Evaluation of antibacterial efficacy of phyto fabricated silver nanoparticles using Mukia scabrella (Musumusukkai) against drug resistance nosocomial gram negative bacterial pathogens

Synthesis and Characterization of ZnO Nanoparticles Derived from Biomass (Sisymbrium Irio) and Assessment of Potential Anticancer Activity

Cancer treatment development is hampered by chemotherapy side effects, drug resistance, and tumor metastasis, giving cancer patients a gloomy prognosis. Nanoparticles (NPs) have developed as a promising medicinal delivery technique in the last 10 years. The zinc oxide (ZnO) NPs can precisely and captivatingly promote the apoptosis of cancer cells in cancer treatment. There is also an urgent need to discover novel anti-cancer therapies, and current research suggests that ZnO NPs hold significant promise. ZnO NPs have been tested for phytochemical screening and in vitro chemical efficiency. The green synthesis method was employed for the preparation of ZnO NPs from Sisymbrium irio (L.) (Khakshi). An alcoholic and aqueous extract of S. irio was prepared using the Soxhlet method. Various chemical compounds were revealed in the methanolic extract through qualitative analysis. The results of quantitative analysis showed that the total phenolic content has the highest amount (42.7861 mgGAE/g), while the resultant amounts of (5.72175 mgAAE/g) and (15.20725 mgAAE/g) were obtained in total flavonoid content and antioxidant property, respectively. ZnO NPs were prepared using a 1:1 ratio. The synthesized ZnO NPs were identified to have a hexagonal wurtzite crystal arrangement. The nanomaterial was characterized by scanning electron microscopy, transmission electron microscopy, and UV-visible spectroscopy. The ZnO-NPs' morphology exhibited an absorbance at 350-380 nm. Furthermore, different fractions were prepared and assessed for anticancer activity. As a result of this anticancer activity, all fractions exhibited cytotoxic activity against both BHK and HepG2 human cancer cell lines. The methanol fraction showed the highest activity of 90% (IC50 = 0.4769 mg/mL), followed by the hexane fraction that showed 86.72%, ethyl acetate showed 85%, and chloroform fraction showed 84% against BHK and HepG2 cell lines. These findings suggested that synthesized ZnO-NPs have anticancer potential.

Eco-friendly Green Synthesis of Silver Nanoparticles from Leaf Extract of Solanum khasianum: Optical Properties and Biological Applications

The green synthesis of silver nanoparticles (AgNPs) was considered to be efficacious over other approaches due to their eco-friendliness, cost-effectiveness, and high stability. The biosynthesis of AgNPs was achieved by the reduction of silver nitrate using the aqueous leaf extract of Solanum khasianum. The biosynthesized AgNPs were examined by a color change and UV-Vis spectroscopy with an absorption spectrum at 440 nm. The biomolecules existing in S. khasianum leaf extract accountable for bioreduction and capping of AgNPs were analyzed by FTIR analysis and confirmed the presence of alcohols, phenols, alkanes, carboxylic acid, nitro compounds, and amines. The crystalline nature of Sk-AgNPs with face-centered cubic lattice was confirmed by X-ray diffraction (XRD) spectrum. The average crystallite size of Sk-AgNPs was computed as 15.96 nm. The lattice constant, unit cell volume, and spacing values of Sk-AgNPs were parallel to the values indexed in the Joint Committee on Powder Diffraction Standard of silver (JCPDS-04-0783). Scanning electron microscope (SEM) imaging witnessed the spherical structure of synthesized AgNPs. Energy dispersive X-ray (EDX) spectrum acknowledged the AgNPs fabrication with strong signals of silver atoms at 3 keV energy. The biofabricated Sk-AgNPs showed a photoluminescence (PL) emission spectrum of 445 nm with an excitation at 330 nm. Sk-AgNPs showed considerable DPPH radical scavenging activity (87.98%) than BHT (86.14%) and also exhibited significant antidiabetic activity compared to acarbose. Sk-AgNPs revealed antibacterial potentiality against B. sphaericus, E. coli, S. aureus, and P. fluorescens. Moreover, Sk-AgNPs showed dose-dependent cytotoxicity against MCF-7 cell line. This method of green synthesis would support the eco-friendly fabrication of AgNPs from S. khasianum leaf extract with considerable therapeutic activities.

