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Published on: March 28, 2017
Transcriptomic Adjustments of Staphylococcus aureus COL (MRSA) Forming Biofilms Under Acidic and Alkaline Conditions
Georgios Efthimiou1, George Tsiamis2, Milton A Typas1
1Department of Genetics and Biotechnology, Faculty of Biology, National and Kapodistrian University of Athens, Athens, Greece.
Abstract:
Methicillin-resistant Staphylococcus aureus (MRSA) strains are important human pathogens and a significant health hazard for hospitals and the food industry. They are resistant to β-lactam antibiotics including methicillin and extremely difficult to treat. In this study, we show that the Staphylococcus aureus COL (MRSA) strain, with a known complete genome, can easily survive and grow under acidic and alkaline conditions (pH5 and pH9, respectively), both planktonically and as a biofilm. A microarray-based analysis of both planktonic and biofilm cells was performed under acidic and alkaline conditions showing that several genes are up- or down-regulated under different environmental conditions and growth modes. These genes were coding for transcription regulators, ion transporters, cell wall biosynthetic enzymes, autolytic enzymes, adhesion proteins and antibiotic resistance factors, most of which are associated with biofilm formation. These results will facilitate a better understanding of the physiological adjustments occurring in biofilm-associated S. aureus COL cells growing in acidic or alkaline environments, which will enable the development of new efficient treatment or disinfection strategies.
Insights
Methicillin-resistant Staphylococcus aureus (MRSA) survives in acidic and alkaline conditions. Gene expression changes in MRSA biofilms provide insights into survival strategies and potential new treatments.
Area of Science:
- Microbiology
- Molecular Biology
- Pathogen Research
Background:
- Methicillin-resistant Staphylococcus aureus (MRSA) is a major human pathogen causing significant health risks in healthcare and food industries.
- MRSA's resistance to beta-lactam antibiotics makes infections extremely challenging to treat.
- Understanding MRSA's adaptability is crucial for developing effective control strategies.
Purpose of the Study:
- To investigate the survival and growth of MRSA under extreme pH conditions (acidic and alkaline).
- To analyze gene expression changes in planktonic and biofilm MRSA cells exposed to varying pH levels.
- To identify genes involved in MRSA's physiological adaptation to environmental stress.
Main Methods:
- The study utilized the well-characterized Staphylococcus aureus COL (MRSA) strain.
- MRSA survival and growth were assessed under planktonic and biofilm conditions at pH 5 and pH 9.
- Microarray analysis was performed on MRSA cells under these different conditions to examine gene expression profiles.
Main Results:
- The MRSA COL strain demonstrated robust survival and growth in both acidic (pH 5) and alkaline (pH 9) environments.
- Microarray analysis revealed significant up- and down-regulation of various genes in response to pH stress and growth modes.
- Affected genes included those involved in transcription regulation, ion transport, cell wall biosynthesis, autolysis, adhesion, and antibiotic resistance, many linked to biofilm formation.
Conclusions:
- MRSA exhibits remarkable adaptability to extreme pH conditions, both as planktonic cells and biofilms.
- Environmental pH significantly influences the gene expression of MRSA, particularly genes associated with biofilm formation and stress response.
- These findings offer a foundation for developing novel therapeutic and disinfection strategies targeting MRSA survival mechanisms.
