Evidence map›Paper›PMID 41673559›Full record

ArticleBMC microbiology2026

Conjugation frequency of ESBL- and pAmpC- E. coli in broiler chickens in vivo and in vitro.

Diana Vargas, Roswitha Merle, Anika Friese, Uwe Roesler, Caroline Robé

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Article in BMC microbiology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

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2 · The registry

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

5 authors.

Diana VargasInstitute of Animal Hygiene and Environmental Health, Veterinary Centre for Resistance Research, Freie Universität Berlin, Berlin, Germany. diana.vargas.gallo@fu-berlin.de.
Roswitha MerleInstitute of Veterinary Epidemiology and Biostatistics, Veterinary Centre for Resistance Research, Freie Universität Berlin, Berlin, Germany.
Anika FrieseInstitute of Animal Hygiene and Environmental Health, Veterinary Centre for Resistance Research, Freie Universität Berlin, Berlin, Germany.
Uwe RoeslerInstitute of Animal Hygiene and Environmental Health, Veterinary Centre for Resistance Research, Freie Universität Berlin, Berlin, Germany.
Caroline RobéInstitute of Animal Hygiene and Environmental Health, Veterinary Centre for Resistance Research, Freie Universität Berlin, Berlin, Germany.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundPlasmid-mediated conjugation is a major form of horizontal gene transfer (HGT), facilitating dissemination of antimicrobial resistance (AMR) and the emergence of multi-drug-resistant (MDR) strains. In poultry, Escherichia coli producing extended-spectrum β-lactamases (ESBL) and plasmid-mediated AmpC β-lactamase (pAmpC) enzymes are common and contribute to antibiotic resistance. Additionally, plasmid-mediated colistin resistance gene mcr-1 in poultry requires attention, as it is a last-resort antibiotic in human medicine. Although plasmid-mediated conjugation is known to play a role in spreading antimicrobial resistance, its specific impact on resistance transmission within the broiler microbiota is still not well understood. We assessed conjugation dynamics of the mcr-1 gene from a pAmpC- E. coli to an ESBL- E. coli observed in an in vivo broiler chicken trial and compared them to conjugation frequencies under different in vitro conditions (LB broth, intestinal chicken cells in DMEM/F-12 medium, and DMEM/F-12 medium alone), with two initial bacterial loads.

resultsFrom in vivo trial, among 138 broiler chickens sampled after a 49-day fattening period, transconjugants were detected in the cecal content of 35 broilers. The median conjugation frequency observed was of -5.02 log

conclusionsWe confirmed bacterial conjugation between pAmpC-producing E. coli carrying the mcr-1 gene and ESBL-producing E. coli both in vitro and in vivo. The similar conjugation efficiencies observed across different in vitro methods suggest that experimental conditions have minimal influence under controlled settings. In contrast, the in vivo results underscore the significance of the host's physiological environment in HGT. The presence of transconjugants after a 49-day fattening period indicates that intestinal bacteria function as reservoirs for resistance plasmids and could facilitate their spread throughout the broiler production chain. However, limitations like the possibility of plasmid transfer to other bacteria, unknown persistence of the plasmid in the gut, and potential modulations of transfer efficiency under antibiotic selection must be considered when interpreting the results.

Indexed as

Bacterial Proteinsbeta-LactamasesChickensConjugation, GeneticEscherichia coliAnimalsAnti-Bacterial AgentsEscherichia coli InfectionsEscherichia coli ProteinsGene Transfer, HorizontalPlasmidsAmpC beta-lactamasesAnti-Bacterial AgentsBacterial Proteinsbeta-LactamasesEscherichia coli ProteinsMCR-1 protein, E coliAntimicrobial resistanceBroiler chickenConjugation frequencyESBLEscherichia colimcr-1pAmpCPlasmidTransconjugant

Identifiers

PMID41673559
PMCPMC13041292

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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.