Synthesized AgNPs are readily available in solution with high density and are stable. Among several natural sources, plant and plant products
are available easily, and it facilitates synthesis of nanoparticles fairly rapidly. In addition, leaf extracts contain alkaloids, tannin, steroids, phenol, saponins, and flavonoids in aqueous extracts. On the basis of these compounds found in the extracts, we expect that the proteins or polysaccharides or secondary GSK1210151A chemical structure metabolites of leaf extracts can reduce the Ag+ ions to Ag0 state and form silver nanoparticles. In recent years, various plants have been explored for synthesis of silver and gold nanoparticles. Recently, Singhal et al.  synthesized silver nanoparticles using Ocimum see more sanctum leaf extract showed significant antibacterial activity against E. coli and Staphylococcus aureus. Although several studies have reported the antibacterial activity of silver nanoparticles, the combination of silver nanoparticles and
antibiotics studies are warranted. The increasing prevalence of microbial resistance has made the management of public health an important issue in the modern world. Although several new antibiotics were developed AZD0530 supplier in the last few decades, none have improved activity against multidrug-resistant bacteria . Therefore, it is important to develop alternate and more effective therapeutic strategies to treat Gram-negative and Gram-positive pathogens. Nanoparticles, which have been used successfully for the delivery of therapeutic agents , in diagnostics for chronic diseases , and treatment of bacterial infections in skin and burn
wounds, are one option . AgNPs possess antibacterial [11, 12], anti-fungal , anti-inflammatory , anti-viral , anti-angiogenic , and anti-cancer activities [17, 18]. Developing AgNPs as a new generation of antimicrobial agents may be an attractive and cost-effective means to overcome Tyrosine-protein kinase BLK the drug resistance problem seen with Gram-negative and Gram-positive bacteria. The first aim of the present study was to develop a simple and environmentally friendly approach for the synthesis and characterization of AgNPs using Allophylus cobbe. The second aim of this study involved systematically analyzing the antibacterial and anti-biofilm activities of the biologically prepared AgNPs against a panel of human pathogens, including Pseudomonas aeruginosa, Shigella flexneri, Staphylococcus aureus, and Streptococcus pneumoniae. The effects of combining antibiotics with AgNPs against Gram-negative and Gram-positive bacteria were also investigated. Methods Bacterial strains and reagents Mueller Hinton broth (MHB) or Mueller Hinton agar (MHA), silver nitrate and ampicillin, chloramphenicol, erythromycin, gentamicin, tetracycline, and vancomycin antibiotics were purchased from Sigma-Aldrich (St. Louis, MO, USA).