Nooruddin Thajuddin

PLANT EXTRACT MEDIATED SYNTHESIS OF SILVER AND GOLD NANOPARTICLES AND ITS ANTIBACTERIAL ACTIVITY AGAINST CLINICALLY ISOLATED PATHOGENS

Biosynthesis of nanoparticles is under exploration is due to wide biomedical applications and research interest in nanotechnology. Bioreduction of silver nitrate (AgNO(3)) and chloroauric acid (HAuCl(4)) for the synthesis of silver and gold nanoparticles respectively with the plant extract, Mentha piperita (Lamiaceae). The plant extract is mixed with AgNO(3) and HAuCl(2), incubated and studied synthesis of nanoparticles using UV-Vis spectroscopy. The nanoparticles were characterized by FTIR, SEM equipped with EDS. The silver nanoparticles synthesized were generally found to be spherical in shape with 90 nm, whereas the synthesized gold nanoparticles were found to be 150 nm. The results showed that the leaf extract of menthol is very good bioreductant for the synthesis of silver and gold nanoparticles and synthesized nanoparticles active against clinically isolated human pathogens, Staphylococcus aureus and Escherichia coli.

Biosynthesis of silver nanoparticles from Tribulus terrestris and its antimicrobial activity: a novel biological approach.

In the recent decades, increased development of green synthesis of nanoparticles is inevitable because of its incredible applications in all fields of science. There were numerous work have been produced based on the plant and its extract mediated synthesis of nanoparticles, in this present study to explore that the novel approaches for the biosynthesis of silver nanoparticles using plant fruit bodies. The plant, Tribulus terrestris L. fruit bodies are used in this study, where the dried fruit body extract was mixed with silver nitrate in order to synthesis of silver nanoparticles. The active phytochemicals present in the plant were responsible for the quick reduction of silver ion (Ag(+)) to metallic silver nanoparticles (Ag(0)). The reduced silver nanoparticles were characterized by Transmission Electron Microscope (TEM), Atomic Force Microscope (AFM), XRD, FTIR, UV-vis spectroscopy. The spherical shaped silver nanoparticles were observed and it was found to be 16-28 nm range of sizes. The diffraction pattern also confirmed that the higher percentage of silver with fine particles size. The antibacterial property of synthesized nanoparticles was observed by Kirby-Bauer method with clinically isolated multi-drug resistant bacteria such as Streptococcus pyogens, Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis and Staphylococcus aureus. The plant materials mediated synthesis of silver nanoparticles have comparatively rapid and less expensive and wide application to antibacterial therapy in modern medicine.

Biogenic silver nanoparticles for cancer treatment: An experimental report

A generation of nanoparticles research has discussed recently. It is mandatory to elaborate the applications of biogenic nanoparticles in general and anticancereous property in particular. The present study was aimed to investigate the in vitro cytotoxicity effect of biogenic silver nanoparticles (AgNPs) against human breast cancer (MCF-7) cells towards the development of anticancer agent. Biogenic AgNPs were achieved by employing Sesbania grandiflora leaf extract as a novel reducing agent. It was well characterized by FESEM, EDAX and spectral studies showed spherical shaped nanoparticles in the size of 22 nm in slightly agglomerated form. It was surprising that biogenic AgNPs showed cytotoxic effect against MCF-7 cell lines were confirmed by MTT, AO-EB, Hochest and COMET assays. There was an immediate induction of cellular damage in terms of loss of cell membrane integrity, oxidative stress and apoptosis were found in the cell which treated with AgNPs. This may be a first report on anti-MCF-7 property of biogenic AgNPs in the fourth generation of nanoparticles research. It is necessary to study the formulation and clinical trials to establish the nano drug to treat cancer cells.

