Sampling and diversity of Escherichia coli from the enteric microbiota in patients with Escherichia coli bacteraemia
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Published version
Supporting information
Author(s)
Type
Journal Article
Abstract
Objective
The increase in Escherichia coli bloodstream infections mandates better characterisation of the relationship between commensal and invasive isolates. This study adopted a simple approach to characterize E. coli in the gut reservoir from patients with either E. coli or other Gram-negative bacteraemia, or those without bacteraemia, establishing strain collections suitable for genomic investigation. Enteric samples from patients in the three groups were cultured on selective chromogenic agar. Genetic diversity of prevailing E. coli strains in gut microbiota was estimated by RAPD-PCR.
Results
Enteric samples from E. coli bacteraemia patients yielded a median of one E. coli RAPD pattern (range 1–4) compared with two (range 1–5) from groups without E. coli bacteraemia. Of relevance to large-scale clinical studies, observed diversity of E. coli among hospitalised patients was not altered by sample type (rectal swab or stool), nor by increasing the colonies tested from 10 to 20. Hospitalised patients demonstrated an apparently limited diversity of E. coli in the enteric microbiota and this was further reduced in those with E. coli bacteraemia. The reduced diversity of E. coli within the gut during E. coli bacteraemia raises the possibility that dominant strains may outcompete other lineages in patients with bloodstream infection.
The increase in Escherichia coli bloodstream infections mandates better characterisation of the relationship between commensal and invasive isolates. This study adopted a simple approach to characterize E. coli in the gut reservoir from patients with either E. coli or other Gram-negative bacteraemia, or those without bacteraemia, establishing strain collections suitable for genomic investigation. Enteric samples from patients in the three groups were cultured on selective chromogenic agar. Genetic diversity of prevailing E. coli strains in gut microbiota was estimated by RAPD-PCR.
Results
Enteric samples from E. coli bacteraemia patients yielded a median of one E. coli RAPD pattern (range 1–4) compared with two (range 1–5) from groups without E. coli bacteraemia. Of relevance to large-scale clinical studies, observed diversity of E. coli among hospitalised patients was not altered by sample type (rectal swab or stool), nor by increasing the colonies tested from 10 to 20. Hospitalised patients demonstrated an apparently limited diversity of E. coli in the enteric microbiota and this was further reduced in those with E. coli bacteraemia. The reduced diversity of E. coli within the gut during E. coli bacteraemia raises the possibility that dominant strains may outcompete other lineages in patients with bloodstream infection.
Date Issued
2019-06-13
Date Acceptance
2019-06-05
Citation
BMC Research Notes, 2019, 12
ISSN
1756-0500
Publisher
BioMed Central
Journal / Book Title
BMC Research Notes
Volume
12
Copyright Statement
© 2019 The Author(s). Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
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Sponsor
National Institute for Health Research
National Institute for Health Research
Grant Number
HPRU-2012-10047
HPRU-2012-10047
Subjects
Bacteraemia
Diversity
Escherichia coli
Microbiota
RAPD
Rectal swab
Sepsis
Stool
1199 Other Medical and Health Sciences
Bioinformatics
Publication Status
Published
Article Number
335