scholarly journals Antibacterial Effect of Silver Nanoparticles Synthesized Using Murraya koenigii (L.) against Multidrug-Resistant Pathogens

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Faizan Abul Qais ◽  
Anam Shafiq ◽  
Haris M. Khan ◽  
Fohad M. Husain ◽  
Rais A. Khan ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Bacterial Infections ◽  
Enteric Bacteria ◽  
Multidrug Resistant ◽  
Murraya Koenigii ◽  
E Coli ◽  
Vis Spectroscopy ◽  
Zones Of Inhibition

Development of multidrug resistance among pathogens has become a global problem for chemotherapy of bacterial infections. Extended-spectrum β-lactamase- (ESβL-) producing enteric bacteria and methicillin-resistant Staphylococcus aureus (MRSA) are the two major groups of problematic MDR bacteria that have evolved rapidly in the recent past. In this study, the aqueous extract of Murraya koenigii leaves was used for synthesis of silver nanoparticles. The synthesized MK-AgNPs were characterized using UV-vis spectroscopy, FTIR, XRD, SEM, and TEM, and their antibacterial potential was evaluated on multiple ESβL-producing enteric bacteria and MRSA. The nanoparticles were predominantly found to be spheroidal with particle size distribution in the range of 5–20 nm. There was 60.86% silver content in MK-AgNPs. Evaluation of antibacterial activity by the disc-diffusion assay revealed that MK-AgNPs effectively inhibited the growth of test pathogens with varying sized zones of inhibition. The MICs of MK-AgNPs against both MRSA and methicillin-sensitive S. aureus (MSSA) strains were 32 μg/ml, while for ESβL-producing E. coli, it ranged from 32 to 64 μg/ml. The control strain of E. coli (ECS) was relatively more sensitive with an MIC of 16 μg/ml. The MBCs were in accordance with the respective MICs. Analysis of growth kinetics revealed that the growth of all tested S. aureus strains was inhibited (∼90%) in presence of 32 μg/ml of MK-AgNPs. The sensitive strain of E. coli (ECS) showed least resistance to MK-AgNPs with >81% inhibition at 16 μg/ml. The present investigation revealed an encouraging result on in vitro efficacy of green synthesized MK-AgNPs and needed further in vivo assessment for its therapeutic efficacy against MDR bacteria.

scholarly journals Silver Nanoparticles and Their Antibacterial Applications

2021 ◽  
Vol 22 (13) ◽  
pp. 7202
Author(s):  
Tamara Bruna ◽  
Francisca Maldonado-Bravo ◽  
Paul Jara ◽  
Nelson Caro
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Agents ◽  
Multidrug Resistant ◽  
Secondary Effects ◽  
Cytotoxic Effects ◽  
Factors Affecting ◽  
Gram Positive Bacteria ◽  
Resistant Strains

Silver nanoparticles (AgNPs) have been imposed as an excellent antimicrobial agent being able to combat bacteria in vitro and in vivo causing infections. The antibacterial capacity of AgNPs covers Gram-negative and Gram-positive bacteria, including multidrug resistant strains. AgNPs exhibit multiple and simultaneous mechanisms of action and in combination with antibacterial agents as organic compounds or antibiotics it has shown synergistic effect against pathogens bacteria such as Escherichia coli and Staphylococcus aureus. The characteristics of silver nanoparticles make them suitable for their application in medical and healthcare products where they may treat infections or prevent them efficiently. With the urgent need for new efficient antibacterial agents, this review aims to establish factors affecting antibacterial and cytotoxic effects of silver nanoparticles, as well as to expose the advantages of using AgNPs as new antibacterial agents in combination with antibiotic, which will reduce the dosage needed and prevent secondary effects associated to both.

scholarly journals Evaluation of the Efficacy of a Bacteriophage in the Treatment of Pneumonia Induced by Multidrug ResistanceKlebsiella pneumoniaein Mice