An investigation on the cytotoxicity and caspase-mediated apoptotic effect of biologically synthesized silver nanoparticles using Podophyllum hexandrum on human cervical carcinoma cells

Now-a-days synthesis and characterization of silver nanoparticles (AgNPs) through biological entity is quite interesting to employ AgNPs for various biomedical applications in general and treatment of cancer in particular. This paper presents the green synthesis of AgNPs using leaf extract of Podophyllum hexandrum Royle and optimized with various parameters such as pH, temperature, reaction time, volume of extract and metal ion concentration for synthesis of AgNPs. TEM, XRD and FTIR were adopted for characterization. The synthesized nanoparticles were found to be spherical shaped with average size of 14 nm. Effects of AgNPs were analyzed against human cervical carcinoma cells by MTT Assay, quantification of ROS, RT-PCR and western blotting techniques. The overall result indicates that AgNPs can selectively inhibit the cellular mechanism of HeLa by DNA damage and caspase mediated cell death. This biological procedure for synthesis of AgNPs and selective inhibition of cancerous cells gives an alternative avenue to treat human cancer effectively.

In vitro antibacterial activity of ZnO and Nd doped ZnO nanoparticles against ESBL producing Escherichia coli and Klebsiella pneumoniae.

Pure ZnO and Neodymium (Nd) doped ZnO nanoparticles (NPs) were synthesized by the co-precipitation method. The synthesized nanoparticles retained the wurtzite hexagonal structure. From FESEM studies, ZnO and Nd doped ZnO NPs showed nanorod and nanoflower like morphology respectively. The FT-IR spectra confirmed the Zn-O stretching bands at 422 and 451 cm−1 for ZnO and Nd doped ZnO NPs respectively. From the UV-VIS spectroscopic measurement, the excitonic peaks were found around 373 nm and 380 nm for the respective samples. The photoluminescence measurements revealed that the broad emission was composed of ten different bands due to zinc vacancies, oxygen vacancies and surface defects. The antibacterial studies performed against extended spectrum β-lactamases (ESBLs) producing strains of Escherichia coli and Klebsiella pneumoniae showed that the Nd doped ZnO NPs possessed a greater antibacterial effect than the pure ZnO NPs. From confocal laser scanning microscopic (CLSM) analysis, the apoptotic nature of the cells was confirmed by the cell shrinkage, disorganization of cell wall and cell membrane and dead cell of the bacteria. SEM analysis revealed the existence of bacterial loss of viability due to an impairment of cell membrane integrity, which was highly consistent with the damage of cell walls.

Degradation of synthetic dye, Rhodamine B to environmentally non-toxic products using microalgae

In the present study a potential freshwater microalgae Coelastrella sp. was selected for degradation of synthetic dye, Rhodamine B in batch culture system. Effect of several physico-chemical parameters that influence the decolorization followed by degradation ability was investigated (inoculum concentration, initial dye concentration, temperature and pH) and optimal experimental condition was ascertained. The optimum operating conditions were found to be [Dye]=100 mg l(-1); [temperature]=30°C; with 10% of inoculum at a pH of 8. Under these conditions, a maximum of 80% decolorization of the dye was achieved in 20 days. Peroxidase activity of the isolate was also determined and it was found to be 2.1 μmol min mg(-1) of protein. The actual break down of the dye was confirmed by using various analytical techniques such as GC-MS, TLC, FTIR and UV-vis spectral analysis. Small aliphatic chains, small chain alcohols and ketones were obtained after degradation of Rhodamine B. These are the evidences that showed that microalgae play a vital role on dye degradation to non-toxic products effectively.

One pot synthesis and anti-biofilm potential of copper nanoparticles (CuNPs) against clinical strains of Pseudomonas aeruginosa

Pseudomonas aeruginosa, an opportunistic pathogen frequently associated with nosocomial infections, is emerging as a serious threat due to its resistance to broad spectrum antimicrobials. The biofilm mode of growth confers resistance to antibiotics and novel anti-biofilm agents are urgently needed. Nanoparticle based treatments and therapies have been of recent interest because of their versatile applications. This study investigates the anti-biofilm activity of copper nanoparticles (CuNPs) synthesized by the one pot method against P. aeruginosa. Standard physical techniques including UV–visible and Fourier transform infrared spectroscopy, X-ray diffraction and transmission electron microscopy were used to characterize the synthesized CuNPs. CuNP treatments at 100 ng ml−1 resulted in a 94, 89 and 92% reduction in biofilm, cell surface hydrophobicity and exopolysaccharides respectively, without bactericidal activity. Evidence of biofilm inhibition was also seen with light and confocal microscope analysis. This study highlights the anti-biofilm potential of CuNPs, which could be utilized as coating agents on surgical devices and medical implants to manage biofilm associated infections.

