scholarly journals Antimicrobial and Biocompatible Polycaprolactone and Copper Oxide Nanoparticle Wound Dressings against Methicillin-Resistant Staphylococcus aureus

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1692
Author(s):  
Jennifer Balcucho ◽  
Diana M. Narváez ◽  
Jinneth Lorena Castro-Mayorga
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Copper Oxide ◽  
Metallic Nanoparticles ◽  
Antimicrobial Agents ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Inhibitory Effect ◽  
Wound Dressings ◽  
Scanning Calorimetry ◽  
Methicillin Resistant

One of the major health problems linked to methicillin-resistant Staphylococcus aureus (MRSA) is severe diabetic foot ulcers (DFU), which are associated with hospital-acquired infections, lower limb amputations and emerging resistance to the current antibiotics. As an alternative, this work aims to develop a biodegradable and biocompatible material with antimicrobial capacity to prevent DFU. This was achieved by producing active polymeric films with metallic nanoparticles dispersed through a polycaprolactone (PCL) dressing. First, the antimicrobial activity of copper oxide nanoparticles (CuONPs) was tested by the microdilution method, selecting the lowest concentration that has an inhibitory effect on MRSA. Then, active PCL films were prepared and characterized in terms of their physicochemical properties, antimicrobial performance, cytotoxicity, genotoxicity and hemocompatibility. Active films had chemical and thermal properties like the ones without the antimicrobial agents, which was confirmed through FTIR, Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) analysis. In relation to antimicrobial activity, active PCL films inhibited MRSA growth when treated with CuONPs at a concentration of 0.07% (w/w). After exposure to the active film extracts, human foreskin fibroblast cells (ATCC® SCRC1041™) (HFF-1) exhibited a cell viability average above 80% for all treatments and no DNA damage was found. Finally, PCL films with 0.07% (w/w) CuONPs proved to be hemocompatible, and none of the films evaluated had red blood cell breakage greater than 5%, being within the acceptable limits established by the International Organization for Standardization ISO 10993-4:2002.

scholarly journals Antibacterial Activity of Saponin Extracted from Phyllanthus niruri on Methicillin-Resistant Staphylococcus aureus (MRSA)

2019 ◽  
pp. 1-9
Author(s):  
V. A. Ajibade ◽  
V. O. Oluwasusi ◽  
M. F. Ibiyemi ◽  
O. A. Ajenifuja ◽  
O. Famurewa
Keyword(s):  
Staphylococcus Aureus ◽  
Nuclear Magnetic Resonance ◽  
Antimicrobial Activity ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Inhibitory Effect ◽  
Diffusion Method ◽  
Phyllanthus Niruri ◽  
Methicillin Resistant ◽  
Agar Diffusion Method ◽  
Conventional Antibiotics

The antimicrobial activity of saponin extracted from Phyllanthus niruri was investigated on methicillin-resistant Staphylococcus aureus (MRSA). The nuclear magnetic resonance (NMR) was used to determine the structure spectra of the extracted purified saponin. The 13carbon NMR predicted on the basis of chemical shift that appeared in the resonances of 20 – 60 ppm gave a structure named Phylagenin-13-O-α-D-glucopyranoside and Phylagenin-25-O-β-D-glucopyra-noside. The susceptibility profile of MRSA determined by the agar-diffusion method showed that 97.0% and 90.0% of the test bacterium were resistant to Tetracycline and Cotrimoxazole respectively and 60% of the bacterium was susceptible to saponin extract. The ability of saponin extracted from P. niruri to treat clinical manifestation like chest congestion and skin desquamation from which S. aureus resistant to conventional antibiotics have been isolated has been confirmed in this study. The fact that this extract exerted an inhibitory effect on MRSA indicates that they can potentially be further developed into antimicrobial clinically used agents.

scholarly journals Screening of Actinomycetes from Soil for Antibacterial Activity

2020 ◽  
Vol 8 (3) ◽  
pp. 102-110
Author(s):  
Shailesh Budhathoki ◽  
Anima Shrestha
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Antimicrobial Agents ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Test Organism ◽  
Inhibitory Effect ◽  
Soil Samples ◽  
Aureus Strain ◽  
Methicillin Resistant ◽  
Test Organisms

Actinomycetes are Gram positive, free living saprophytes which are distributed in soil as one of the major populations and are primary source of antibiotics. This study was carried out with a quest to isolate actinomycetes from soil samples of different places and assess their antibacterial activity. Isolation of actinomycetes was carried out by serial dilution of soil sample followed by spread plate method. The antimicrobial extract was extracted using ethyl acetate. Assessment of antimicrobial activity was performed by using Agar cup plate assay against test organisms (Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Salmonella typhi, Salmonella paratyphi, Bacillus subtilis, Staphylococcus aureus). Antibacterial activity was tested against Methicillin Sensitive Staphylococcus aureus and Methicillin Resistant Staphylococcus aureus in the isolates having effective inhibitory activity against Staphylococcus aureus. From 15 soil samples of 12 different locations, 121 actinomycetes isolates were isolated. Among them, 58 (47.9%) isolates were inhibitory against at least 1 test organism in primary screening, of which 22 isolates effective against more than 1 test organism was chosen for secondary screening. Out of them, 8 were inhibitory against 2 test organisms while 14 were inhibitory against 3 test organisms. Staphylococcus aureus was found to be the most susceptible test organism with its susceptibility against 12 actinomycetes isolates. Among 12 isolates effective against Staphylococcus aureus, 10 were found to have an inhibitory effect against Methicillin Susceptible Staphylococcus aureus while 6 were found to have inhibitory effect against Methicillin Resistant Staphylococcus aureus strain. The findings of this study highlight the inhibitory potential of actinomycetes and the need for further investigation for obtaining novel antimicrobial agents from actinomycetes from various unexplored areas.

