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Series GSE19953 Query DataSets for GSE19953
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
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.
 
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).
 
Contributor(s) Lee J, Cho M, Wood TK, Lee J
Citation(s) 21221972
Submission date Jan 19, 2010
Last update date Mar 08, 2019
Contact name Jintae Lee
E-mail(s) jtlee@ynu.ac.kr
Phone 82-53-810-2533
Organization name Yeungnam University
Department Chemical engineering
Lab Biotechnology
Street address 214-1 Daedong
City Gyeongsan-Si
State/province Gyeongsangbuk-Do
ZIP/Postal code 712-749
Country South Korea
 
Platforms (1)
GPL3154 [E_coli_2] Affymetrix E. coli Genome 2.0 Array
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
Relations
BioProject PRJNA122593

Download family Format
SOFT formatted family file(s) SOFTHelp
MINiML formatted family file(s) MINiMLHelp
Series Matrix File(s) TXTHelp

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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