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Published on: April 21, 2023
Inhibition of the Vancomycin Resistance in Staphylococcus aureus in Egypt Using Silver Nanoparticles
Nouran M Salah1,2, Amal E Saafan2, Eman H Salem3
1Genetic Engineering and Biotechnology Research Institute, University of Sadat City, Egypt.
Abstract:
Staphylococcus aureus is a major human pathogen that is sometimes resistant to vancomycin. In this study, the prevalence of vancomycin-resistant Staphylococcus aureus (VRSA) was studied. 100 isolates of S. aureus were identified based on biochemical and molecular evidence. The antibiotic susceptibility of the studied isolates was tested against 13 antibiotics by the disc diffusion method that showed 24 vancomycin-resistant isolates. The minimum inhibitory concentrations (MICs) were estimated by the agar dilution method to determine vancomycin intermediate-resistant S. aureus (VISA) and VRSA. The resistance gene cluster (vanA, vanR, vanH, and vanY) was amplified by PCR and then sequenced. Amplification of vanA and vanR genes showed that they are present in 21.4% and 14.3% of VRSA isolates, respectively, whereas none of the studied genes has been detected in VISA strains. A significant antimicrobial effect toward VRSA isolates using silver nanoparticles (AgNPs) synthesized from S. aureus and rosemary leaves was recorded. This study confirmed the existence of VRSA strains in Egypt. Furthermore, the use of silver nanoparticles inhibits these vancomycin-resistant S. aureus strains in vitro.
Insights
Vancomycin-resistant Staphylococcus aureus (VRSA) strains were identified in Egypt. Silver nanoparticles (AgNPs) showed significant in vitro antimicrobial activity against these resistant bacteria, offering a potential new treatment strategy.
Area of Science:
- Microbiology
- Infectious Diseases
- Nanotechnology
Background:
- Staphylococcus aureus is a significant human pathogen.
- Emergence of vancomycin resistance in S. aureus poses a major public health threat.
- Understanding the prevalence and genetic basis of vancomycin resistance is crucial.
Purpose of the Study:
- To investigate the prevalence of vancomycin-resistant Staphylococcus aureus (VRSA) in Egypt.
- To characterize the genetic determinants of vancomycin resistance in S. aureus isolates.
- To evaluate the efficacy of silver nanoparticles (AgNPs) as a potential antimicrobial agent against VRSA.
Main Methods:
- Identification of 100 S. aureus isolates using biochemical and molecular methods.
- Antibiotic susceptibility testing via disc diffusion and MIC determination (agar dilution).
- Detection of vancomycin resistance genes (vanA, vanR, vanH, vanY) using PCR and sequencing.
- Synthesis and in vitro antimicrobial evaluation of silver nanoparticles (AgNPs).
Main Results:
- 24 out of 100 S. aureus isolates exhibited vancomycin resistance.
- vanA and vanR genes were detected in 21.4% and 14.3% of VRSA isolates, respectively.
- No vancomycin resistance genes were found in vancomycin intermediate-resistant S. aureus (VISA) strains.
- Synthesized AgNPs demonstrated significant in vitro antimicrobial activity against VRSA isolates.
Conclusions:
- This study confirms the presence of VRSA strains in Egypt.
- The vanA and vanR genes are associated with VRSA in this cohort.
- Silver nanoparticles show promise as an effective in vitro treatment against vancomycin-resistant S. aureus.