scholarly journals Antimicrobial Metabolites against Methicillin-Resistant Staphylococcus aureus from the Endophytic Fungus Neofusicoccum australe

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1094
Author(s):  
Melissa M. Cadelis ◽  
Soeren Geese ◽  
Benedict B. Uy ◽  
Daniel R. Mulholland ◽  
Shara J. van de Pas ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Natural Products ◽  
Structure Elucidation ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Inhibitory Concentration ◽  
Spectroscopic Methods ◽  
Methicillin Resistant ◽  
Bioassay Guided Fractionation ◽  
Antimicrobial Metabolites

Antimicrobial bioassay-guided fractionation of the endophytic fungi Neofusicoccum australe led to the isolation of a new unsymmetrical naphthoquinone dimer, neofusnaphthoquinone B (1), along with four known natural products (2–5). Structure elucidation was conducted by nuclear magnetic resonance (NMR) spectroscopic methods, and the antimicrobial activity of all the natural products was investigated, revealing 1 to be moderately active towards methicillin-resistant Staphylococcus aureus (MRSA) with a minimum inhibitory concentration (MIC) of 16 µg/mL.

scholarly journals Methicillin-resistant Staphylococcus aureus bloodstream infection: risk factors and clinical outcome in non-intensive-care units

2012 ◽  
Vol 45 (2) ◽  
pp. 189-193 ◽  
Author(s):  
Karinne Spirandelli Carvalho Naves ◽  
Natália Vaz da Trindade ◽  
Paulo Pinto Gontijo Filho
Keyword(s):  
Risk Factors ◽  
Staphylococcus Aureus ◽  
Bloodstream Infection ◽  
Antimicrobial Agents ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Methicillin Resistance ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Methicillin Resistant ◽  
Staphylococcus Aureus Bloodstream Infection

INTRODUCTION: Methicillin-resistant Staphylococcus aureus (MRSA) is spread out in hospitals across different regions of the world and is regarded as the major agent of nosocomial infections, causing infections such as skin and soft tissue pneumonia and sepsis. The aim of this study was to identify risk factors for methicillin-resistance in Staphylococcus aureus bloodstream infection (BSI) and the predictive factors for death. METHODS: A retrospective cohort of fifty-one patients presenting bacteraemia due to S. aureus between September 2006 and September 2008 was analysed. Staphylococcu aureus samples were obtained from blood cultures performed by clinical hospital microbiology laboratory from the Uberlândia Federal University. Methicillinresistance was determined by growth on oxacillin screen agar and antimicrobial susceptibility by means of the disk diffusion method. RESULTS: We found similar numbers of MRSA (56.8%) and methicillin-susceptible Staphylococcus aureus (MSSA) (43.2%) infections, and the overall hospital mortality ratio was 47%, predominantly in MRSA group (70.8% vs. 29.2%) (p=0.05). Age (p=0.02) was significantly higher in MRSA patients as also was the use of central venous catheter (p=0.02). The use of two or more antimicrobial agents (p=0.03) and the length of hospital stay prior to bacteraemia superior to seven days (p=0.006) were associated with mortality. High odds ratio value was observed in cardiopathy as comorbidity. CONCLUSIONS: Despite several risk factors associated with MRSA and MSSA infection, the use of two or more antimicrobial agents was the unique independent variable associated with mortality.

scholarly journals The Frequency of Methicillin-Resistant Staphylococcus aureus and Coagulase Gene Polymorphism in Egypt

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Hend M. Abdulghany ◽  
Rasha M. Khairy
Keyword(s):  
Staphylococcus Aureus ◽  
Gene Polymorphism ◽  
Antimicrobial Susceptibility ◽  
Antimicrobial Agents ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Susceptibility Testing ◽  
Antimicrobial Susceptibility Testing ◽  
Methicillin Resistant ◽  
Microbiological Methods ◽  
Rflp Typing

The current study aimed to use Coagulase gene polymorphism to identify methicillin-resistant Staphylococcus aureus (MRSA) subtypes isolated from nasal carriers in Minia governorate, Egypt, evaluate the efficiency of these methods in discriminating variable strains, and compare these subtypes with antibiotypes. A total of 400 specimens were collected from nasal carriers in Minia governorate, Egypt, between March 2012 and April 2013. Fifty-eight strains (14.5%) were isolated and identified by standard microbiological methods as MRSA. The identified isolates were tested by Coagulase gene RFLP typing. Out of 58 MRSA isolates 15 coa types were classified, and the amplification products showed multiple bands (1, 2, 3, 4, 5, and 8 bands). Coagulase gene PCR-RFLPs exhibited 10 patterns that ranged from 1 to 8 fragments with AluI digestion. Antimicrobial susceptibility testing with a panel of 8 antimicrobial agents showed 6 different antibiotypes. Antibiotype 1 was the most common phenotype with 82.7%. The results have demonstrated that many new variants of the coa gene are present in Minia, Egypt, different from those reported in the previous studies. So surveillance of MRSA should be continued.

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