Evidence map›Paper›PMID 41861630›Full record

ArticlePoultry science2026

Antibiotic susceptibility and resistance genes in Escherichia coli from broilers reared in a low-antibiotic-use production system.

Homayoon Davam, Désirée S Jansson, Emma Nord, Jesper Rydén, Ingrid Hansson

Abstract read
In one paragraph

Article in Poultry science, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
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

1 citing paper in PubMed.

  1. Article
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

5 authors.

Homayoon DavamDepartment of Animal Biosciences, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden. Electronic address: homayoon.davam@slu.se.
Désirée S JanssonDepartment of Clinical Sciences, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden.
Emma NordDepartment of Microbiology, Swedish Veterinary Agency, SE-751 89 Uppsala, Sweden.
Jesper RydénDepartment of Energy and Technology, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden.
Ingrid HanssonDepartment of Animal Biosciences, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Antimicrobial resistance (AMR) is a major global concern for animal and human health. This study investigated the occurrence and patterns of AMR in Escherichia coli (E. coli) isolated from Swedish broiler flocks reared under low-antibiotic-use conditions. During routine necropsy examinations of 80 broilers from 40 flocks with increased mortality associated with colibacillosis, liver samples were collected for bacteriological analysis. E. coli isolated from the liver were classified as clinical E. coli. In addition, boot sock samples were taken to collect feces from the litter of 60 broiler flocks with no signs of disease or increased mortality. E. coli isolates (n = 109) obtained from boot sock samples were classified as non-clinical E. coli. Susceptibility to 15 antibiotics was assessed using broth microdilution, and resistance-associated genes and mutations were identified through whole-genome sequencing (WGS). Overall resistance was low, with all isolates susceptible to 9 of the 15 tested antibiotics: meropenem, azithromycin, amikacin, gentamicin, tigecycline, ceftazidime, cefotaxime, chloramphenicol, and colistin. Resistance was significantly more frequent in non-clinical than clinical isolates for the six antibiotics with detected resistance (P < 0.05) and was strongly correlated with the presence of known AMR genes or mutations. Among clinical isolates, 93.7% were fully susceptible to all tested antibiotics, compared with 49.5% of non-clinical isolates. The highest resistance rates were observed in non-clinical isolates against ampicillin (34%), sulfamethoxazole (32.1%), and trimethoprim (28.4%). The results of this study indicate that in low-antibiotic-use production systems, factors beyond direct antibiotic use-such as horizontal gene transfer, vertical transmission, and environmental contamination-may contribute to AMR dissemination. Higher AMR rates in non-clinical isolates suggest that these isolates may serve as reservoirs of resistance genes. This highlights the importance of monitoring commensal E. coli and farm environments to support AMR mitigation and sustainable broiler production.

Indexed as

Anti-Bacterial AgentsChickensDrug Resistance, BacterialEscherichia coliEscherichia coli InfectionsPoultry DiseasesAnimal HusbandryAnimalsMicrobial Sensitivity TestsSwedenAnti-Bacterial AgentsAntimicrobial resistanceBroilerEscherichia coliReservoirResistance gene

Identifiers

PMID41861630
PMCPMC13018936

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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.