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Vesiculation from Pseudomonas aeruginosa under SOS.
Reshma Maredia1, Navya Devineni, Peter Lentz
1Department of Biology, The University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA.
Thescientificworldjournal
|March 27, 2012
Summary
Antibiotic treatment can worsen bacterial infections by triggering the SOS response and outer membrane vesicle (OMV) production. Our study shows that the SOS response plays a role in this antibiotic-induced bacterial vesiculation and cytotoxicity.
Area of Science:
- Microbiology
- Bacterial Pathogenesis
- Antibiotic Resistance
Background:
- Antibiotic treatment can paradoxically exacerbate bacterial infections.
- This exacerbation is linked to the induction of the bacterial SOS response and increased production of outer membrane vesicles (OMVs).
- The precise relationship between the SOS response and antibiotic-induced vesiculation remains unclear.
Purpose of the Study:
- To investigate the association between the bacterial SOS response and antibiotic-induced outer membrane vesiculation.
- To determine the role of the SOS response in the increased cytotoxicity of Pseudomonas aeruginosa under antibiotic stress.
Main Methods:
- Comparative analysis of outer membrane vesicles (OMVs) from Pseudomonas aeruginosa wild-type and a LexA non-cleavable (lexAN) mutant strain.
- Induction of the SOS response using ciprofloxacin in the wild-type strain.
- Repression of the SOS response in the lexAN mutant strain.
- Quantification of OMV protein and lipid content.
- Assessment of OMV-mediated cytotoxicity.
- Subproteomic analysis of OMVs.
Main Results:
- Antibiotic treatment significantly increased OMV production, protein, and lipid content in both wild-type and lexAN strains.
- The increase in OMV production and cytotoxicity was significantly suppressed in the lexAN strain, where the SOS response was repressed.
- Subproteomic analysis revealed changes in OMV composition correlating with cellular physiology and cytotoxicity under SOS induction.
Conclusions:
- The bacterial SOS response is a significant factor contributing to the stimulation of outer membrane vesiculation during antibiotic treatment.
- Antibiotic-induced vesiculation, influenced by the SOS response, plays a role in bacterial cytotoxicity.
- These findings highlight a mechanism by which bacteria can adapt to antibiotic stress, potentially leading to increased virulence.
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