Recent advances in anticancer and antimicrobial activity of silver nanoparticles synthesized using phytochemicals and organic polymers

Development of eco-friendly synthetic methods has resulted in the production of biocompatible Ag NPs for applications in medical sector. To overcome the prevailing antibiotic resistance in bacteria, Ag NPs are being extensively researched over the past few years due to their broad spectrum and robust antimicrobial properties. Silver nanoparticles are also being studied widely in advanced anticancer therapy as an alternative anticancer agent to combat cancer in an effective manner. Keeping this backdrop in consideration, this review aims to provide an extensive coverage of the recent progresses in the green synthesis of Ag NPs specifically using plant derived reducing agents such phytochemicals and numerous other biopolymers. Current development in antimicrobial activity of Ag NPs against various pathogens has been deliberated at length. Recent advances in potent anticancer activity of the biogenic Ag NPs against various cancerous cell lines has also been discussed in detail. Mechanistic details of the synthesis of Ag NPs, their anticancer and antimicrobial action has also been highlighted.

Mechanistic aspects of plant-based silver nanoparticles against multi-drug resistant bacteria

Resistance among pathogenic bacteria to the existing antibiotics is one of the most alarming problems of the modern world. Alongwith reducing the use of antibiotics, and antibiotic stewardship, an alternative to antibiotics is much needed in the current scenario to combact infectious diseases. One alternative is to produce nanomaterials, especially, silver nanoparticles (AgNPs) against antibiotic-resistant bacteria. AgNPs are the most vital and fascinating nanoparticles because of their unique structural and functional properties and application against pathogenic bacteria. However, the synthesis of AgNPs remains a problem because of the chemicals and energy requirements and the byproducts of the reactions. Concerns have been raised about using chemically and physically synthesized nanoparticles because of their potential risks to the human body, animals, and environment. Green synthesis of these nanoparticles is a better alternative to physical and chemical approaches. Plant-based synthesis in turn is a method which can provide AgNPs that are cost-effective and eco-friendly as well as biocompatible. The specific features of size, morphology and shape of plant-based AgNPs give them the potency to fight multi-drug resistant bacteria. A detailed look into mechanistic aspects of the action of AgNPs against resistant bacteria with a focus on characteristic properties of AgNPs is required. This review discusses in detail these aspects and the potential of plant-based AgNPs as a solution to antibiotic resistance.

Cytotoxic, antioxidant, and antimicrobial activities of Celery (Apium graveolens L.)

Celery (Apium graveolens Linn, Family: Apiaceae) is a common edible herb used as a spice in the traditional medicine of several nations since time immemorial. The whole plant is extensively used in cooking as soups and salads. A. graveolens has various pharmacological properties such as anticancer, anti-obesity, anti-hepatotoxic, and antihypertensive agents. Hence, it is of interest to document the in vitro cytotoxic, antioxidant, and antimicrobial activity of A. graveolens. The plants were collected in the local market, shade dried, and different parts of the plants were extracted with 70% ethanol using a cold maceration process. Antioxidant tests were performed based on the various radical scavenging methods. Antimicrobial activity and MIC were completed using the respective cup-plate and two-fold serial dilution method. In vitro cytotoxic studies were achieved by the MTT; Sulphorhodamine B assayed total cell protein content. DLA and ESC cells determined the short-term toxicity. The leaf extract exhibited significant antioxidant properties against NO, DPPH, ABTS, LPO, and HPO methods. Thus, potential inhibition against Gram-positive, Gram-negative, and fungal strains within the MIC ranges of 250-500 µg/ml was observed. All the extracts of the plant presented in the study revealed greater cytotoxicity effects against five respective cancer cell lines, L6, Vero, BRL 3A, A-549, L929, and L-929 with the ranging of 443-168.5 µg/ml. Thus, we show that A. graveolens possess a potential cytotoxic, antioxidant, and antimicrobial activity.

Antibiotics in Food Chain: The Consequences for Antibiotic Resistance

Antibiotics have been used as essential therapeutics for nearly 100 years and, increasingly, as a preventive agent in the agricultural and animal industry. Continuous use and misuse of antibiotics have provoked the development of antibiotic resistant bacteria that progressively increased mortality from multidrug-resistant bacterial infections, thereby posing a tremendous threat to public health. The goal of our review is to advance the understanding of mechanisms of dissemination and the development of antibiotic resistance genes in the context of nutrition and related clinical, agricultural, veterinary, and environmental settings. We conclude with an overview of alternative strategies, including probiotics, essential oils, vaccines, and antibodies, as primary or adjunct preventive antimicrobial measures or therapies against multidrug-resistant bacterial infections. The solution for antibiotic resistance will require comprehensive and incessant efforts of policymakers in agriculture along with the development of alternative therapeutics by experts in diverse fields of microbiology, biochemistry, clinical research, genetic, and computational engineering.

