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Status |
Public on Jan 19, 2011 |
Title |
Mechanisms of Biofilm Formation in Two Escherichia coli O157:H7 Lineages |
Organism |
Escherichia coli |
Experiment type |
Expression profiling by array
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Summary |
Two lineages of enterohemorrhagic (EHEC) Escherichia coli O157:H7 (EDL933, Stx1+ and Stx2+) and 86-24 (Stx2+) were investigated in regards to biofilm formation on an abiotic surface. Strikingly, EDL933 strain formed a robust biofilm while 86-24 strain formed no biofilm on either a polystyrene plate or a polyethylene tube. To identify the genetic mechanisms of different biofilm formation in two EHEC strains, DNA microarrays were first performed and phenotypic assays were followed. In the comparison of the EDL933 strain versus 86-24 strain, genes (csgBAC and csgDEFG) involved in curli biosynthesis were significantly induced while genes (trpLEDCB and mtr) involved in indole signaling were repressed. Additionally, a dozen of phage genes were differentially present between two strains. Curli assays using a Congo red plate and scanning electron microscopy corroborate the microarray data as the EDL 933 strain produces a large amount of curli, while 86-24 forms much less curli. Also, the indole production in the EDL933 was 2-times lower than that of 86-24. It was known that curli formation positively regulates and indole negatively regulates biofilm formation of EHEC. Hence, it appears that less curli formation and high indole production in the 86-24 strain are majorly responsible for no biofilm formation.
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Overall design |
For the microarray experiments, E. coli O157:H7 EDL933 and 86-24 were inoculated in 25 ml of LB in 250 ml shake flasks with overnight cultures that were diluted 1:100. Cells were shaken at 250 rpm and 37°C for an absorbance of 4.0 at 600 nm. Cells were immediately chilled with dry ice and 95% ethanol (to prevent RNA degradation) for 30 sec before centrifugation in 50 ml centrifuge tubes at 13,000 g for 2 min; cell pellets were frozen immediately with dry ice and stored -80°C. RNA was isolated using Qiagen RNeasy mini Kit (Valencia, CA, USA). RNA quality was assessed by Agilent 2100 bioanalyser using the RNA 6000 Nano Chip (Agilent Technologies, Amstelveen, The Netherlands), and quantity was determined by ND-1000 Spectrophotometer (NanoDrop Technologies, Inc., DE, USA).
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Contributor(s) |
Lee J, Cho M, Wood TK, Lee J |
Citation(s) |
21221972 |
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Submission date |
Jan 19, 2010 |
Last update date |
Mar 08, 2019 |
Contact name |
Jintae Lee |
E-mail(s) |
[email protected]
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Phone |
82-53-810-2533
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Organization name |
Yeungnam University
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Department |
Chemical engineering
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Lab |
Biotechnology
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Street address |
214-1 Daedong
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City |
Gyeongsan-Si |
State/province |
Gyeongsangbuk-Do |
ZIP/Postal code |
712-749 |
Country |
South Korea |
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Platforms (1) |
GPL3154 |
[E_coli_2] Affymetrix E. coli Genome 2.0 Array |
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Samples (2) |
GSM498647 |
E. coli O157:H7 EDL933 in LB at 37oC at OD 4.0 |
GSM498648 |
E. coli O157:H7 86-24 in LB at 37oC at OD 4.0 |
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Relations |
BioProject |
PRJNA122593 |
Supplementary file |
Size |
Download |
File type/resource |
GSE19953_RAW.tar |
1.6 Mb |
(http)(custom) |
TAR (of CEL, CHP) |
Processed data included within Sample table |
Processed data provided as supplementary file |
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