A green synthesis of silver nanoparticles (AgNPs) was conducted using the stem extract of Piper chaba, which is a plant abundantly growing in South and Southeast Asia. The synthesis was carried out at different reaction conditions, i.e., reaction temperature, concentrations of the extract and silver nitrate, reaction time, and pH. The synthesized AgNPs were characterized by visual observation, ultraviolet–visible (UV-vis) spectroscopy, dynamic light scattering (DLS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray diffraction (XRD), energy dispersive x-ray (EDX), and Fourier transform infrared (FTIR) spectroscopy. The characterization results revealed that AgNPs were uniformly dispersed and exhibited a moderate size distribution. They were mostly spherical crystals with face-centered cubic structures and an average size of 19 nm. The FTIR spectroscopy and DLS analysis indicated that the phytochemicals capping the surface of AgNPs stabilize the dispersion through anionic repulsion. The synthesized AgNPs effectively catalyzed the reduction of 4-nitrophenol (4-NP) and degradation of methylene blue (MB) in the presence of sodium borohydride.

Biogenically synthesized silver nanoparticles (AgNP) increase the fascination over chemical ones due to their facile and green synthetic process. This study reports the development of an eco-friendly and cost-effective synthesis of AgNPs using an aqueous extract of Citrus macroptera fruit peel, an agricultural waste, as a sole agent with both reducing and capping abilities. The formation of AgNPs was verified by the surface plasmon resonance peak at 426 nm in the UV−vis spectrum, X-ray diffraction pattern, and transmission electron micrography images. The AgNPs obtained under the optimized conditions consist of face-centered cubic crystals and spherical morphology with an average size of 11 nm. The AgNPs are coated with phytochemicals in the C. macroptera fruit peel extract and are stably dispersible due to their negatively charged nature. The AgNPs effectively catalyzed the reduction of 4-nitrophenol to 4-aminophenol and the degradation of methyl orange and methylene blue in the presence of sodium borohydride. This method employing a fruit peel extract is facile, efficient, eco-friendly, and cost-effective and has potential for industrial green fabrication of AgNPs.

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Abstract-Aims:Because of uncontrolled and widespread use of antibiotics, the resistance pattern of uropathogens is changing drastically, specifically in developing countries, such as Bangladesh. The aim of the study was to identify the common Urinary Tract Infection (UTI) causing pathogens in the city of Jessore, Bangladesh and to check the performance of available antibiotics used by those patients. Study Design: Random 100 UTI patients who exhibited general UTI symptoms were included in our cross-sectional study. A medical proforma was prepared to input the information associated with the experiment including symptoms of patient's age, sex, laboratory diagnosis and antimicrobial susceptibility. Place and Duration of Study: Department of Microbiology, University of Science and Technology, Jessore 7408 and Pharmacy Discipline, Life Science School, Khulna University, Khulna 9208, Bangladesh, between June 2013 and July 2014.Methodology:Urine samples from 100 suspicious urinary tract infected patients were collected as described by Thomson and Miller. Bacterial isolates were tested to identify the bacterial species and to evaluate their antimicrobial susceptibility by Kirby-Bauer disk diffusion technique against some common antibiotics. Epidata® computer program 3.1 and SPSS version 16 statistical software used for confidence interval (CI) and P value, which were defined as P value is <0.05 and CI was set at 95% level of significance for all the proportions.Results: Among 100 samples, 74 samples showed positive for cultures adversely responsible for UTIs. About five different species of uropathogenswere identified from 74 cases. Comparative prevalence ofE. coli was detected in 69 of the 100 samples (69%), while Staphylococcus spp was found in 18 samples (18%), Pseudomonas aeruginosa in 8 samples (8%), and Klebsiella pneumoniae in 6 samples (6%), respectively. Comparative antibiotic resistance profile showed that most of the strains were highly resistant to Amoxicillin (85.14%) and Cotrimoxazole (81.08%). On the contrary, the strains showed significant sensitivity to Amikacin (94.59%), Azithromycin (93.24%), Doxycycline (90.54%), and Ceftriaxone (89.18%), respectively showed significant sensitivity. Conclusion: Our results could be helpful to compel rational antibiotic use for UTI. High resistance of uropathogens to antibiotics, such as Amoxicillin and Cotrimoxaxole, has been observed in a significant number of patients in the developing world, such as Bangladesh. Our studies may provoke further investigations into the mechanisms of antibiotic resistance of particular microbes.

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