Efficacy and Mechanisms of Flavonoids against the Emerging Opportunistic Nontuberculous Mycobacteria

Nontuberculous mycobacteria (NTM) are the causative agent of severe chronic pulmonary diseases and is accountable for post-traumatic wound infections, lymphadenitis, endometritis, cutaneous, eye infections and disseminated diseases. These infections are extremely challenging to treat due to multidrug resistance, which encompasses the classical and existing antituberculosis agents. Hence, current studies are aimed to appraise the antimycobacterial activity of flavonoids against NTM, their capacity to synergize with pharmacological agents and their ability to block virulence. Flavonoids have potential antimycobacterial effects at minor quantities by themselves or in synergistic combinations. A cocktail of flavonoids used with existing antimycobacterial agents is a strategy to lessen side effects. The present review focuses on recent studies on naturally occurring flavonoids and their antimycobacterial effects, underlying mechanisms and synergistic effects in a cocktail with traditional agents.

Silver/silver chloride (Ag/AgCl) nanoparticles synthesized from Azadirachta indica lalex and its antibiofilm activity against fluconazole resistant Candida tropicalis

In this study, latex of Azadirachta indica was used for the synthesis of silver nanoparticles (AgNP). UV-visible spectroscopy revealed the formation of AgNPs and the absorption band optimized at 442 nm. Fourier transform infrared (FTIR) spectroscopy shows different functional groups (carboxyl, amine and hydroxyl) of biomolecule which are responsible for reduction and capping process. X-ray diffraction (XRD) analysis confirms the nanoparticles are crystalline silver and cubic (AgCl) with face-centered cubic (Ag) types. Electron microscopics (SEM and TEM) were used to characterize the shape and size of the nanoparticles. The anticandidal and antibiofilm activity of AgNPs was using Fluconazole resistant clinical isolate of Candida tropicalis. The new approach of plant-mediated AgNPs synthesis appears to be cost-effective, eco-friendly and easy methods. The synthesized AgNPs considered as a novel and alternative agent to prevent C. tropicalis biofilms.

One-step Synthesis of Silver Nanoparticles Using Saudi Arabian Desert Seasonal Plant Sisymbrium irio and Antibacterial Activity Against Multidrug-Resistant Bacterial Strains

Globally, antimicrobial resistance has grown at an alarming rate. To combat the multidrug-resistant (MDR) superbugs, silver nanoparticles (Ag NPs) were synthesized using an aqueous leaf extract of seasonal desert plant Sisymbrium irio obtained from the central region of Saudi Arabia by a simple one-step procedure. The physical and chemical properties of the Ag NPs were investigated through ultraviolet visisble analysis (UV-vis), Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM) analysis. The UV-vis spectrum showed an absorption band at 426 nm. The XRD results showed a highly crystalline face-centered cubic structure. The surface morphology analyzed using SEM and TEM analyses showed the particle size to be in the range 24 nm to 50 nm. Various concentrations of Ag NPs were tested against MDR Pseudomonas aeruginosa and Acinetobacter baumanii that cause ventilator-associated pneumonia (VAP). American Type Culture Collection (ATCC) Escherichia coli-25922 was used as the reference control strain. The Ag NPs effectively inhibited tested pathogens, even at the lowest concentration (6.25 µg) used. The bacterial inhibitory zone ranged from 11–21 mm. In conclusion, the newly synthesized Ag NPs could be a potential alternative candidate in biomedical applications in controlling the spread of MDR pathogens.

A review of the antimicrobial potential of precious metal derived nanoparticle constructs

The field of nanotechnology is rapidly growing. The promise of pharmacotherapeutics emerging from this vast field has drawn the attention of many researchers. However, with the increase in the prevalence of antibiotic resistant microorganisms, the manifestations of these promises are needed now more than ever. Many have postulated the antimicrobial potential of nanoparticle constructs derived from precious metals/noble metals nanoparticles (NMNPs), such as silver nanoparticles that show activity against multidrug resistant bacteria. In this review we will evaluate the current studies and explore the data to obtain a clear picture of the potential of these particles and the validity of the claims of drug resistant treatments with NMNPs.

