The Crohn’s disease-associated Escherichia coli strain LF82 rely on SOS and stringent responses to survive, multiply and tolerate antibiotics within macrophages

AbstractAdherent Invasive Escherichia coli (AIEC) strains recovered from Crohn's disease lesions survive and multiply within macrophages. A reference strain for this pathovar, AIEC LF82, forms microcolonies within phagolysosomes, an environment that prevents commensal E. coli multiplication. Little is known about the LF82 intracellular growth status, and signals leading to macrophage intra-vacuolar multiplication. We used single-cell analysis, genetic dissection and mathematical models to monitor the growth status and cell cycle regulation of intracellular LF82. We found that within macrophages, bacteria may replicate or undergo non-growing phenotypic switches. This switch results from stringent response firing immediately after uptake by macrophages or at later stages, following genotoxic damage and SOS induction during intracellular replication. Importantly, non-growers resist treatment with various antibiotics. Thus, intracellular challenges induce AIEC LF82 phenotypic heterogeneity and non-growing bacteria that could provide a reservoir for antibiotic-tolerant bacteria responsible for relapsing infections.

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Growth Control of Adherent-Invasive Escherichia coli (AIEC) by the Predator Bacteria Bdellovibrio bacteriovorus: A New Therapeutic Approach for Crohn’s Disease Patients

Microorganisms ◽

10.3390/microorganisms8010017 ◽

2019 ◽

Vol 8 (1) ◽

pp. 17 ◽

Cited By ~ 2

Author(s):

Giulia Bonfiglio ◽

Bruna Neroni ◽

Giulia Radocchia ◽

Arianna Pompilio ◽

Francesco Mura ◽

...

Keyword(s):

Escherichia Coli ◽

Crohn’S Disease ◽

Crohn's Disease ◽

Growth Control ◽

Coli Strain ◽

Bdellovibrio Bacteriovorus ◽

Gram Negative ◽

Intestinal Dysbiosis ◽

Predatory Bacteria ◽

Human Ecosystems

In Crohn’s disease (CD) patients, intestinal dysbiosis with an overgrowth of Proteobacteria, mainly Escherichia coli, has been reported. A new pathotype of E. coli, the adherent-invasive Escherichia coli strain (AIEC), has been isolated from the mucosae of CD patients. AIEC strains play an important role in CD pathogenesis, increasing intestinal mucosa damage and inflammation. Several studies have been undertaken to find possible strategies/treatments aimed at AIEC strain reduction/elimination from CD patients’ intestinal mucosae. To date, a truly effective strategy against AIEC overgrowth is not yet available, and as such, further investigations are warranted. Bdellovibrio bacteriovorus is a predator bacterium which lives by invading Gram-negative bacteria, and is usually present both in natural and human ecosystems. The aim of this study was to evaluate a novel possible strategy to treat CD patients’ mucosae when colonized by AIEC strains, based on the utilization of the Gram-negative predatory bacteria, B. bacteriovorus. The overall results indicate that B. bacteriovorus is able to interfere with important steps in the dynamics of pathogenicity of AIEC strains by its predatory activity. We indicate, for the first time, the possibility of counteracting AIEC strain overgrowth by exploiting what naturally occurs in microbial ecosystems (i.e., predation).

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The Crohn's disease-associated adherent-invasive Escherichia coli strain LF82 replicates in mature phagolysosomes within J774 macrophages

Cellular Microbiology ◽

10.1111/j.1462-5822.2005.00639.x ◽

2006 ◽

Vol 8 (3) ◽

pp. 471-484 ◽

Cited By ~ 92

Author(s):

Marie-Agnes Bringer ◽

Anne-Lise Glasser ◽

Ching-Hsuan Tung ◽

Stephane Meresse ◽

Arlette Darfeuille-Michaud

Keyword(s):

Escherichia Coli ◽

Crohn’S Disease ◽

Crohn's Disease ◽

Coli Strain

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The Oxidoreductase DsbA Plays a Key Role in the Ability of the Crohn's Disease-Associated Adherent-Invasive Escherichia coli Strain LF82 To Resist Macrophage Killing

Journal of Bacteriology ◽

10.1128/jb.00233-07 ◽

2007 ◽

Vol 189 (13) ◽

pp. 4860-4871 ◽

Cited By ~ 45

Author(s):

Marie-Agnès Bringer ◽

Nathalie Rolhion ◽

Anne-Lise Glasser ◽

Arlette Darfeuille-Michaud

Keyword(s):

Escherichia Coli ◽

Crohn’S Disease ◽

Crohn's Disease ◽

Epithelial Cells ◽

Intestinal Epithelial Cells ◽

Coli Strain ◽

Intestinal Epithelial ◽

Type 1 Pili ◽

K 12

ABSTRACT Adherent-invasive Escherichia coli (AIEC) isolated from Crohn's disease patients is able to adhere to and invade intestinal epithelial cells and to replicate in mature phagolysosomes within macrophages. Here, we show that the dsbA gene, encoding a periplasmic oxidoreductase, was required for AIEC strain LF82 to adhere to intestinal epithelial cells and to survive within macrophages. The LF82-ΔdsbA mutant did not express flagella and, probably as a consequence of this, did not express type 1 pili. The role of DsbA in adhesion is restricted to the loss of flagella and type 1 pili, as forced contact between bacteria and cells and induced expression of type 1 pili restored the wild-type phenotype. In contrast, the dsbA gene is essential for AIEC LF82 bacteria to survive within macrophages, irrespective of the loss of flagella and type 1 pilus expression, and the survival ability of LF82-ΔdsbA was as low as that of the nonpathogenic E. coli K-12, which was efficiently killed by macrophages. We also provide evidence that the dsbA gene is needed for LF82 bacteria to grow and survive in an acidic and nutrient-poor medium that partly mimics the harsh environment of the phagocytic vacuole. In addition, under such stress conditions dsbA transcription is highly up-regulated. Finally, the CpxRA signaling pathway does not play a role in regulation of dsbA expression in AIEC LF82 bacteria under conditions similar to those of mature phagolysosomes.

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