Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Staphylococcal Skin Infections

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...

Mechanism of Antibiotic Resistance in MRSA

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...

Clinical Significance of Antibiotic Resistance

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...

Evolution of Microbial Genome

Evolution of Microbial Genome

Microbial genome evolution is a highly dynamic process shaped by continual gene gain and loss across species and strains. This genomic flexibility allows microorganisms to adapt rapidly to environmental pressures and interactions with other organisms. Central to understanding this diversity is the distinction between the core and pan genomes.The core genome comprises the genes shared by all sampled strains of a species, representing essential functions needed for fundamental cellular processes.

Other Stress Responses in Bacteria

Other Stress Responses in Bacteria

Bacteria have global regulatory systems that control several types of stress mechanisms. These include Pho regulon and the heat shock response, which are essential systems for environmental adaptation, such as nutrient limitation and proteotoxic stress. The Pho regulon and the heat shock response exemplify bacterial resilience, enabling rapid adaptation to fluctuating environmental conditions.Pho RegulonBacteria require phosphorus for essential cellular processes, including nucleic acid...

Gene Regulation in Microbial Communities: Quorum Sensing

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,...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Expanding the ABCA2-associated neurodevelopmental phenotype.

HGG advances·2026

Same author

Development and validation of a rabbit model of <i>Pseudomonas aeruginosa</i> hyperdynamic septic shock for preclinical drug development.

Antimicrobial agents and chemotherapy·2026

Same author

Polyclonal emergence of virulent, multidrug-resistant <i>Edwardsiella tarda</i> lineages associated with bacillary necrosis of <i>Pangasius</i> in striped catfish farms.

Applied and environmental microbiology·2026

Same author

Dried Blood Spots Capture a Wide Range of Metabolic Pathways and Biological Characteristics Associated with Fish Oil Supplementation, Fasting, and the Postprandial State.

Metabolites·2026

Same author

Dried blood spots capture a wide range of metabolic pathways and biological changes associated with exercise.

Metabolomics : Official journal of the Metabolomic Society·2025

Same author

Exploratory analysis of epilepsy biomarkers using untargeted metabolomics across multiple cohorts.

Frontiers in neurology·2025

Search research articles

Related Experiment Video

Updated: Jun 2, 2026

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

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

Published on: February 19, 2019

Global changes in Staphylococcus aureus gene expression in human blood.

Natalia Malachowa¹, Adeline R Whitney, Scott D Kobayashi

¹Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America.

|April 29, 2011

Summary

Staphylococcus aureus USA300 up-regulates gamma-hemolysin in human blood, impacting neutrophil lysis and bloodstream infection models. Functional redundancy among leukotoxins influences virulence.

More Related Videos

Staphylococcus aureus Growth using Human Hemoglobin as an Iron Source

Staphylococcus aureus Growth using Human Hemoglobin as an Iron Source

Published on: February 7, 2013

Related Experiment Videos

Last Updated: Jun 2, 2026

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

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

Published on: February 19, 2019

Staphylococcus aureus Growth using Human Hemoglobin as an Iron Source

Staphylococcus aureus Growth using Human Hemoglobin as an Iron Source

Published on: February 7, 2013

Area of Science:

Microbiology
Infectious Diseases
Molecular Biology

Background:

Staphylococcus aureus, particularly the USA300 strain, is a major cause of bloodstream infections globally.
The molecular mechanisms by which S. aureus survives in human blood and causes metastasis are not fully understood.

Purpose of the Study:

To investigate the USA300 transcriptome in human blood, serum, and TSB to identify virulence factors.
To determine the role of gamma-hemolysin (hlgABC) in S. aureus USA300 virulence, neutrophil lysis, and host survival.

Main Methods:

Transcriptome analysis of USA300 cultured in human blood, serum, and TSB.
Assessing neutrophil pore formation and lysis using wild-type and hlgABC-deletion strains.
Evaluating bacterial virulence in mouse bacteremia and skin infection models.

Main Results:

Genes for cytolytic toxins, including hlgABC, were significantly upregulated in human blood.
The hlgABC deletion mutant showed reduced neutrophil lysis and modestly reduced mortality in a mouse bacteremia model.
Functional redundancy was observed among two-component leukotoxins, suggesting a collective role in virulence.

Conclusions:

Gamma-hemolysin expression is induced by human blood and contributes to S. aureus USA300 virulence, particularly neutrophil lysis.
Leukotoxin redundancy may explain the limited contribution of individual toxins to immune evasion and overall virulence.
Specific growth conditions are critical for leukotoxin expression and subsequent virulence.