Related Experiment Video
Updated: Aug 8, 2026

14:04
Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria
Published on: May 8, 2013
Gentamicin resistance in Staphylococcus aureus--a new mechanism?
The Journal of Antimicrobial Chemotherapy
|March 1, 1983
Summary
Researchers cured multiply-resistant Staphylococcus aureus of gentamicin resistance. Some strains showed reduced antibiotic modification and increased uptake, while others revealed novel resistance mechanisms beyond enzyme alteration.
Area of Science:
- Microbiology
- Molecular Biology
- Antimicrobial Resistance
Background:
- Staphylococcus aureus is a significant human pathogen.
- Multiply-resistant strains pose a major public health threat.
- Gentamicin resistance in S. aureus is often mediated by aminoglycoside-modifying enzymes.
Purpose of the Study:
- To investigate the mechanisms of gentamicin resistance loss in multiply-resistant Staphylococcus aureus.
- To determine the relationship between aminoglycoside-modifying enzymes and gentamicin uptake.
- To identify potential novel resistance mechanisms in S. aureus.
Main Methods:
- Curing multiply-resistant Staphylococcus aureus strains of gentamicin resistance.
- Measuring intracellular gentamicin accumulation in resistant and sensitive variants.
- Assessing the production of aminoglycoside-modifying enzymes in different strains.
Main Results:
- Three strains showed reduced gentamicin resistance linked to decreased aminoglycoside-modifying enzymes and increased intracellular gentamicin accumulation.
- Three strains exhibited gentamicin resistance loss without a direct correlation to altered enzyme activity or uptake.
- Two strains retained aminoglycoside-modifying enzymes and showed no increased gentamicin accumulation, suggesting unknown resistance mechanisms.
Conclusions:
- Aminoglycoside modification is a key mechanism for gentamicin resistance in some S. aureus strains, impacting antibiotic uptake.
- Novel, undescribed mechanisms contribute to broad-spectrum aminoglycoside resistance in certain S. aureus isolates.
- Further research is needed to elucidate these alternative resistance pathways.
Related Concept Videos
Gene Regulation in Microbial Communities: Quorum Sensing
Quorum sensing is a mechanism of bacterial communication that enables coordinated gene expression in response to changes in population density. This facilitates collective behaviors that enhance survival, resource acquisition, and ecological adaptation. This process relies on small signaling molecules called autoinducers that accumulate as bacterial populations grow. When a critical threshold concentration of autoinducers is reached, bacterial cells collectively modify gene expression,...
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...
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 Gram-positive Cell Wall Synthesis
Bacterial cell walls are typically rigid structures composed mainly of peptidoglycan, a mesh-like polymer that provides mechanical strength and maintains cell shape. The synthesis of peptidoglycan is a crucial process in bacterial growth and serves as a primary target for many antibiotics.Mechanism of Action of Beta-Lactam AntibioticsBeta-lactam antibiotics, such as penicillin, inhibit peptidoglycan synthesis in actively growing cells. These antibiotics share a characteristic four-membered...
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 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...

