C4 ‐dicarboxylates and L‐aspartate utilization by Escherichia coli K‐12 in the mouse intestine: L‐aspartate as a major substrate for fumarate respiration and as a nitrogen source

Escherichia coliMG1655, a K-12 strain, uses glycolytic nutrients exclusively to colonize the intestines of streptomycin-treated mice when it is the onlyE. colistrain present or when it is confronted withE. coliEDL933, an O157:H7 strain. In contrast,E. coliEDL933 uses glycolytic nutrients exclusively when it is the onlyE. colistrain in the intestine but switches in part to gluconeogenic nutrients when it colonizes mice precolonized withE. coliMG1655 (R. L. Miranda et al., Infect Immun 72:1666–1676, 2004,http://dx.doi.org/10.1128/IAI.72.3.1666-1676.2004). Recently, J. W. Njoroge et al. (mBio 3:e00280-12, 2012,http://dx.doi.org/10.1128/mBio.00280-12) reported thatE. coli86-24, an O157:H7 strain, activates the expression of virulence genes under gluconeogenic conditions, suggesting that colonization of the intestine with a probioticE. colistrain that outcompetes O157:H7 strains for gluconeogenic nutrients could render them nonpathogenic. Here we report thatE. coliNissle 1917, a probiotic strain, uses both glycolytic and gluconeogenic nutrients to colonize the mouse intestine between 1 and 5 days postfeeding, appears to stop using gluconeogenic nutrients thereafter in a large, long-term colonization niche, but continues to use them in a smaller niche to compete with invadingE. coliEDL933. Evidence is also presented suggesting that invadingE. coliEDL933 uses both glycolytic and gluconeogenic nutrients and needs the ability to perform gluconeogenesis in order to colonize mice precolonized withE. coliNissle 1917. The data presented here therefore rule out the possibility thatE. coliNissle 1917 can starve the O157:H7E. colistrain EDL933 of gluconeogenic nutrients, even thoughE. coliNissle 1917 uses such nutrients to compete withE. coliEDL933 in the mouse intestine.

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Utilization of γ-Aminobutyric Acid as the Sole Carbon and Nitrogen Source by Escherichia coli K-12 Mutants

Journal of Bacteriology ◽

10.1128/jb.109.2.835-843.1972 ◽

1972 ◽

Vol 109 (2) ◽

pp. 835-843 ◽

Cited By ~ 46

Author(s):

Shabtay Dover ◽

Yeheskel S. Halpern

Keyword(s):

Escherichia Coli ◽

Nitrogen Source ◽

Aminobutyric Acid ◽

Carbon And Nitrogen ◽

K 12

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Glycolytic and Gluconeogenic Growth of Escherichia coli O157:H7 (EDL933) and E. coli K-12 (MG1655) in the Mouse Intestine

Infection and Immunity ◽

10.1128/iai.72.3.1666-1676.2004 ◽

2004 ◽

Vol 72 (3) ◽

pp. 1666-1676 ◽

Cited By ~ 79

Author(s):

Regina L. Miranda ◽

Tyrrell Conway ◽

Mary P. Leatham ◽

Dong Eun Chang ◽

Wendy E. Norris ◽

...

Keyword(s):

Escherichia Coli ◽

Tricarboxylic Acid Cycle ◽

Initial Growth ◽

Intestinal Epithelial ◽

E Coli ◽

Intestinal Mucus ◽

Large Numbers ◽

Mouse Intestine ◽

K 12 ◽

Gluconeogenic Substrates

ABSTRACT Escherichia coli EDL933, an O157:H7 strain, is known to colonize the streptomycin-treated CD-1 mouse intestine by growing in intestinal mucus (E. A. Wadolkowski, J. A. Burris, and A. D. O'Brien, Infect. Immun. 58:2438-2445, 1990), but what nutrients and metabolic pathways are employed during colonization has not been determined. In this study, when the wild-type EDL933 strain was fed to mice along with an EDL933 ΔppsA ΔpckA mutant, which is unable to utilize tricarboxylic acid cycle intermediates and gluconeogenic substrates for growth, both strains colonized the mouse intestine equally well. Therefore, EDL933 utilizes a glycolytic substrate(s) for both initial growth and maintenance when it is the only E. coli strain fed to the mice. However, in the presence of large numbers of MG1655, a K-12 strain, it is shown that EDL933 utilizes a glycolytic substrate(s) for initial growth in the mouse intestine but appears to utilize both glycolytic and gluconeogenic substrates in an attempt to maintain colonization. It is further shown that MG1655 predominantly utilizes glycolytic substrates for growth in the mouse intestine whether growing in the presence or absence of large numbers of EDL933. Data are presented showing that although small numbers of EDL933 grow to large numbers in the intestine in the presence of large numbers of MG1655 when both strains are fed to mice simultaneously, precolonization with MG1655 affords protection against subsequent colonization by EDL933. Moreover, in mice that are precolonized with EDL933, small numbers of MG1655 are able to grow rapidly in the intestine and EDL933 is eliminated. In situ hybridization experiments using E. coli-specific rRNA probes showed that while MG1655 is found only in mucus, EDL933 is found both in mucus and closely associated with intestinal epithelial cells. The data are discussed with respect to competition for nutrients and to the protection that some intestinal commensal E. coli strains might afford against infection by O157:H7 strains.

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