Related Experiment Video

Updated: Apr 15, 2026

Development and Assessment of Intracellular Infection Models for Staphylococcus aureus
08:32

Development and Assessment of Intracellular Infection Models for Staphylococcus aureus

Published on: January 17, 2025

1.5K

Impact of daptomycin resistance on Staphylococcus aureus virulence

David R Cameron1, Lawrence I Mortin, Aileen Rubio

  • 1a Department of Microbiology ; School of Biomedical Sciences; Monash University ; Melbourne , Australia.

Virulence
|April 2, 2015
PubMed

Insights

Mutations causing daptomycin resistance (DAP(R)) in Staphylococcus aureus also reduce its virulence. This study investigated the link between DAP(R) genetic changes and pathogenicity in infection models.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Genetics

Background:

  • Daptomycin resistance (DAP(R)) in Staphylococcus aureus is a growing clinical concern.
  • Mutations conferring DAP(R) are often found in genes linked to bacterial pathogenesis.

Purpose of the Study:

  • To investigate the relationship between genetic mutations causing DAP(R) and Staphylococcus aureus virulence.
  • To determine if DAP(R) mutations impact pathogenicity in vivo.

Main Methods:

  • Laboratory-evolved DAP-resistant Staphylococcus aureus strains were generated.
  • Virulence was assessed using Galleria mellonella and murine infection models.
  • Genetic mutations (walK, rpoC, mprF) and their effect on DAP minimum inhibitory concentration (MIC) and virulence were analyzed.

Main Results:

  • Increasing DAP MIC correlated with reduced virulence in Galleria mellonella.
  • Specific mutations in walK and rpoC cumulatively decreased virulence and increased DAP MIC.
  • mprF deletion attenuated virulence and increased susceptibility to DAP.
  • Clinical DAP(R) isolates showed reduced virulence compared to susceptible counterparts and were persistent in vivo.

Conclusions:

  • Genetic determinants of daptomycin resistance in Staphylococcus aureus significantly impact bacterial pathogenicity.
  • Daptomycin resistance mechanisms may involve trade-offs with virulence, but clinical isolates can remain persistent.
  • Understanding these genetic alterations is crucial for managing Staphylococcus aureus infections.
Keywords:
Galleria mellonellaS. aureusbacterial persistencemprFwalK

More Related Videos

A Fluorescence-based Method to Study Bacterial Gene Regulation in Infected Tissues07:10

A Fluorescence-based Method to Study Bacterial Gene Regulation in Infected Tissues

Published on: February 19, 2019

9.6K
Quantifying the Cytotoxicity of Staphylococcus aureus Against Human Polymorphonuclear Leukocytes12:27

Quantifying the Cytotoxicity of Staphylococcus aureus Against Human Polymorphonuclear Leukocytes

Published on: January 3, 2020

7.0K

Related Concept Videos

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...
57
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...
143
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...
100
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...
2.1K
Defense Against Bacterial Pathogens01:31

Defense Against Bacterial Pathogens

The human immune system is a complex network of cells, tissues, and organs that work together to defend the body against bacterial infections. It consists of various immune cells, each playing a specific role in the defense mechanism.
Phagocytes
Phagocytes are the frontline soldiers of the immune system. They include neutrophils and macrophages. Neutrophils are the most abundant type of white blood cell and are quickly mobilized to the site of infection. Macrophages are larger cells that patrol...
3.6K
Gene Regulation in Microbial Communities: Quorum Sensing01:28

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,...
923