Related Experiment Video

Updated: Aug 17, 2026

Subcutaneous Infection of Methicillin Resistant Staphylococcus Aureus (MRSA)
12:18

Subcutaneous Infection of Methicillin Resistant Staphylococcus Aureus (MRSA)

Published on: February 9, 2011

Biochemical basis of mupirocin resistance in strains of Staphylococcus aureus

T H Farmer1, J Gilbart, S W Elson

  • 1SmithKline Beecham Pharmaceuticals, Betchworth, Surrey, UK.

The Journal of Antimicrobial Chemotherapy
|November 1, 1992
PubMed

Insights

Mupirocin resistance in Staphylococcus aureus is primarily caused by modifications to the target enzyme, isoleucyl-tRNA synthetase (IRS). This study found a strong correlation between enzyme inhibition and antibiotic resistance levels in various bacterial strains.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Biochemistry

Background:

  • Mupirocin is a crucial antibiotic for treating Staphylococcus aureus infections.
  • Understanding antibiotic resistance mechanisms is vital for effective treatment strategies.

Purpose of the Study:

  • To investigate the mechanism of mupirocin resistance in Staphylococcus aureus.
  • To determine the correlation between mupirocin's effect on isoleucyl-tRNA synthetase (IRS) and bacterial resistance levels.

Main Methods:

  • Examined 21 Staphylococcus aureus strains with varying mupirocin resistance.
  • Assessed the time-dependent inhibition of isoleucyl-tRNA synthetase (IRS) by mupirocin.
  • Correlated minimum inhibitory concentrations (MICs) with IRS inhibition (I50) values.

Main Results:

  • Mupirocin demonstrated time-dependent inhibition of IRS, with greater inhibition in sensitive strains.
  • IRS I50 values strongly correlated with mupirocin MICs across sensitive, moderately resistant, and highly resistant strains.
  • No mupirocin degradation was observed in resistant S. aureus cell-free extracts.

Conclusions:

  • Modified isoleucyl-tRNA synthetase (IRS) enzyme is the primary mechanism conferring mupirocin resistance in the studied Staphylococcus aureus strains.
  • The study highlights the importance of IRS enzyme modification in bacterial antibiotic resistance.

More Related Videos

Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria14:04

Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria

Published on: May 8, 2013

Time-Lapse Epifluorescence Microscopy Imaging of Pseudomonas aeruginosa and Staphylococcus aureus Heterogeneous Phenotypes07:44

Time-Lapse Epifluorescence Microscopy Imaging of Pseudomonas aeruginosa and Staphylococcus aureus Heterogeneous Phenotypes

Published on: February 14, 2025

Related Concept Videos

Mismatch Repair01:36

Mismatch Repair

Overview
Development of Antibiotic Resistance01:30

Development of Antibiotic Resistance

Antibiotic resistance is a major public health concern that arises when bacteria evolve mechanisms to withstand the effects of antibiotic treatments. This resistance can be intrinsic, acquired through genetic mutations, or transferred between bacteria via horizontal gene transfer. The development of antibiotic resistance poses significant challenges in treating bacterial infections and necessitates ongoing research to develop new therapeutic strategies.Intrinsic resistance occurs when bacterial...
Staphylococcal Skin Infections01:29

Staphylococcal Skin Infections

Staphylococcus aureus is a Gram-positive coccus that resides harmlessly on the skin and mucous membranes of healthy individuals. When the skin barrier is breached, it can shift from a commensal to an opportunistic pathogen. This transition is facilitated by surface adhesins, such as clumping factor B and S. aureus surface protein G (SasG), which bind to structural proteins, including loricrin and cytokeratin, in the damaged epidermis. Protein A, another key factor, binds the Fc region of...
Mechanism of Antibiotic Resistance in MRSA01:25

Mechanism of Antibiotic Resistance in MRSA

Antibiotic resistance in bacteria arises when microorganisms evolve the ability to withstand drugs designed to kill them or inhibit their growth, rendering once-effective treatments useless. This phenomenon, driven by genetic change and selection under antibiotic exposure, poses a profound threat to modern medicine. Mechanisms include drug-inactivating enzymes (e.g., β-lactamases), efflux pumps that eject antibiotics, mutations altering antibiotic targets, decreased drug uptake, and acquisition...
Inhibitors of Bacterial Protein Synthesis01:25

Inhibitors of Bacterial Protein Synthesis

Aminoglycosides constitute a highly potent class of bactericidal antibiotics that exert their antimicrobial effects by targeting the bacterial ribosome, specifically disrupting protein synthesis. These polycationic molecules consist of amino-modified sugars linked via glycosidic bonds to an aminocyclitol core such as 2-deoxystreptamine or streptamine. Their strong positive charges facilitate tight binding to the negatively charged phosphate backbone of ribosomal RNA (rRNA), primarily at the 16S...
Clinical Significance of Antibiotic Resistance01:25

Clinical Significance of Antibiotic Resistance

Methicillin-resistant Staphylococcus aureus (MRSA) presents a critical public health threat, arising from its capacity to resist β-lactam antibiotics due to acquisition of the mecA gene within the staphylococcal cassette chromosome mec (SCCmec). This gene encodes penicillin-binding protein 2a (PBP2a), which impairs binding efficacy of methicillin and other β-lactams. MRSA has evolved into distinct clonal lineages impacting humans and animals alike, reinforcing its significance within the One...