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Fang Cao ◽  
Xitao Wang ◽  
Linhui Wang ◽  
Zhen Li ◽  
Jian Che ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Burst Size ◽  
Multidrug Resistant ◽  
Lung Lesion ◽  
Lytic Bacteriophage ◽  
Short Latent Period ◽  
Dose Dependent ◽  
Antibiotic Control

Multidrug-resistantKlebsiella pneumoniae(MRKP) has steadily grown beyond antibiotic control. However, a bacteriophage is considered to be a potential antibiotic alternative for treating bacterial infections. In this study, a lytic bacteriophage, phage 1513, was isolated using a clinical MRKP isolate KP 1513 as the host and was characterized. It produced a clear plaque with a halo and was classified as Siphoviridae. It had a short latent period of 30 min, a burst size of 264 and could inhibit KP 1513 growthin vitrowith a dose-dependent pattern. Intranasal administration of a single dose of 2 × 109 PFU/mouse 2 h after KP 1513 inoculation was able to protect mice against lethal pneumonia. In a sublethal pneumonia model, phage-treated mice exhibited a lower level ofK. pneumoniaeburden in the lungs as compared to the untreated control. These mice lost less body weight and exhibited lower levels of inflammatory cytokines in their lungs. Lung lesion conditions were obviously improved by phage therapy. Therefore, phage 1513 has a great effectin vitroandin vivo, which has potential to be used as an alternative to an antibiotic treatment of pneumonia that is caused by the multidrug-resistantK. pneumoniae.

scholarly journals Synthesis of silver nanoparticles from extracts of Scytonema geitleri HKAR-12 and their in vitro antibacterial and antitumor potentials

2019 ◽  
Vol 8 (3) ◽  
pp. 576-585
Keyword(s):  
Silver Nanoparticles ◽  
Coli Strain ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
E Coli ◽  
Vis Spectroscopy ◽  
Shape Structure ◽  
Actual Size

In the present study silver nanoparticles (AgNPs) have been synthesized through the cell-free extracts of the rooftop dwelling cyanobacterium Scytonema geitleri HKAR-12. UV-VIS spectroscopy, FTIR, X-ray diffraction, SEM and TEM were used for the determination of morphological, structural and optical properties of synthesized AgNPs. Extracts of Scytonema geitleri HKAR-12 have the ability to reduce AgNO3 to Ag0. Sharp peak at 422 nm indicated the rapid synthesis of AgNPs. FTIR results showed the presence of different groups responsible for the reduction of AgNO3 to AgNPs. XRD pattern confirmed the crystalline nature of AgNPs. SEM showed the bead shape structure of AgNPs. TEM confirmed the actual size of AgNPs to be ranging between 9-17 nm. AgNPs showed antibacterial activity against Pseudomonas aeruginosa, Escherichia coli strain1 and E. coli strain 2 and 11 μg/mL of AgNPs effectively inhibited the growth of MCF-7 cells. Hence, Scytonema geitleri HKAR-12, isolated from the rooftop could serve as a desirable biological candidate for convenient and cheap production of AgNPs having antimicrobial and anti-cancerous properties.

scholarly journals In Vitro and In Vivo Antibacterial Activities of SM-216601, a New Broad-Spectrum Parenteral Carbapenem

2005 ◽  
Vol 49 (10) ◽  
pp. 4185-4196 ◽  
Author(s):  
Yutaka Ueda ◽  
Katsunori Kanazawa ◽  
Ken Eguchi ◽  
Koji Takemoto ◽  
Yoshiro Eriguchi ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Antibacterial Activities ◽  
Multiresistant Pathogens ◽  
E Coli ◽  
Wide Range ◽  
Agar Dilution ◽  
Resistant Strains ◽  
Mrsa Strains

