Replication of Crohn's Disease Mucosal E. coli Isolates inside Macrophages Correlates with Resistance to Superoxide and Is Dependent on Macrophage NF-kappa B Activation



Tawfik, Ahmed, Knight, Paul, Duckworth, Carrie A ORCID: 0000-0001-9992-7540, Pritchard, D Mark ORCID: 0000-0001-7971-3561, Rhodes, Jonathan M ORCID: 0000-0002-1302-260X and Campbell, Barry J ORCID: 0000-0002-7407-012X
(2019) Replication of Crohn's Disease Mucosal E. coli Isolates inside Macrophages Correlates with Resistance to Superoxide and Is Dependent on Macrophage NF-kappa B Activation. PATHOGENS, 8 (2). E74-.

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Abstract

Mucosa-associated Escherichia coli are increased in Crohn’s disease (CD) and colorectal cancer (CRC). CD isolates replicate within macrophages but the specificity of this effect for CD and its mechanism are unclear. Gentamicin exclusion assay was used to assess E. coli replication within J774.A1 murine macrophages. E. coli growth was assessed following acid, low-nutrient, nitrosative, oxidative and superoxide stress, mimicking the phagolysosome. Twelve of 16 CD E. coli isolates replicated >2-fold within J774.A1 macrophages; likewise for isolates from 6/7 urinary tract infection (UTI), 8/9 from healthy subjects, compared with 2/6 ulcerative colitis, 2/7 colorectal cancer and 0/3 laboratory strains. CD mucosal E. coli were tolerant of acidic, low-nutrient, nitrosative and oxidative stress. Replication within macrophages correlated strongly with tolerance to superoxide stress (rho = 0.44, p = 0.0009). Exemplar CD E. coli HM605 and LF82 were unable to survive within Nfκb1-/- murine bone marrow-derived macrophages. In keeping with this, pre-incubation of macrophages with hydrocortisone (0.6 µM for 24 h) caused 70.49 ± 12.11% inhibition of intra-macrophage replication. Thus, CD mucosal E. coli commonly replicate inside macrophages, but so do some UTI and healthy subject strains. Replication correlates with resistance to superoxide and is highly dependent on macrophage NF-κB signalling. This may therefore be a good therapeutic target.

Item Type: Article
Uncontrolled Keywords: Escherichia coli, Crohn's disease, macrophage, phagolysosome, superoxide, hydrocortisone, Nuclear factor kappa B
Depositing User: Symplectic Admin
Date Deposited: 12 Jun 2019 14:34
Last Modified: 19 Jan 2023 00:40
DOI: 10.3390/pathogens8020074
Open Access URL: https://doi.org/10.3390/pathogens8020074
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3045566