Related Experiment Video

Updated: Mar 15, 2026

A Fluorescence-based Method to Study Bacterial Gene Regulation in Infected Tissues
07:10

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

Published on: February 19, 2019

9.6K

PSM-Mec-A Virulence Determinant that Connects Transcriptional Regulation, Virulence, and Antibiotic Resistance in

Li Qin1, Joshua W McCausland2, Gordon Y C Cheung2

  • 1Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of HealthBethesda, MD, USA; Department of Dermatology, Wuhan No. 1 Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhan, China.

Frontiers in Microbiology
|September 7, 2016
PubMed

Insights

Phenol-soluble modulin-mec (PSM-mec) is a unique toxin found in Staphylococcus. Its gene

Area of Science:

  • Microbiology
  • Molecular Biology
  • Bacterial Pathogenesis

Background:

  • Phenol-soluble modulins (PSMs) are amphipathic, alpha-helical peptide toxins secreted by Staphylococcus species.
  • Most PSMs are encoded in the core genome, but PSM-mec is an exception, encoded within specific SCCmec elements associated with methicillin resistance.
  • The psm-mec locus includes genes for both the PSM-mec peptide toxin and a regulatory RNA molecule.

Purpose of the Study:

  • To summarize the functional properties of the PSM-mec peptide and its associated regulatory RNA.
  • To elucidate the roles of PSM-mec and its RNA in Staphylococcus pathogenesis and physiology.
  • To highlight the impact of the psm-mec locus on virulence, including cytolytic capacity, antibiotic resistance, and immune evasion.

Main Methods:

  • Literature review and synthesis of existing research on PSM-mec and the psm-mec locus.
  • Analysis of the genetic location of psm-mec within SCCmec elements.
  • Examination of strain-dependent effects attributed to PSM-mec peptide and RNA.

Main Results:

  • PSM-mec is a cytolytic toxin, and its locus influences multiple Staphylococcus aureus virulence traits, including methicillin resistance and biofilm formation.
  • The psm-mec locus impacts the expression of other virulence factors, contributing to immune evasion and disease.
  • Observed strain-dependent effects suggest differential contributions of PSM-mec peptide versus RNA to staphylococcal physiology and pathogenesis.

Conclusions:

  • The PSM-mec toxin and its regulatory RNA play significant, albeit strain-dependent, roles in staphylococcal pathogenesis.
  • Understanding the dual function of the psm-mec locus is crucial for comprehending Staphylococcus virulence and developing targeted interventions.
  • Further research is needed to fully delineate the specific mechanisms by which PSM-mec peptide and RNA modulate virulence.
Keywords:
PSM-mecSCCmecStaphylococcus aureusStaphylococcus epidermidisphenol-soluble modulinregulatory RNAvirulence

More Related Videos

Multiplex PCR Assay for Typing of Staphylococcal Cassette Chromosome Mec Types I to V in Methicillin-resistant Staphylococcus aureus09:03

Multiplex PCR Assay for Typing of Staphylococcal Cassette Chromosome Mec Types I to V in Methicillin-resistant Staphylococcus aureus

Published on: September 5, 2013

12.4K
A Tandem Liquid Chromatography–Mass Spectrometry-based Approach for Metabolite Analysis of Staphylococcus aureus08:03

A Tandem Liquid Chromatography–Mass Spectrometry-based Approach for Metabolite Analysis of Staphylococcus aureus

Published on: March 28, 2017

10.7K

Related Concept Videos

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,...
833
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...
1.8K
Global Regulatory Systems01:28

Global Regulatory Systems

Global regulatory systems in bacteria enable rapid and coordinated responses to environmental changes by integrating sensory inputs with gene expression, ensuring efficient adaptation to fluctuating conditions. Key global regulatory mechanisms include regulons, two-component systems, sigma factors, and secondary messengers.Regulons and Global RegulatorsA regulon is a collection of genes and operons controlled by a common global regulator. These regulators enable bacteria to prioritize resource...
840
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...
3.3K
Prokaryotic Transcriptional Activators and Repressors01:58

Prokaryotic Transcriptional Activators and Repressors

The organization of prokaryotic genes in their genome is notably different from that of eukaryotes. Prokaryotic genes are organized, such that the genes for proteins involved in the same biochemical process or function are located together in groups. This group of genes, along with their regulatory elements, are collectively known as an operon. The functional genes in an operon are transcribed together to give a single strand of mRNA known as polycistronic mRNA.
Transcription of prokaryotic...
26.0K
Stringent Response in E. coli01:23

Stringent Response in E. coli

Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs...
452