ABSTRACT SM-216601 is a novel parenteral 1β-methylcarbapenem. In agar dilution susceptibility testing, the MIC of SM-216601 for 90% of the methicillin-resistant Staphylococcus aureus (MRSA) strains tested (MIC90) was 2 μg/ml, which was comparable to those of vancomycin and linezolid. SM-216601 was also very potent against Enterococcus faecium, including vancomycin-resistant strains (MIC90 = 8 μg/ml). SM-216601 exhibited potent activity against penicillin-resistant Streptococcus pneumoniae, ampicillin-resistant Haemophilus influenzae, Moraxella catarrhalis, Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis, with MIC90s of less than 0.5 μg/ml, and intermediate activity against Citrobacter freundii, Enterobacter cloacae, Serratia marcescens, and Pseudomonas aeruginosa. The therapeutic efficacy of SM-216601 against experimentally induced infections in mice caused by S. aureus, E. faecium, E. coli, and P. aeruginosa reflected its in vitro activity and plasma level. Thus, SM-216601 is a promising candidate for nosocomial bacterial infections caused by a wide range of gram-positive and gram-negative bacteria, including multiresistant pathogens.

scholarly journals Clavanin A Improves Outcome of Complications from Different Bacterial Infections

2014 ◽  
Vol 59 (3) ◽  
pp. 1620-1626 ◽  
Author(s):  
Osmar N. Silva ◽  
Isabel C. M. Fensterseifer ◽  
Elaine A. Rodrigues ◽  
Hortência H. S. Holanda ◽  
Natasha R. F. Novaes ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Bacterial Infections ◽  
Multidrug Resistant ◽  
Toxicity Tests ◽  
Cytotoxic Activities ◽  
Content Type ◽  
Wound Model ◽  
Acute Toxicity Tests

ABSTRACTThe rapid increase in the incidence of multidrug-resistant infections today has led to enormous interest in antimicrobial peptides (AMPs) as suitable compounds for developing unusual antibiotics. In this study, clavanin A, an antimicrobial peptide previously isolated from the marine tunicateStyela clava, was selected as a purposeful molecule that could be used in controlling infection and further synthesized. Clavanin A wasin vitroevaluated againstStaphylococcus aureusandEscherichia colias well as toward L929 mouse fibroblasts and skin primary cells (SPCs). Moreover, this peptide was challenged here in anin vivowound and sepsis model, and the immune response was also analyzed. Despite displaying clearin vitroantimicrobial activity toward Gram-positive and -negative bacteria, clavanin A showed no cytotoxic activities against mammalian cells, and in acute toxicity tests, no adverse reaction was observed at any of the concentrations. Moreover, clavanin A significantly reduced theS. aureusCFU in an experimental wound model. This peptide also reduced the mortality of mice infected withE. coliandS. aureusby 80% compared with that of control animals (treated with phosphate-buffered saline [PBS]): these data suggest that clavanin A prevents the start of sepsis and thereby reduces mortality. These data suggest that clavanin A is an AMP that could improve the development of novel peptide-based strategies for the treatment of wound and sepsis infections.

scholarly journals Green Strategy–Based Synthesis of Silver Nanoparticles for Antibacterial Applications

2021 ◽  
Vol 3 ◽  
Author(s):  
Kenneth Ssekatawa ◽  
Denis K. Byarugaba ◽  
Charles D. Kato ◽  
Eddie M. Wampande ◽  
Francis Ejobi ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Bacterial Infections ◽  
Maximum Growth ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Microscopy Imaging ◽  
Prunus Africana ◽  
Vis Spectroscopy ◽  
Biosynthesized Agnps ◽  
Average Size