Corn cob silica as an antibacterial support for silver nanoparticles: efficacy on Escherichia coli and Listeria monocytogenes

There is great potential to combine bioresource and recycled materials with nanotechnology for industrial and environmental applications. In a novel approach, silver (Ag) nanoparticles (Ag NPs) were imbedded on amine-functionalized silica obtained from corn cob (ACCS) to produce a composite material that can be used to inactivate bacteria. Transmission electron microscope (TEM) images show near-uniform ACCS particles (34.7 ± 8.6 nm diameter), with Ag NPs (5-10 nm diameter) homogenously dispersed on the surfaces. The potential of ACCS-Ag NPs to rapidly inactivate gram-negative Escherichia coli ATCC 8739 and gram-positive Listeria monocytogenes was investigated. A four-log (> 99.99%) inactivation of the E. coli was achieved within 30 min with 4 mg of ACCS-Ag NPs in a 40-mL PBS suspension (1 × 10⁵ CFU/mL). Extended exposure of ACCS-Ag NP may be required to inactivate L. monocytogenes, suggesting the ACCS-Ag NP composite will be less practical for gram-positive bacteria due to thick cell wall and alternative formulations may need to be developed. Result shows that the potential of corn cob silica as an alternative, eco-friendly support matrix for applications such as bacterial inactivation. The Ag-imbedded, amine-functionalized corn cob silica demonstrates how bio-waste can be combined with nanotechnology to produce useful materials.

Biogenic Nanosilver against Multidrug-Resistant Bacteria (MDRB)

Multidrug-resistant bacteria (MDRB) are extremely dangerous and bring a serious threat to health care systems as they can survive an attack from almost any drug. The bacteria's adaptive way of living with the use of antimicrobials and antibiotics caused them to modify and prevail in hostile conditions by creating resistance to known antibiotics or their combinations. The emergence of nanomaterials as new antimicrobials introduces a new paradigm for antibiotic use in various fields. For example, silver nanoparticles (AgNPs) are the oldest nanomaterial used for bactericide and bacteriostatic purposes. However, for just a few decades these have been produced in a biogenic or bio-based fashion. This review brings the latest reports on biogenic AgNPs in the combat against MDRB. Some antimicrobial mechanisms and possible silver resistance traits acquired by bacteria are also presented. Hopefully, novel AgNPs-containing products might be designed against MDR bacterial infections.

Functionalization of silver nanoparticles with mPEGylated luteolin for selective visual detection of Hg2+ in water sample

A novel colorimetric sensor for selective detection of Hg²⁺ based on mPEGylated luteolin functionalized silver nanoparticles was prepared.

Phytochemical constituents of fucoidan (Padina tetrastromatica) and its assisted AgNPs for enhanced antibacterial activity

Biological synthesis of nanomaterials is a growing innovative approach and it was broadly utilised in the field of nanotechnology and nanomedicine. This study illustrates that biosynthesis of silver nanoparticles (AgNPs) using fucoidan extracted from seaweed Padina tetrastromatica. The functional groups of extracted fucoidan were characterised by Fourier transform infrared spectroscopy (FTIR) and used to NPs synthesis. Synthesised AgNPs were characterised by ultraviolet-visible spectra, scanning electron microscope, energy dispersive X-ray, transmission electron microscope, selected area electron diffraction and FTIR. In this study, their main focus is enhancement antibacterial activity of AgNPs coated antibiotics against antibiotic resistant bacteria. Among the microorganisms, Serratia nematodiphila was resistant to novobiocin and penicillin, but it was sensitive to AgNPs impregnated antibiotic discs. The zone of inhibition was 12 and 15 mm. The synergistic effect of combined antibiotics and AgNPs resulted in increased fold area which was greater than the sum of their separate effects. It reveals that AgNPs are highly sought in the medicinal field due to their broad spectrum of antibacterial activity and relatively cheaper. This enhanced synergistic effect potentially superior to control the growth of bacteria and it is the budding process for the development of new remedial agents for severe diseases.

