Journal article
Indole Production Promotes Escherichia coli Mixed-Culture Growth with Pseudomonas aeruginosa by Inhibiting Quorum Signaling
Applied and environmental microbiology, Vol.78(2), pp.411-419
01/2012
DOI: 10.1128/AEM.06396-11
PMCID: PMC3255741
PMID: 22101045
Abstract
Indole production by
Escherichia coli
, discovered in the early 20th century, has been used as a diagnostic marker for distinguishing
E. coli
from other enteric bacteria. By using transcriptional profiling and competition studies with defined mutants, we show that cyclic AMP (cAMP)-regulated indole formation is a major factor that enables
E. coli
growth in mixed biofilm and planktonic populations with
Pseudomonas aeruginosa
. Mutants deficient in cAMP production (
cyaA
) or the cAMP receptor gene (
crp
), as well as indole production (
tnaA
), were not competitive in coculture with
P. aeruginosa
but could be restored to wild-type competitiveness by supplementation with a physiologically relevant indole concentration.
E. coli
sdiA
mutants, which lacked the receptor for both indole and
N
-acyl-homoserine lactones (AHLs), showed no change in competitive fitness, suggesting that indole acted directly on
P. aeruginosa
. An
E. coli
tnaA
mutant strain regained wild-type competiveness if grown with
P. aeruginosa
AHL synthase (
rhlI
and
rhlI lasI
) mutants. In contrast to the wild type,
P. aeruginosa
AHL synthase mutants were unable to degrade indole. Indole produced during mixed-culture growth inhibited pyocyanin production and other AHL-regulated virulence factors in
P. aeruginosa
. Mixed-culture growth with
P. aeruginosa
stimulated indole formation in
E. coli
cpdA
, which is unable to regulate cAMP levels, suggesting the potential for mixed-culture gene activation via cAMP. These findings illustrate how indole, an early described feature of
E. coli
central metabolism, can play a significant role in mixed-culture survival by inhibiting quorum-regulated competition factors in
P. aeruginosa
.
Details
- Title: Subtitle
- Indole Production Promotes Escherichia coli Mixed-Culture Growth with Pseudomonas aeruginosa by Inhibiting Quorum Signaling
- Creators
- Weihua Chu - Department of Microbiology, School of Life Science and Technology, China Pharmaceutical University, Nanjing, ChinaTesfalem R Zere - Department of Biology, Texas State University—San Marcos, San Marcos, Texas, USAMary M Weber - Department of Microbial and Molecular Pathogenesis, Texas A&M Health Sciences Center, College Station, Texas, USAThomas K Wood - Department of Chemical Engineering, Texas A&M University, College Station, Texas, USAMarvin Whiteley - Section of Molecular Genetics and Microbiology, University of Texas at Austin, Austin, Texas, USABenjamin Hidalgo-Romano - Department of Biology, Texas State University—San Marcos, San Marcos, Texas, USAErnesto Valenzuela - Department of Biology, Texas State University—San Marcos, San Marcos, Texas, USARobert J. C McLean - Department of Biology, Texas State University—San Marcos, San Marcos, Texas, USA
- Resource Type
- Journal article
- Publication Details
- Applied and environmental microbiology, Vol.78(2), pp.411-419
- Publisher
- American Society for Microbiology
- DOI
- 10.1128/AEM.06396-11
- PMID
- 22101045
- PMCID
- PMC3255741
- ISSN
- 0099-2240
- eISSN
- 1098-5336
- Language
- English
- Date published
- 01/2012
- Academic Unit
- Molecular Physiology and Biophysics; Microbiology and Immunology
- Record Identifier
- 9984083283602771
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