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Multiplex PCR Assay for Typing of Staphylococcal Cassette Chromosome Mec Types I to V in Methicillin-resistant Staphylococcus aureus
Published on: September 5, 2013
CRISPR-Cas9-Mediated Targeting of Multidrug Resistance Genes in Methicillin-Resistant Staphylococcus aureus
Aysegul Ates1, Cihan Tastan2,3, Safak Ermertcan1
1Pharmeceutical Microbiology Department, Faculty of Pharmacy, Ege University, Izmir, Turkey.
Abstract:
Antibiotic resistance poses a global health crisis limiting the efficacy of available therapeutic agents. We explored CRISPR-Cas-based antimicrobials to combat multidrug resistance in methicillin-resistant Staphylococcus aureus (MRSA), targeting methicillin (mecA), gentamicin (aacA), and ciprofloxacin (grlA, grlB) resistance genes. Engineered CRISPR plasmids with specific single-guide RNAs were electroporated into MRSA strains. Real-time polymerase chain reaction assessed gene expression changes, while antibiotic susceptibility tests (ASTs) evaluated resistance status. Results showed a 1.5-fold decrease in mecA, a 5.5-fold decrease in grlA, a 6-fold decrease in grlB, and a 4-fold decrease in aacA expression. ASTs demonstrated the reversal of resistance to beta-lactam, quinolone, and aminoglycoside antibiotics. Western blot analysis revealed a 70% decrease in penicillin-binding protein 2a expression. Sanger sequencing confirmed point mutations in the grlB and aacA genes. Our findings highlight the potential of CRISPR-Cas9 technology to restore antibiotic efficacy against multidrug-resistant pathogens.
Insights
CRISPR-Cas technology effectively combats antibiotic resistance in MRSA by targeting key resistance genes. This approach restores the efficacy of essential antibiotics against multidrug-resistant bacteria.
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Background:
- Antibiotic resistance is a critical global health threat.
- Methicillin-resistant Staphylococcus aureus (MRSA) is a major multidrug-resistant pathogen.
- CRISPR-Cas systems offer a novel antimicrobial strategy.
Purpose of the Study:
- To investigate the efficacy of CRISPR-Cas-based antimicrobials against MRSA.
- To target specific antibiotic resistance genes: methicillin (mecA), gentamicin (aacA), and ciprofloxacin (grlA, grlB).
Main Methods:
- Engineered CRISPR plasmids with single-guide RNAs were introduced into MRSA.
- Real-time PCR measured gene expression changes.
- Antibiotic susceptibility tests (ASTs) assessed resistance.
- Western blot and Sanger sequencing were used for validation.
Main Results:
- Significant reductions in mecA, aacA, grlA, and grlB gene expression were observed.
- CRISPR-Cas treatment reversed resistance to beta-lactam, quinolone, and aminoglycoside antibiotics.
- Penicillin-binding protein 2a expression decreased by 70%.
Conclusions:
- CRISPR-Cas9 technology shows significant potential for restoring antibiotic efficacy against MRSA.
- This approach offers a promising strategy to combat multidrug resistance in bacterial pathogens.
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