Synthesis of gold and silver nanoparticles using Mukia maderaspatna plant extract and its anticancer activity

The present investigation reveals the in vitro cytotoxic effect of the biosynthesised metal nanoparticles on the MCF 7 breast cancer cell lines. The gold and silver nanoparticles were synthesised through an environmentally admissible route using the Mukia Maderaspatna plant extract. Initially, the biomolecules present in the plant extract were analysed using phytochemical analysis. Further, these biomolecules reduce the metal ion solution resulting from the formation of metal nanoparticles. The reaction parameters were optimised to control the size of nanoparticles which were confirmed by UV visible spectroscopy. Various instrumental techniques such as Fourier transform-infrared spectroscopy, high resolution transmission electron microscopy, energy dispersive X-ray and scanning electron microscopy were employed to characterise the synthesised gold and silver nanoparticles. The synthesised gold and silver nanoparticles were found to be 20-50 nm and were of different shapes including spherical, triangle and hexagonal. MTT and dual staining assays were carried out with different concentrations (1, 10, 25, 50 and 100 µg/ml) of gold and silver nanoparticles. The results show that the nanoparticles exhibited significant cytotoxic effects with IC 50 value of 44.8 µg/g for gold nanoparticles and 51.3 µg/g for silver nanoparticles. The observations in this study show that this can be developed as a promising nanomaterial in pharmaceutical and healthcare sector.

A highly efficient, low-toxic, wide-spectrum antibacterial coating designed for 3D printed implants with tailorable release properties

A broad spectrum antibacterial coatings with tailorable release properties were developed for 3D printed implants.

Silver Nanoforms as a Therapeutic Agent for Killing Escherichia coli and Certain ESKAPE Pathogens

The scope of this study included the preparation of silver nanoforms with high antimicrobial efficacy, low cost, and ease of application. The term 'silver nanoforms' refers to silver located on the amorphous or crystalline titanium dioxide (TiO2). Silver nanoforms may be used as an alternative to antibiotics in killing bacteria. Pure and silver-incorporated titanium (used as a carrier) was prepared using the sol-gel-modified method. Physical and chemical properties of the samples were described, and the antibacterial activity was indicated using the following strains of bacteria: Staphylococcus aureus, Klebsiella pneumoniae (ESKAPE pathogens), and Escherichia coli. The results have shown that the antibacterial activity of silver nanoforms with amorphous TiO2 is much better than that in the samples based on anatase (crystalline TiO2). The sensitivity of the tested bacteria to silver nanoforms depends on physical and chemical properties of the nanoforms and individual characteristics of the bacteria. For the first time, significant participation of amorphous TiO2 in antibacterial compounds has been described through this study.

Antidiabetic activity of silver nanoparticles from green synthesis using Lonicera japonica leaf extract

In this work we report the green synthesis of silver nanoparticles (AgNPs) using the aqueous leaf extract of Lonicera japonica.

Synthesis and characterization of magnetite/silver/antibiotic nanocomposites for targeted antimicrobial therapy

The article is devoted to preparation and characterization of magnetite/silver/antibiotic nanocomposites for targeted antimicrobial therapy. Magnetite nanopowder was produced by thermochemical technique; silver was deposited on the magnetite nanoparticles in the form of silver clusters. Magnetite/silver nanocomposite was investigated by XRD, SEM, TEM, AFM, XPS, EDX techniques. Adsorptivity of magnetite/silver nanocomposite towards seven antibiotics from five different groups was investigated. It was shown that rifampicin, doxycycline, ceftriaxone, cefotaxime and doxycycline may be attached by physical adsorption to magnetite/silver nanocomposite. Electrostatic surfaces of antibiotics were modeled and possible mechanism of antibiotic attachment is considered in this article. Raman spectra of magnetite, magnetite/silver and magnetite/silver/antibiotic were collected. It was found that it is difficult to detect the bands related to antibiotics in the magnetite/silver/antibiotic nanocomposite spectra due to their overlap by the broad carbon bands of magnetite nanopowder. Magnetic measurements revealed that magnetic saturation of the magnetite/silver/antibiotic nanocomposites decreased on 6-19 % in comparison with initial magnetite nanopowder. Pilot study of antimicrobial properties of the magnetite/silver/antibiotic nanocomposites were performed towards Bacillus pumilus.

