Evidence map›Paper›PMID 35802671›Full record

ArticlePloS one2022

Phenotypic and genotypic characterisation of thymine auxotrophy in Escherichia coli isolated from a patient with recurrent bloodstream infection.

Aleksandra Jakovljev, Jan Egil Afset, Kjersti Haugum, Harald Otto Steinum, Torunn Gresdal Rønning, Ørjan Samuelsen, Christina Gabrielsen Ås

Open access · goldAbstract read
In one paragraph

Article in PloS one, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
0.5field-weighted citation impact, top 38% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed, 4 citations in OpenAlex.

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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors at 3 institutions in 1 country.

Aleksandra JakovljevDepartment of Medical Microbiology, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway.
Jan Egil AfsetDepartment of Medical Microbiology, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway.ORCID 0000-0003-2489-4179
Kjersti HaugumDepartment of Medical Microbiology, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway.
Harald Otto SteinumDepartment of Infectious Diseases, Clinic of Internal Medicine, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway.
Torunn Gresdal RønningDepartment of Medical Microbiology, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway.
Ørjan SamuelsenDepartment of Microbiology and Infection Control, Norwegian National Advisory Unit on Detection of Antimicrobial Resistance, University Hospital of North Norway, Tromsø, Norway.ORCID 0000-0002-5525-2614
Christina Gabrielsen ÅsDepartment of Medical Microbiology, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway.ORCID 0000-0002-9605-3283
Norwegian University of Science and Technology · NOSt Olav's University Hospital · NOUniversity Hospital of North Norway · NO

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

introductionThymine auxotrophic in vitro mutants of Escherichia coli were first reported in the mid-20th century. Later, thymine-dependent clinical strains of E. coli as well as other Enterobacterales, Enterococcus faecalis and Staphylococcus aureus have been recognized as the cause of persistent and recurrent infections.

objectivesThe aim of this study was to characterize the phenotype and investigate the molecular basis of thymine auxotrophy in ten E. coli isolates obtained at different time points from a patient with recurrent bloodstream infection (BSI) due to a chronic aortic graft infection treated with Trimethoprim/sulfamethoxazole (TMP-SMX).

methodsClinical data was obtained from hospital records. Growth characterization and antimicrobial susceptibility testing to TMP-SMX was performed on M9 agar and in MH broth with different thymine concentrations (0.5, 2, 5, 10 and 20 μg/mL), on Mueller-Hinton (MH) and blood agar. Whole genome sequencing (WGS) was performed on all E. coli isolates.

resultsE. coli were isolated from ten consecutive BSI episodes from a patient with chronic aortic graft infection. Six of these isolates were resistant to TMP-SMX when assayed on blood agar. Growth experiments with added thymine confirmed that these isolates were thymine-dependent (thy-), and revealed growth defects (slower growth rate and smaller colony size) in these isolates relative to thy+ isolates (n = 4). WGS indicated that all isolates were of the same clonal lineage of sequence type 7358. Genomic analysis revealed a G172C substitution in thyA in all TMP-SMX resistant isolates, while mutations affecting genes involved in the deoxyribose salvage pathway (deoB and deoC) were identified in eight isolates.

conclusionThis case highlights the risk of resistance development to TMP-SMX, especially for long-term treatment, and the possible pitfalls in detection of growth-deficient subpopulations from chronic infections, which could lead to treatment failure.

Indexed as

Escherichia coli InfectionsSepsisAgarAnti-Bacterial AgentsEscherichia coliHumansMicrobial Sensitivity TestsPhenotypeReinfectionThymineTrimethoprim, Sulfamethoxazole Drug CombinationAgarAnti-Bacterial AgentsThymineTrimethoprim, Sulfamethoxazole Drug Combination

Identifiers

PMID35802671
PMCPMC9269972
OpenAlexW4284965210

What OpenQuestion holds

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LicenceCC BY
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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.