Difference between revisions of "PMID:16385049"

From OMPwiki
(Materials and Methods Used)
Line 38: Line 38:
 
== Materials and Methods Used ==
 
== Materials and Methods Used ==
 
*[[:Category:Biofilm, 96-well Assay (Herzberg et al. 2006)|Biofilm, 96-well Assay (Herzberg et al. 2006)]]  
 
*[[:Category:Biofilm, 96-well Assay (Herzberg et al. 2006)|Biofilm, 96-well Assay (Herzberg et al. 2006)]]  
**[[:Category:Crystal violet|Crystal violet]]
 
 
*[[:Category:Biofilm, Flow Cell Assay (Herzberg et al. 2006)|Biofilm, Flow Cell Assay (Herzberg et al. 2006)]]
 
*[[:Category:Biofilm, Flow Cell Assay (Herzberg et al. 2006)|Biofilm, Flow Cell Assay (Herzberg et al. 2006)]]
 
*[[:Category:COMSTAT|COMSTAT]]
 
*[[:Category:COMSTAT|COMSTAT]]

Revision as of 17:24, 21 March 2012

Citation

Herzberg, M, Kaye, IK, Peti, W and Wood, TK (2006) YdgG (TqsA) controls biofilm formation in Escherichia coli K-12 through autoinducer 2 transport.J. Bacteriol. 188:587-98

Abstract

YdgG is an uncharacterized protein that is induced in Escherichia coli biofilms. Here it is shown that deletion of ydgG decreased extracellular and increased intracellular concentrations of autoinducer 2 (AI-2); hence, YdgG enhances transport of AI-2. Consistent with this hypothesis, deletion of ydgG resulted in a 7,000-fold increase in biofilm thickness and 574-fold increase in biomass in flow cells. Also consistent with the hypothesis, deletion of ydgG increased cell motility by increasing transcription of flagellar genes (genes induced by AI-2). By expressing ydgG in trans, the wild-type phenotypes for extracellular AI-2 activity, motility, and biofilm formation were restored. YdgG is also predicted to be a membrane-spanning protein that is conserved in many bacteria, and it influences resistance to several antimicrobials, including crystal violet and streptomycin (this phenotype could also be complemented). Deletion of ydgG also caused 31% of the bacterial chromosome to be differentially expressed in biofilms, as expected, since AI-2 controls hundreds of genes. YdgG was found to negatively modulate expression of flagellum- and motility-related genes, as well as other known products essential for biofilm formation, including operons for type 1 fimbriae, autotransporter protein Ag43, curli production, colanic acid production, and production of polysaccharide adhesin. Eighty genes not previously related to biofilm formation were also identified, including those that encode transport proteins (yihN and yihP), polysialic acid production (gutM and gutQ), CP4-57 prophage functions (yfjR and alpA), methionine biosynthesis (metR), biotin and thiamine biosynthesis (bioF and thiDFH), anaerobic metabolism (focB, hyfACDR, ttdA, and fumB), and proteins with unknown function (ybfG, yceO, yjhQ, and yjbE); 10 of these genes were verified through mutation to decrease biofilm formation by 40% or more (yfjR, bioF, yccW, yjbE, yceO, ttdA, fumB, yjiP, gutQ, and yihR). Hence, it appears YdgG controls the transport of the quorum-sensing signal AI-2, and so we suggest the gene name tqsA.

Links

PubMed Online version:10.1128/JB.188.2.587-598.2006

Keywords

Biofilms; Biological Transport; Escherichia coli K12; Escherichia coli Proteins; Gene Deletion; Genes, Bacterial; Homoserine; Lactones; Transcription, Genetic

Main Points of the Paper

Please summarize the main points of the paper.

Materials and Methods Used

Phenotype Annotations

See Help:AnnotationTable for details on how to edit this table.

Species Taxon ID Strain Gene (if known) OMP Phenotype Details Evidence Notes

Escherichia coli

delydgG

increased biofilm formation

Other

assayed in 96-well plates when glucose was added to the medium

Staining

crystal violet assay

Escherichia coli

delydgG

increased biofilm formation

Other

assayed in continuous flow system

Microscopy

Figure 1

Escherichia coli

del ydgG

flat biofilm formation

Morphology

assayed in continuous flow system

Microscopy

Figure 1

Escherichia coli

del ydgG

biofilm morphology- large, irregularly shaped, smooth masses containing random protrusions

Morphology

assayed in continuous flow system

Microscopy

Figure 1

Escherichia coli

del ydgG

biofilm architecture- increased biomass

Morphology

increased biomass 574-fold after 24 hours

Microscopy

using COMSTAT computer program

Escherichia coli

del ydgG

increased substratum coverage

Morphology

increased substratum coverage 10-fold after 24 hours

Microscopy

using COMSTAT computer program

Escherichia coli

del ydgG

biofilm architecture-increased mean thickness

Morphology

increased mean thickness 7,000-fold after 24 hours

Microscopy

using COMSTAT computer program

Escherichia coli

del ydgG

biofilm architecture-decreased roughness coefficient

Morphology

decreased roughness coefficient 12-fold after 24 hours

Microscopy

using COMSTAT computer program

Escherichia coli

del ydgG

increase in swimming motility

Motility

6-fold increase compared to wt

Plating Assay

Escherichia coli

del ydgG

increased transcription of other genes

Expression

increased the transcription of the quorum-sensing response regulator of flagellum genes (qseB), flagellar synthesis genes (flhD, fliA, and fliC), and a motility gene (motA)

Other

Figure 2- beta-galactosidase activity

Escherichia coli

del ydgG

decreased extracellular AI-2 activity

Other

Other

Escherichia coli

del ydgG

increased intracellular AI-2 activity

Other

Other

Figure 3- lsrACDBFG transcription

Escherichia coli

del ydgG

  • decreased resistance to antimicrobials
  • decreased drug susceptibility
  • increased sensitivity to antimicrobials

Sensitivity to

crystal violet, spectinomycin, streptomycin sulfate, 2,6, dichloroquinone-4-chlorimide, chloramphenicol, amoxicillin

Plating Assay

MIC comparisons

Escherichia coli

del ydgG

change in differential gene expression in biofilms-

Expression

  • 31% of genes differentially induced
  • 8% of genes differentially repressed

Tables 2 and 3

Notes

References

See Help:References for how to manage references in OMPwiki.