Browsing by Author "Vidya, S.M."

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Nisin gold nanoparticles assemble as potent antimicrobial agent against Enterococcus faecalis and Staphylococcus aureus clinical isolates
(2017) Pradeepa; Udaya, Bhat, K.; Vidya, S.M.
Enterococci and staphylococci have the potency to acquire resistant to antibiotics and have emerged as serious nosocomial pathogens responsible for various diseases. The continuous seeking of new antimicrobials against these pathogens is the only way to avoid the rapid spreading of diseases. Controlled fabrication of existing antimicrobials with nanoparticles offers an alternative strategy to combat against these pathogens with an effective manner. In the present study, gold nanoparticles (AuNPs) were functionalized with nisin to kill a wide range of clinically isolated Enterococcus faecalis and Staphylococcus aureus strains. Nisin functionalized gold nanoparticles (NAuNPs) exhibited good inhibitory activity against all seven multidrug resistant (MDR) and eight non-MDR E. faecalis and S. aureus strains. Minimum inhibitory concentration of NAuNPs was >8 32 fold lower than nisin. Interestingly, antibiotic resistant was not observed by these pathogens up to 8 generation. TEM and AFM investigation revealed that, the antimicrobial action of NAuNPs appears to act in three sequential stages: membrane destabilization, pore formation, followed by intracellular fluid leakage. In addition, NAuNPs were non toxic and showed less hemolytic activity. These findings indicated that, the NAuNPs can be served as an alternative antimicrobial agent to treat a wide range of enterococcal and staphylococcal infections. 2016 Elsevier B.V.
Nisin gold nanoparticles assemble as potent antimicrobial agent against Enterococcus faecalis and Staphylococcus aureus clinical isolates
(Editions de Sante editions.de.sante@wanadoo.fr, 2017) Pradeepa, n.; Bhat, K.U.; Vidya, S.M.
Enterococci and staphylococci have the potency to acquire resistant to antibiotics and have emerged as serious nosocomial pathogens responsible for various diseases. The continuous seeking of new antimicrobials against these pathogens is the only way to avoid the rapid spreading of diseases. Controlled fabrication of existing antimicrobials with nanoparticles offers an alternative strategy to combat against these pathogens with an effective manner. In the present study, gold nanoparticles (AuNPs) were functionalized with nisin to kill a wide range of clinically isolated Enterococcus faecalis and Staphylococcus aureus strains. Nisin functionalized gold nanoparticles (NAuNPs) exhibited good inhibitory activity against all seven multidrug resistant (MDR) and eight non-MDR E. faecalis and S. aureus strains. Minimum inhibitory concentration of NAuNPs was >8–32 fold lower than nisin. Interestingly, antibiotic resistant was not observed by these pathogens up to 8 generation. TEM and AFM investigation revealed that, the antimicrobial action of NAuNPs appears to act in three sequential stages: membrane destabilization, pore formation, followed by intracellular fluid leakage. In addition, NAuNPs were non toxic and showed less hemolytic activity. These findings indicated that, the NAuNPs can be served as an alternative antimicrobial agent to treat a wide range of enterococcal and staphylococcal infections. © 2016 Elsevier B.V.
Preparation of gold nanoparticles by novel bacterial exopolysaccharide for antibiotic delivery
(2016) Pradeepa; Vidya, S.M.; Mutalik, S.; Udaya, Bhat, K.; Huilgol, P.; Avadhani, K.
Aim To develop potent drug delivery agents to treat multidrug resistant (MDR) bacterial infections using gold nanoparticles (AuNPs) prepared by bacterial exopolysaccharide (EPS) being a reducing and stabilizing agent. Methods Gold nanoparticles were prepared by EPS, extracted from Lactobacillus plantarum. AuNPs were characterized by UV-visible spectrophotometer, transmission electron microscope (TEM), zeta potential and Fourier transform infrared spectroscopy. Antibiotics used for functionalization of AuNPs were levofloxacin, cefotaxime, ceftriaxone and ciprofloxacin. The resulted functionalized AuNPs were tested against various MDR bacteria by employing different assays such as well diffusion assay, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and time killing assay. Key findings The nanostructures exhibited excellent bactericidal activity and reduced MIC and MBC against MDR Gram positive and Gram negative bacteria compared to free drugs. Escherichia coli was the most susceptible MDR bacteria followed by Klebsiella pneumoniae and Staphylococcus aureus. TEM results revealed that the bactericidal activity of nanostructures could be mediated by penetration, loss of cytoplasmic contents and cell lysis. Significance Antibiotic functionalized nanostructures were more potent than free drugs and could be used as potent drug delivery vehicles. 2016 Elsevier Inc. All rights reserved.
Preparation of gold nanoparticles by novel bacterial exopolysaccharide for antibiotic delivery
(Elsevier Inc. usjcs@elsevier.com, 2016) Pradeepa, n.; Vidya, S.M.; Mutalik, S.; Bhat, K.U.; Huilgol, P.; Avadhani, K.
Aim To develop potent drug delivery agents to treat multidrug resistant (MDR) bacterial infections using gold nanoparticles (AuNPs) prepared by bacterial exopolysaccharide (EPS) being a reducing and stabilizing agent. Methods Gold nanoparticles were prepared by EPS, extracted from Lactobacillus plantarum. AuNPs were characterized by UV-visible spectrophotometer, transmission electron microscope (TEM), zeta potential and Fourier transform infrared spectroscopy. Antibiotics used for functionalization of AuNPs were levofloxacin, cefotaxime, ceftriaxone and ciprofloxacin. The resulted functionalized AuNPs were tested against various MDR bacteria by employing different assays such as well diffusion assay, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and time killing assay. Key findings The nanostructures exhibited excellent bactericidal activity and reduced MIC and MBC against MDR Gram positive and Gram negative bacteria compared to free drugs. Escherichia coli was the most susceptible MDR bacteria followed by Klebsiella pneumoniae and Staphylococcus aureus. TEM results revealed that the bactericidal activity of nanostructures could be mediated by penetration, loss of cytoplasmic contents and cell lysis. Significance Antibiotic functionalized nanostructures were more potent than free drugs and could be used as potent drug delivery vehicles. © 2016 Elsevier Inc. All rights reserved.