Related Experiment Video
Updated: Jul 14, 2026
07:10
A Fluorescence-based Method to Study Bacterial Gene Regulation in Infected Tissues
Published on: February 19, 2019
[Monitoring genes encoding Panton-Valentine leukocidin in Staphylococcus aureus strains]
I Machová1, P Petrás, E Blazková
1Státní zdravotní ústav, Centrum epidemiologie a mikrobiologie, Národní referencní laborator pro stafylokoky, Praha. machova@szu.cz
Summary
Panton-Valentine leukocidin genes were detected in 8.1% of Staphylococcus aureus strains from Czech clinical specimens. These S. aureus strains are significant in skin infections.
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Context:
- Staphylococcus aureus is a significant human pathogen.
- Panton-Valentine leukocidin (PVL) is a key virulence factor associated with severe S. aureus infections.
- Detecting PVL genes is crucial for understanding S. aureus pathogenicity.
Purpose:
- To detect the genes encoding Panton-Valentine leukocidin (PVL) in S. aureus isolates from clinical specimens.
- To determine the prevalence of PVL-producing S. aureus in the Czech Republic.
Summary:
- 108 (8.1%) of 1336 S. aureus strains harbored genes for Panton-Valentine leukocidin.
- Only 11 of the PVL-positive strains were Methicillin-resistant Staphylococcus aureus (MRSA).
- Conventional and molecular methods, including PCR, were used for strain identification and gene detection.
Impact:
- PVL-producing S. aureus strains are implicated in serious infections, especially skin infections.
- The National Reference Laboratory for Staphylococci can detect PVL toxin production within two days.
- This rapid detection aids in clinical management and epidemiological surveillance of S. aureus infections.
Related Concept Videos
01:25Clinical 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...
01:28Regulation of Bacterial Virulence
Pathogenic bacteria employ a range of regulatory mechanisms to modulate the expression of virulence genes in response to environmental and host-derived signals. These mechanisms ensure that virulence factors are expressed only under favorable conditions, thereby optimizing infection and survival strategies.Mechanisms of Virulence RegulationKey regulatory strategies include:Two-Component Systems: These consist of a membrane-bound sensor kinase and a cytoplasmic response regulator. Environmental...
01:28Gene 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,...
01:20Determinants of Bacterial Pathogenicity and Virulence
Pathogenic bacteria employ a variety of strategies to establish infections, including the secretion of extracellular enzymes that act as potent virulence factors. These enzymes facilitate bacterial colonization of host tissues and help evade immune surveillance. By targeting structural components of host tissues and interfering with immune mechanisms, these enzymes play a pivotal role in disease progression.Extracellular Enzymes Facilitating Tissue Invasion: Several bacterial pathogens secrete...
01:25Mechanism 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...
01:29Staphylococcal 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...