniae Planktonic and Biofilm Reduction by Different Plant Extracts: In Vitro Study

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Lucas Paula-Ramos ◽  
Carlos Eduardo da Rocha Santos ◽  
Daphne Camargo Reis Mello ◽  
Lígia Nishiama Theodoro ◽  
Felipe Eduardo De Oliveira ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Minimum Inhibitory Concentration ◽  
Klebsiella Pneumoniae ◽  
Inhibitory Concentration ◽  
Juglans Regia ◽  
In Vitro Study ◽  
Chlorhexidine Digluconate ◽  
Planktonic Form ◽  
Microdilution Broth

This study evaluated the action of Pfaffia paniculata K., Juglans regia L., and Rosmarius officinalis L. extracts against planktonic form and biofilm of Klebsiella pneumoniae (ATCC 4352). Minimum inhibitory concentration (MIC) and minimum microbicidal concentration (MMC) values were determined for each extract by microdilution broth method, according to Clinical and Laboratory Standards Institute. Next, antimicrobial activity of the extracts on biofilm was analyzed. For this, standardized suspension at 107 UFC/mL of K. pneumoniae was distributed into 96-well microplates (n=10) and after 48 h at 37°C and biofilm was subjected to treatment for 5 min with the extracts at a concentration of 200 mg/mL. ANOVA and Tukey tests (5%) were used to verify statistical significant reduction (p<0.05) of planktonic form and biofilm. P paniculata K., R. officinalis L., and J. regia L. showed reductions in biomass of 55.6, 58.1, and 18.65% and cell viability reduction of 72.4, 65.1, and 31.5%, respectively. The reduction obtained with P. paniculata and R. officinalis extracts was similar to the reduction obtained with chlorhexidine digluconate 2%. In conclusion, all extracts have microbicidal action on the planktonic form but only P. paniculata K. and R. officinalis L. were effective against biofilm.

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