Antibiotics have been the nucleus of chemotherapy since their discovery and introduction into the healthcare system in the 1940s. They are routinely used to treat bacterial infections and to prevent infections in patients with compromised immune systems and enhancing growth in livestock. However, resistance to last-resort antibiotics used in the treatment of multidrug-resistant infections has been reported worldwide. Therefore, this study aimed to evaluate green synthesized nanomaterials such as silver nanoparticles (AgNPs) as alternatives to antibiotics. UV-vis spectroscopy surface plasmon resonance peaks for AgNPs were obtained between 417 and 475 nm. An X-ray diffraction analysis generated four peaks for both Prunus africana extract (PAE) and Camellia sinensis extract (CSE) biosynthesized AgNPs positioned at 2θ angles of 38.2°, 44.4°, 64.5°, and 77.4° corresponding to crystal planes (111), (200), (220), and (311), respectively. A dynamic light-scattering analysis registered the mean zeta potential of +6.3 mV and +0.9 mV for PAE and CSE biosynthesized nanoparticles, respectively. Fourier transform infrared spectroscopy spectra exhibited bands corresponding to different organic functional groups confirming the capping of AgNPs by PAE and CSE phytochemicals. Field emission scanning electron microscopy imaging showed that AgNPs were spherical with average size distribution ranging from 10 to 19 nm. Biosynthesized AgNPs exhibited maximum growth inhibitory zones of 21 mm with minimum inhibitory concentration and minimum bactericidal concentration of 125 and 250 μg/ml, respectively, against carbapenem-resistant bacteria.

scholarly journals Deimmunized Lysostaphin Synergizes with Small-molecule Chemotherapies and Re-sensitizes MRSA to β-Lactam Antibiotics

2020 ◽  
pp. AAC.01707-20
Author(s):  
Yongliang Fang ◽  
Jack R. Kirsch ◽  
Liang Li ◽  
Seth A. Brooks ◽  
Spencer Heim ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Standard Of Care ◽  
Rapid Onset ◽  
Multidrug Resistant ◽  
Genetically Engineered ◽  
High Potency ◽  
Onset Of Action ◽  
New Antibiotics

There is an urgent need for novel agents to treat drug-resistant bacterial infections, such as multidrug-resistant Staphylococcus aureus (MRSA). Desirable properties for new antibiotics include high potency, narrow species selectivity, low propensity to elicit new resistance phenotypes, and synergy with standard of care (SOC) chemotherapies. Here, we describe analysis of the anti-MRSA potential exhibited by F12, an innovative anti-MRSA lysin that has been genetically engineered to evade detrimental antidrug immune responses in human patients. F12 possesses high potency and rapid onset of action, it has narrow selectivity against pathogenic Staphylococci, and it manifests synergy with numerous SOC antibiotics. Additionally, resistance to F12 and β-lactam antibiotics appears mutually exclusive, and importantly we provide evidence that F12 re-sensitizes normally resistant MRSA strains to β-lactams both in vitro and in vivo. These results suggest that combinations of F12 and SOC antibiotics could be a promising new approach to treating refractory S. aureus infections.

scholarly journals In vitro and in vivo antibacterial efficacies of CFC-222, a new fluoroquinolone.

1997 ◽  
Vol 41 (10) ◽  
pp. 2209-2213 ◽  
Author(s):  
J H Kim ◽  
J A Kang ◽  
Y G Kim ◽  
J W Kim ◽  
J H Lee ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Protective Efficacy ◽  
Horse Serum ◽  
The Other ◽  
Infection Model ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli

CFC-222 is a novel fluoroquinolone containing a C-7 bicyclic amine moiety with potent antibacterial activities against gram-positive, gram-negative, and anaerobic organisms. We compared the in vitro and in vivo activities of CFC-222 with those of ciprofloxacin, ofloxacin, and lomefloxacin. CFC-222 was more active than the other fluoroquinolones tested against gram-positive bacteria. CFC-222 was particularly active against Streptococcus pneumoniae (MIC at which 90% of isolates are inhibited [MIC90], 0.2 microg/ml), Staphylococcus aureus (MIC90, 0.2 microg/ml for ciprofloxacin-susceptible strains), and Enterococcus faecalis (MIC90, 0.39 microg/ml). Against Escherichia coli and other members of the family Enterobacteriaceae, CFC-222 was slightly less active than ciprofloxacin (MIC90s for E. coli, 0.1 and 0.025 microg/ml, respectively). The in vitro activity of CFC-222 was not influenced by inoculum size, medium composition, or the presence of horse serum. However, its activity was decreased significantly by a change in the pH of the medium from 7.0 to 6.0, as was the case for the other quinolones tested. The in vivo protective efficacy of CFC-222 by oral administration was greater than those of the other quinolones tested in a mouse model of intraperitoneally inoculated systemic infection caused by S. aureus. CFC-222 exhibited efficacy comparable to that of ciprofloxacin in the same model of infection caused by gram-negative organisms, such as E. coli and Klebsiella pneumoniae. In this infection model, CFC-222 was slightly less active than ciprofloxacin against Pseudomonas aeruginosa. These results suggest that CFC-222 may be a promising therapeutic agent in various bacterial infections.

