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Updated: May 28, 2026
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Development and Assessment of Intracellular Infection Models for Staphylococcus aureus
Published on: January 17, 2025
Reduced Oxygen Condition Is Associated with Genome-Wide Expression Changes in Mastitis-Lineage Staphylococcus aureus
Kamaleldin B Said1, Marcus B Jones2, Rosslyn Maybank3
1Department of Pathology, College of Medicine, University of Ha'il, Ha'il 55473, Saudi Arabia.
International Journal of Molecular Sciences
|May 27, 2026
Summary
Reduced oxygen significantly alters Staphylococcus aureus transcription within bovine mammary epithelial cells, impacting virulence and adaptation pathways. This study identifies key transcriptional shifts for potential therapeutic targets.
Area of Science:
- Microbiology and Immunology
- Bovine Health and Disease
- Molecular Biology
Background:
- Bovine mastitis caused by Staphylococcus aureus is a major economic and public health concern.
- Understanding host-microenvironmental interactions, particularly oxygen levels, is crucial for elucidating S. aureus intramammary adaptation.
- Limited knowledge exists on how reduced oxygen influences S. aureus gene expression within mammary epithelial cells.
Purpose of the Study:
- To investigate oxygen-associated transcriptional changes in Staphylococcus aureus internalized into bovine mammary epithelial cells (MECs).
- To identify functional categories enriched under normal and reduced oxygen conditions.
- To reveal candidate pathways for S. aureus intramammary adaptation and potential therapeutic targets.
Main Methods:
- Bovine MAC-T cell monolayers were infected with a bovine mastitis isolate of S. aureus under normal and reduced oxygen conditions.
- High-throughput qRT-PCR was used to profile genome-wide transcriptional changes.
- Expression data were mapped to curated BioQT roles for functional interpretation, with non-reacted bacteria serving as controls.
Main Results:
- Under normal oxygen, 211 loci were upregulated and 99 downregulated, affecting cellular processes, transport, regulation, and energy metabolism.
- Under reduced oxygen, 53 loci were upregulated and 35 downregulated, with enriched functions in pathogenesis/toxins and nucleotide biosynthesis.
- Reduced oxygen conditions led to a narrower transcriptional response, enriched in toxin/pathogenesis and iron/cation-associated annotations.
Conclusions:
- Oxygen levels significantly modulate the transcriptional response of intramammary S. aureus within bovine MECs.
- Reduced oxygen promotes virulence-associated gene expression, suggesting a role in host adaptation.
- These findings highlight potential diagnostic markers and anti-virulence strategies against S. aureus mastitis.
Keywords:
bovine mastitisgenome-wide expressionintramammary Staphylococcus aureusmammary epithelial cellsreduced oxygenMore Related Videos
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