|
| Status |
Public on Aug 25, 2008 |
| Title |
The Fusidic acid Stimulon of Staphylococcus aureus |
| Organism |
Staphylococcus aureus |
| Experiment type |
Expression profiling by array
|
| Summary |
Genome-wide transcriptional profiling studies of the growth of bacteria
with antimicrobial agents often reveals aspects of the drug-specific
protective bacterial response. Fusidic acid is a steroid antimicrobial that
inhibits protein synthesis by interfering with the release of elongation
factor G (EF-G) after it has functioned in the translocation step. Two
hundred and seventy two genes were both up- and down-regulated in a
fusidic acid-susceptible strain of Staphylococcus aureus following
challenge with 2 mg/L-1 fusidic acid for 15 min. Many genes altered by
fusidic acid challenge are associated with protein synthesis such as fusA,
which encodes EF-G which was up-regulated following exposure to the
drug. The Staphylococcus microarray meta-database which curates and
compares S. aureus transcriptome data revealed that the fusidic acid
stimulon has the greatest overlap with the S. aureus cold shock- and
stringent-responses. Six out of 9 autolysin genes making up the two
component YycFG regulon (ssaA1-ssaA4, isaA and sceD) were also
upregulated by fusidic acid; as were a carboxylesterase (est) and two
putative Emr-Qac-like multidrug efflux pumps (emr-qac1 and emr-qac2).
Genes down-regulated by fusidic acid induction encode a putative
secreted acid phosphatase (sapS) and a number of protease genes
(yjbG1, yjbG2, htrA1 and htrA2). Transcriptional analysis in conjunction
with mutant fusidic acid susceptibility experiments revealed that th45 e
virulence gene regulatory agr operon, a YycFG controlled peptidoglycan
hydrolase gene isaA and the proteases htrA1 and htrA2 are required for
the expression of wild-type levels of fusidic acid susceptibility.
|
| |
|
| Overall design |
S. aureus pangenome microarrays were utilized to determine transcriptome alterations occurring in S. aureus grown in the presence of fusidic acid. Total bacterial RNA was isolated as previously described from S. aureus strain SH1000 grown in Muellar-Hinton broth to an OD580nm of 1.0 (37°C, 200 rpm) and then induced with 2 mg/L-1 fusidic acid for 15 min. This RNA and RNA isolated from untreated SH1000 cultures were then converted to fluorescently-labeled cDNA and hybridized to S. aureus microarrays version 4 (NIAID's Pathogen Functional Genomics Resource Center). The Staphylococcus aureus microarray meta-database (SAMMD) curates data from various microarray experiments and allows for the comparison of microarray data obtained from different protocols and experiments. SAMMD was used to analyze the transcriptome generated from SH1000 grown in the presence of fusidic acid. Real-time PCR to confirm microarray data was performed. Following growth of SH1000 with and without fusidic acid addition at various time points, the cultures were serial diluted with fresh MHB, inoculated onto Muellar Hinton agar and the total surviving CFUs/ml were determined after 24 h.
|
| |
|
| Contributor(s) |
Delgado A, Zaman S, Muthaiyan A, Nagarajan V, Elasri MO, Wilkinson BJ, Gustafson JE |
| Citation(s) |
18786940 |
| |
| Submission date |
Jul 22, 2008 |
| Last update date |
Mar 20, 2012 |
| Contact name |
John E Gustafson, Arunachalam Muthaiyan |
| E-mail(s) |
jgustafs@nmsu.edu, amuthai@gmail.com
|
| Phone |
575-646-5660
|
| Fax |
575-646-5665
|
| Organization name |
New Mexico State University
|
| Department |
Department of Biology and Molecular Biology Program
|
| Lab |
Staph lab
|
| Street address |
PO Box 30001 Dept. 3AF
|
| City |
Las Cruces |
| State/province |
NM |
| ZIP/Postal code |
88003-8001 |
| Country |
USA |
| |
|
| Platforms (1) |
| GPL7072 |
JCVI PFGRC Staphylococcus aureus version 4 array |
|
| Samples (4)
|
| GSM306855 |
S. aureus Fusidic Acid Induction_A1 |
| GSM307131 |
S. aureus Fusidic Acid Induction_A2 |
| GSM307132 |
S. aureus Fusidic Acid Induction_B1 |
| GSM307133 |
S. aureus Fusidic Acid Induction_B2 |
|
| Relations |
| BioProject |
PRJNA113721 |
Less...
More...