Biosynthesis of silver fine particles and particles decorated with nanoparticles using the extract of Illicium verum (star anise) seeds

Given the upsurge of new technologies based on nanomaterials, the development of sustainable methods to obtain functional nanostructures has become an imperative task. In this matter, several recent researches have shown that the biodegradable natural antioxidants of several plant extracts can be used simultaneously as reducing and stabilizing agents in the wet chemical synthesis of metallic nanoparticles, opening new opportunities to design greener synthesis. However, the challenge of these new techniques is to produce stable colloidal nanoparticles with controlled particle uniformity, size, shape and aggregation state, in similar manner than the well-established synthetic methods. In the present work, colloidal metallic silver nanoparticles have been synthesized using silver nitrate and extracts of Illicium verum (star anise) seeds at room temperature in a facile one-step procedure. The resulting products were colloidal suspensions of two populations of silver nanoparticles, one of them with particle sizes of few nanometers and the other with particles of tens of nm. Strikingly, the variation of the AgNO3/extract weight ratio in the reaction medium yielded to the variation of the spatial distribution of the nanoparticles: high AgNO3/extract concentration ratios yielded to randomly dispersed particles, whereas for lower AgNO3/extract ratios, the biggest particles appeared coated with the finest nanoparticles. This biosynthesized colloidal system, with controlled particle aggregation states, presents plasmonic and SERS properties with potential applications in molecular sensors and nanophotonic devices.

Biosynthesis of Silver Nanoparticles and Its Applications

Silver nanoparticles possess unique properties which find myriad applications such as antimicrobial, anticancer, larvicidal, catalytic, and wound healing activities. Biogenic syntheses of silver nanoparticles using plants and their pharmacological and other potential applications are gaining momentum owing to its assured rewards. This critical review is aimed at providing an insight into the phytomediated synthesis of silver nanoparticles, its significant applications in various fields, and characterization techniques involved.

Comparison of the effects of silver phosphate and selenium nanoparticles on Staphylococcus aureus growth reveals potential for selenium particles to prevent infection

Interactions of silver phosphate nanoparticles (SPNPs) and selenium nanoparticles (SeNPs) with Staphylococcus aureus cultures have been studied at the cellular, molecular and protein level. Significant antibacterial effects of both SPNPs and SeNPs on S. aureus were observed. At a concentration of 300 μM, SPNPs caused 37.5% inhibition of bacterial growth and SeNPs totally inhibited bacterial growth. As these effects might have been performed due to the interactions of nanoparticles with DNA and proteins, the interaction of SPNPs or SeNPs with the amplified zntR gene was studied. The presence of nanoparticles decreased the melting temperatures of the nanoparticle complexes with the zntR gene by 23% for SeNPs and by 12% for SPNPs in comparison with the control value. The concentration of bacterial metallothionein was 87% lower in bacteria after application of SPNPs (6.3 μg mg(-1) protein) but was increased by 29% after addition of SeNPs (63 μg mg(-1) protein) compared with the S. aureus control (49 μg mg(-1) protein). Significant antimicrobial effects of the nanoparticles on bacterial growth and DNA integrity provide a promising approach to reducing the risk of bacterial infections that cannot be controlled by the usual antibiotic treatments.

Green synthesis of silver nanoparticles by Chrysanthemum morifolium Ramat. extract and their application in clinical ultrasound gel

Eco-friendly green synthesis with plant extracts plays a very important role in nanotechnology, without any harmful chemicals. In this report, the synthesis of water-soluble silver nanoparticles was developed by treating silver ions with Chrysanthemum morifolium Ramat. extract at room temperature. The effect of the extract on the formation of silver nanoparticles was characterized by ultraviolet and visible absorption spectroscopy, X-ray diffraction, transmission electron microscopy, and Fourier transform infrared spectroscopy. The ultraviolet and visible absorption spectroscopy results show a strong resonance centered on the surface of silver nanoparticles (AgNP) at 430 nm. The Fourier transform infrared spectroscopy spectral study demonstrates Chrysanthemum morifolium Ramat. extract acted as the reducing and stabilizing agent during the synthesis. The X-ray diffraction analysis confirmed that the synthesized AgNP are single crystallines, corresponding with the result of transmission electron microscopy. Water-soluble AgNP, with an approximate size of 20 nm–50 nm were also observed in the transmission electron microscopy image. The bactericidal properties of the synthesized AgNP were investigated using the agar-dilution method and the growth-inhibition test. The results show the AgNP had potent bactericidal activity on Staphylococcus aureus and Escherichia coli, as well as a strong antibacterial activity against gram-negative bacteria, as compared to gram-positive bacteria with a dose-dependent effect, thus providing a clinical ultrasound gel with bactericidal property for prevention of cross infections.