Related Experiment Video

Updated: Jan 22, 2026

Multiplex PCR Assay for Typing of Staphylococcal Cassette Chromosome Mec Types I to V in Methicillin-resistant Staphylococcus aureus
09:03

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

Published on: September 5, 2013

12.3K

Regulation of the Staphylococcal Superantigen-Like Protein 1 Gene of Community-Associated Methicillin-Resistant

Daniel J Bretl1, Abdulaziz Elfessi2, Hannah Watkins1

  • 1Department of Microbiology, University of Wisconsin-La Crosse, La Crosse, WI 54601, USA.

Toxins
|July 7, 2019
PubMed

Insights

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) SSL1 gene expression is regulated by nutrient availability and crucial for early infection stages. This finding offers insights into CA-MRSA virulence and immune evasion strategies.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Infectious Diseases

Background:

  • Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) causes significant skin and soft tissue infections.
  • Staphylococcal superantigen-like (SSL) proteins are virulence factors involved in immune system evasion, but their roles in infection are not fully understood.
  • Investigating the regulation of SSL genes can provide insights into their functions.

Purpose of the Study:

  • To determine the transcriptional regulation of the staphylococcal superantigen-like 1 (ssl1) gene in CA-MRSA.
  • To understand how nutrient availability influences ssl1 gene expression.
  • To assess the role of ssl1 during the early stages of infection in a host.

Main Methods:

  • Construction of an ssl1 promoter::lux fusion.
  • Transformation into Staphylococcus aureus strains RN6390 and Newman.
  • Growth in defined minimal medium (DSM) and brain-heart infusion (BHI) broth to measure luminescence.
  • In vivo analysis using a mouse abscess model.

Main Results:

  • ssl1 transcription was upregulated and occurred earlier in DSM compared to BHI, indicating nutrient-dependent regulation.
  • A significant increase in ssl1 transcription was observed early during infection in the mouse abscess model.
  • These findings suggest ssl1 plays a role in the early stages of CA-MRSA infection.

Conclusions:

  • Nutrient availability is a key regulator of ssl1 gene expression in CA-MRSA.
  • The ssl1 gene is transcriptionally activated early during infection, highlighting its importance in the initial host-pathogen interaction.
  • SSL1 likely contributes to immune system evasion during the early phases of CA-MRSA infections.
Keywords:
defined minimal mediumgene regulationlux fusionmethicillin-resistant Staphylococcus aureusmouse abscesssuperantigen-like protein

More Related Videos

Subcutaneous Infection of Methicillin Resistant Staphylococcus Aureus MRSA12:18

Subcutaneous Infection of Methicillin Resistant Staphylococcus Aureus MRSA

Published on: February 9, 2011

23.6K
Methodology for the Study of Horizontal Gene Transfer in Staphylococcus aureus10:39

Methodology for the Study of Horizontal Gene Transfer in Staphylococcus aureus

Published on: March 10, 2017

17.3K

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,...
543
Covalently Linked Protein Regulators02:04

Covalently Linked Protein Regulators

Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein....
8.8K
Regulated Protein Degradation02:58

Regulated Protein Degradation

It is vital to regulate the activity of enzymatic as well as non-enzymatic proteins inside the cell. This can be achieved either through creating a balance between their rate of synthesis and degradation or regulating the intrinsic activity of the protein. Both these regulation mechanisms play an essential role in the normal functioning of cells.
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
8.8K
Regulated Protein Degradation02:58

Regulated Protein Degradation

3.1K
Gene Regulation During Sporulation01:17

Gene Regulation During Sporulation

Sporulation is a complex developmental process that allows certain Gram-positive bacteria, such as Bacillus subtilis and Clostridium species, to survive extreme environmental conditions. This process is tightly regulated by a series of signaling cascades and transcriptional controls, ensuring the formation of a highly resistant endospore.Sporulation is triggered by unfavorable conditions, such as nutrient depletion, and is governed by a phosphorelay system. One of the sensor kinases, such as...
457
Proteins: From Genes to Degradation02:11

Proteins: From Genes to Degradation

Within a biological system, the DNA encodes the RNA, and the nucleotide sequence in the RNA further defines the amino acid sequence in the protein. This is referred to as “The Central Dogma of Molecular Biology” - a term coined by Francis Crick.  Central dogma is a firm principle in biology that defines the flow of genetic information within any life form. The two fundamental steps in central dogma are - transcription and translation.
Transcription is the synthesis of RNA...
14.2K