Synthesis, characterization and antibacterial activity of colloidal NiO nanoparticles

The Colloidal solutions of nickel oxide [NiO] nanoparticles synthesized via Nd-Yag pulse ablation of nickel immersed in H[2]O were studied. The created nanoparticles were characterized by UV-VIS absorption, Fourier transform infrared spectroscopy [FTIR] and transmission electron microscope [TEM]. FTIR characterization confirms the formation of nickel oxide nanoparticles. The optical band gap values, determined by UV-VIS absorption measurements, are found to be [4.5ev]. TEM shows that nanoparticles size ranged from 2-21 nm. The antimicrobial activity was carried out against pseudomonas aurogenisa, Escherichia coli [gram negative bacteria], Staphylococcus aureus and Streptococcus pneumonia [gram positive bacteria]. The NiO nanoparticles showed inhibitory activity in both strains of bacteria with best selectivity against gram-positive bacteria. The findings of present study indicate that NiO nanoparticles could potentiate the permeability of bacterial cell wall, and remarkably increase the accumulation of amoxicillin in bacteria, suggesting that NiO nanoparticles together with amoxicillin would facilitate the synergistic impact on growth inhibition of bacterial strains

Green synthesis, antimicrobial and cytotoxic effects of silver nanoparticles using Eucalyptus chapmaniana leaves extract

<p><b>OBJECTIVE</b>To synthesize silver nanopaticles from leaves extract of Eucalyptus chapmaniana (E. chapmaniana) and test the antimicrobial of the nanoparticles against different pathogenic bacteria, yeast and its toxicity against human acute promyelocytic leukemia (HL-60) cell line.</p><p><b>METHODS</b>Ten milliliter of leaves extract was mixed with 90 mL of 0.01 mmol/mL or 0.02 mmol/mL aqueous AgNO3 and exposed to sun light for 1 h. A change from yellowish to reddish brown color was observed. Characterization using UV-vis spectrophotometery and X-ray diffraction analysis were performed. Antimicrobial activity against six microorganisms was tested using well diffusion method and cytoxicity test using 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide, a yellow tetrazole was obtained on the human leukemia cell line (HL-60).</p><p><b>RESULTS</b>UV-vis spectral analysis showed silver surface plasmon resonance band at 413 nm. X-ray diffraction showed that the particles were crystalline in nature with face centered cubic structure of the bulk silver with broad beaks at 38.50° and 44.76°. The synthesized silver nanoparticles efficiently inhibited various pathogenic organisms and reduced viability of the HL-60 cells in a dose-dependent manner.</p><p><b>CONCLUSIONS</b>It has been demonstrated that the extract of E. chapmaniana leaves are capable of producing silver nanoparticles extracellularly and the Ag nanoparticles are quite stable in solution. Further studies are needed to fully characterize the toxicity and the mechanisms involved with the antimicrobial and anticancer activity of these particles.</p>

Immunological study of febrile fever: serum sialic acid, immunoglobulin levels [IgA, IgG and IgM], complement factors [C3 and C4] in patients with typhoid fever and brucellosis

Typhoid fever and brucellosis are frequent causes of bloodstream infections in many countries. The diagnosis of these infections is challenging because they can have diverse clinical manifestations with symptoms that overlap with a wide spectrum of other diseases. However, neither Widal nor Rose-Bengal agglutination assays are sufficiently sensitive, specific, or practical in areas of endemicity .In this study, it was undertaken to determine the sensitivity and specificity of clinical application of sialic acid in the evaluation of humoral immune response in patients with typhoid fever and brucellosis. Furthermore, the role of sialic acid [SA] was investigated as a possible biological marker and to assist diagnosis of disease. Serum samples from 35 patients with typhoid fever, 35 patients with brucellosis, and 60 healthy s individuals were tested for immunoglobulin A [IgA], IgG and IgM as well as complement factors C3 and C4 by single radial immunodiffusion assay. Determination of serum sialic acid for control, patient: and calibration samples was performed by the resorcinol method. The levels of all three classes of immunoglobulin and complement factors were higher in typhoid and brucellosis patients than in healthy individuals, beside significant increases in the serum levels of SA in patients with typhoid fever and brucellosis. There was no significant difference between serum levels of SA in typhoid and brucellosis patients as compared to the control group of healthy individuals. However, we were not able to observe a clinically meaningful difference with respect to sialic acid levels between these two categories. Sialic acid is a general disease marker than a specific marker and the none specificity of increase makes SA determination unsuitable as a specific marker. However it may have a clinical utility, which can be used in conjunction with other test