ANTIMICROBIAL DRUG RESISTANCE IN STRAINS OF Escherichia coli ISOLATED FROM FOOD SOURCES

A variety of foods and environmental sources harbor bacteria that are resistant to one or more antimicrobial drugs used in medicine and agriculture. Antibiotic resistance in Escherichia coli is of particular concern because it is the most common Gram-negative pathogen in humans. Hence this study was conducted to determine the antibiotic sensitivity pattern of E. coli isolated from different types of food items collected randomly from twelve localities of Hyderabad, India. A total of 150 samples comprising; vegetable salad, raw egg-surface, raw chicken, unpasteurized milk, and raw meat were processed microbiologically to isolate E. coli and to study their antibiotic susceptibility pattern by the Kirby-Bauer method. The highest percentages of drug resistance in isolates of E. coli were detected from raw chicken (23.3%) followed by vegetable salad (20%), raw meat (13.3%), raw egg-surface (10%) and unpasteurized milk (6.7%). The overall incidence of drug resistant E. coli was 14.7%. A total of six (4%) Extended Spectrum β-Lactamase (ESBL) producers were detected, two each from vegetable salads and raw chicken, and one each from raw egg-surface and raw meat. Multidrug resistant strains of E. coli are a matter of concern as resistance genes are easily transferable to other strains. Pathogen cycling through food is very common and might pose a potential health risk to the consumer. Therefore, in order to avoid this, good hygienic practices are necessary in the abattoirs to prevent contamination of cattle and poultry products with intestinal content as well as forbidding the use of untreated sewage in irrigating vegetables.

Gold nanoparticles from Pro and eukaryotic photosynthetic microorganisms—Comparative studies on synthesis and its application on biolabelling

Today, a material science focuses on the nanoparticles synthesis in general and synthesizing them by biological entity in particular for their marvel production and its remarkable property. In this present study, synthesis of gold nanoparticles using photosynthetic microorganisms such as Coelastrella sp. (eukaryotes) and Phormidium sp. (prokaryotes) were reacted with Chloroauric acid (HAuCl(4)) and bioaccumulation was assessed. Various techniques were adopted for characterization of nanoparticles and compared. It was found to be 25 nm sized nanotriangles and 30 nm sized spherical shaped nanoparticles were synthesized by prokaryotic and eukaryotic microorganisms respectively by TEM analysis. Biogenic gold nanoparticles have potent antioxidant property and the interaction of gold nanoparticles with DNA was evaluated that biogenic nanoparticles were actively bound to DNA in increased concentration. It was revealed that biogenic nanoparticles have wide range of applications depends on the biological entity used. Selection of suitable biological entity is very much important for the production of nanoparticles with desirable shapes and size for the biomedical applications.

Isolation and characterization of plant growth promoting endophytic bacteria and their effect on tomato ( Lycopersicon esculentum ) and chilli ( Capsicum annuum ) seedling growth

The endophytic bacteria known to reside in plant tissues have often been shown to promote plant growth. The present study deals with the efficacy of eight isolates of putative endophytes from surface-sterilized seeds of the crop plants tomato and chilli. Two isolates were Gram negative and six were Gram positive. All isolates were able to grow in up to 6% NaCl, and isolate BETL13 grew in up to 12% NaCl. The isolates were identified using a microbial identification system (Biolog). Of the eight isolates, six belong to the genus Bacillus and two are Serratia. The partial 16S rRNA gene sequences of BECS7, BETS14 shared 99% and 98% similarity with Bacillus sp. BETS11 showed 97% similarity to Bacillus subtilis and BECS1 showed 98% similarity to Arthrobacter sp. Under in vitro conditions, all eight isolates showed antagonistic activity against Sclerotium rolfsii, Fusarium oxysporum, Colletotrichum capsici and Pythium sp. The endophytes were also found to produce indole acetic acid and siderophore and four isolates solubilized inorganic phosphate. The plant growth promotion properties were demonstrated through a chilli- and tomato-based bioassay under greenhouse conditions. Isolates BETL13, BETL9, BECS1, BECL8 and BECS7 showed plant growth promotion in terms of an increase in root and shoot length and the number of secondary roots with respect to their host as well as in cross inoculation.