scholarly journals Microwave-Assisted Synthesis of Chitosan/Polyvinyl Alcohol Silver Nanoparticles Gel for Wound Dressing Applications

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Nguyen Thi Hiep ◽  
Huynh Chan Khon ◽  
Vo Van Thanh Niem ◽  
Vo Van Toi ◽  
Tran Ngoc Quyen ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Microwave Irradiation ◽  
Polyvinyl Alcohol ◽  
Silver Ions ◽  
Diffusion Method ◽  
Poly Vinyl Alcohol ◽  
Microwave Assisted Synthesis ◽  
Vis Spectroscopy

The purpose of this study was to fabricate chitosan/poly(vinyl alcohol)/Ag nanoparticles (CPA) gels with microwave-assistance for skin applications. Microwave irradiation was employed to reduce silver ions to silver nanoparticles and to crosslink chitosan (CS) with polyvinyl alcohol (PVA). The presence of silver nanoparticles in CPA gels matrix was examined using UV-Vis spectroscopy, transmission electron microscopy, and X-ray diffraction. The interaction of CS and PVA was analysed by Fourier transform infrared spectroscopy. The release of silver ions was determined by atomic absorption spectrometry. The antimicrobial properties of CPA gels againstP. aeruginosaandS. aureuswere investigated using agar diffusion method. Finally, the biocompatibility and wound-healing ability of the gels were studied using fibroblast cells (in vitro) and mice models (in vivo). In conclusion, the results showed that CPA gels were successfully fabricated using microwave irradiation method. These gels can be applied to heal an open wound thanks to their antibacterial activity and biocompatibility.

An effective zinc phthalocyanine derivative against multidrug-resistant bacterial infection

2017 ◽  
Vol 21 (03) ◽  
pp. 205-210 ◽  
Author(s):  
Dong Wang ◽  
Yuxiang Zhang ◽  
Shufeng Yan ◽  
Zihan Chen ◽  
Yicai Deng ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Red Light ◽  
Multidrug Resistant ◽  
Zinc Phthalocyanine ◽  
In Vivo Studies ◽  
Infection Model ◽  
Clinical Test ◽  
Phthalocyanine Derivative

Bacterial skin and soft tissue infections are abundant worldwide. The rise in the incidence of multidrug-resistant (MDR) bacterial infections has made the need for alternative means of treatment more pressing. We herein report a zinc phthalocyanine derivative, pentalysine [Formula: see text]-carbonylphthalocyanine zinc (ZnPc-(Lys)[Formula: see text] and its strong capability of killing nosocomial MDR bacteria, including MDR-Escherichia coli and MDR-Acinetobacter baumannii. In vitro studies, we observed that ZnPc-(Lys)5 in micromolar concentrations killed above MDR bacteria in 6~6.5 log10 orders with only 5-min illumination of red light at a dosage of 12.75 J/cm[Formula: see text]. Further in vivo studies on a mouse infection model demonstrated that ZnPc-(Lys)5 efficiently inhibited the MDR bacterial growth after one-time photodynamic antibacterial therapy and, interestingly, significantly accelerated the wound healing. Putting together, our findings establish ZnPc-(Lys)5 as a potent antimicrobial candidate for the clinical test on localized infection.

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