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| Status |
Public on Jan 12, 2012 |
| Title |
An antibiotic that inhibits a late step in wall teichoic acid biosynthesis induces the cell wall stress stimulon in Staphylococcus aureus |
| Organism |
Staphylococcus aureus |
| Experiment type |
Expression profiling by array
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| Summary |
Wall teichoic acids (WTAs) are phosphate-rich, sugar-based polymers attached to the cell walls of most Gram-positive bacteria. In Staphylococcus aureus, these anionic polymers regulate cell division, protect cells from osmotic stress, mediate host colonization, and mask enzymatically susceptible peptidoglycan bonds. Although WTAs are not required for survival in vitro, blocking the pathway at a late stage of synthesis is lethal. We recently discovered a novel antibiotic, targocil, that inhibits a late acting step in the WTA pathway. Its target is TarG, the transmembrane component of the ABC transporter (TarGH) that exports WTAs to the cell surface. Here we examine the effects of targocil on S. aureus using transmission electron microscopy (TEM) and gene expression profiling. We report that targocil treatment leads to multicellular clusters containing swollen cells displaying evidence of osmotic stress, strongly induces the cell wall stress stimulon, and reduces the expression of key virulence genes, including dltABCD and capsule genes. We conclude that WTA inhibitors that act at a late stage of the biosynthetic pathway may be useful as antibiotics, and we present evidence that they could be particularly useful in combination with beta-lactams.
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| Overall design |
Growth conditions for microarray analysis-For transcriptional profiling, an overnight S. aureus SH1000 culture was diluted (2% (v/v) into 20 mL TSB medium in a 50 mL Erlenmeyer flask and grown at 37 °C with shaking at 200 rpm. For the targocil treatment experiments, S. aureus was grown to an OD600 ~0.4 and challenged with 8x MIC of targocil dissolved in DMSO) for 30 min. Simultaneously, an equal amount of DMSO (final concentration 2% (v/v)) was added to the control culture, which was incubated along with the treated cultures. After 30 min, 5 mL aliquots were collected from control and treated cultures and used for toatl RNA preparation.
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| Contributor(s) |
Campbell J, Singh AK, Swoboda JG, Gilmore MS, Wilkinson BJ, Walker S |
| Citation(s) |
22290958 |
| |
| Submission date |
Dec 14, 2011 |
| Last update date |
May 02, 2012 |
| Contact name |
Arunachalam Muthaiyan, Brian Wilkinson |
| E-mail(s) |
amuthai@gmail.com, bjwilkin@ilstu.edu
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| Phone |
309-438-7244
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| URL |
http://www.bio.ilstu.edu/Wilkinson/
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| Organization name |
Illinois State University
|
| Department |
Biological Sciences
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| Lab |
Microbiology
|
| Street address |
Julian Hall
|
| City |
Normal |
| State/province |
IL |
| ZIP/Postal code |
61790 |
| Country |
USA |
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| Platforms (1) |
| GPL3866 |
TIGR Staphylococcus aureus version2 array |
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| Samples (6)
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| GSM861273 |
SH1000-targocil-30 min_rep1 (slide 14) |
| GSM861274 |
SH1000-targocil-30 min_rep1 (slide 15) |
| GSM861275 |
SH1000-targocil-30 min_rep2 (slide 20) |
| GSM861276 |
SH1000-targocil-30 min_rep2 (slide 22) |
| GSM861277 |
SH1000-targocil-30 min_rep3 (slide 504) |
| GSM861278 |
SH1000-targocil-30 min_rep3 (slide 556) |
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| Relations |
| BioProject |
PRJNA149619 |
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