Related Experiment Video
Updated: Aug 6, 2026
Evaluation of Antimicrobial Activities of Nanoparticles and Nanostructured Surfaces In Vitro
Published on: April 21, 2023
Antimicrobial and barrier effects of silver against methicillin-resistant Staphylococcus aureus
1Research Development Unit, St Augustine's, Manchester Metropolitan University, Manchester, UK. v.e.jones@mmu.ac.uk
Objective:
Two strains of methicillin-resistant Staphylococcus aureus (MRSA), termed epidemic strains (EMRSA-15 and EMRSA-16), were used to evaluate the antimicrobial and barrier effect of four silver dressings (two silver donating and two non-silver-donating) available in the UK at the time of the study.
Method:
The moist surface of a blood agar plate was covered with 10(6) colony-forming units of the respective strain of MRSA, and dressings were applied to the surface and incubated at 37 degrees C for different time periods and the upper and lower surfaces subcultured for residual growth.
Results:
The nanocrystalline dressings (silver donating) were effective as a barrier from one hour until the study end (72 hours): no penetration of EMRSA-15 and EMRSA-16 through the dressing occurred. Moreover, the nanocrystalline dressings showed some antimicrobial activity at one hour in the areas underneath and surrounding the dressing until the study end. The remaining two dressings had no barrier effect and only demonstrated limited antimicrobial activity after 24 hours.
Conclusion:
This in vitro study suggests that the nanocrystalline dressings are more effective than other silver dressings in terms of providing a barrier function and antimicrobial activity against EMRSA-15 and EMRSA-16.
Insights
Nanocrystalline silver dressings provided superior barrier and antimicrobial effects against epidemic methicillin-resistant Staphylococcus aureus (MRSA) strains EMRSA-15 and EMRSA-16 in vitro. Other silver dressings showed limited efficacy.
Area of Science:
- Microbiology
- Infectious Diseases
- Wound Care
Background:
- Methicillin-resistant Staphylococcus aureus (MRSA) poses a significant healthcare challenge.
- Epidemic strains like EMRSA-15 and EMRSA-16 are of particular concern.
- Effective wound management strategies are crucial for controlling MRSA infections.
Purpose of the Study:
- To evaluate the antimicrobial and barrier properties of silver dressings against MRSA.
- To compare silver-donating and non-silver-donating dressings.
- To assess the efficacy of nanocrystalline silver dressings.
Main Methods:
- In vitro study using two MRSA strains (EMRSA-15 and EMRSA-16).
- Application of four different silver dressings to inoculated blood agar plates.
- Incubation at 37°C with assessment of barrier and antimicrobial activity over time.
Main Results:
- Nanocrystalline silver dressings demonstrated complete barrier function against MRSA penetration from 1 to 72 hours.
- These dressings also exhibited antimicrobial activity in surrounding areas.
- Non-silver-donating dressings lacked barrier effect and showed only limited antimicrobial activity after 24 hours.
Conclusions:
- Nanocrystalline silver dressings offer superior barrier and antimicrobial efficacy against EMRSA-15 and EMRSA-16 compared to other tested silver dressings.
- This suggests potential benefits for wound care in managing MRSA infections.
- Further in vivo studies may be warranted to confirm these findings.
Related Concept Videos
01:25Clinical Significance of Antibiotic Resistance
01:25Mechanism of Antibiotic Resistance in MRSA
01:18Surface Membrane Barriers
The outer layer of the skin, the epidermis, is a robust barrier comprising layers of closely packed keratinized cells. This dense arrangement prevents microbes from penetrating the body. The periodic shedding of epidermal cells...
01:28Antimicrobial Effectiveness
01:29Staphylococcal Skin Infections
01:23Antimicrobial Proteins
Interferons
Interferons (IFNs) are proteins produced by lymphocytes, macrophages, and fibroblasts infected with viruses. While IFNs cannot prevent viruses from entering and...