Evidence of ESBL plasmid transfer and selective persistence of multiple host-associated Escherichia coli isolates in a chicken cecal fermentation model
Investigación publicada en Applied and Environmental Microbiology
19 de septiembre de 2025
The guts of animals and humans harbor diverse microbial communities that are regularly exposed to bacteria originating from food, water, and their surroundings. Species such as Escherichia coli are adept at colonizing multiple hosts, along with surviving in the environment. By encoding pathogenic traits and transmissible forms of antimicrobial resistance (AMR), E. coli can also pose a zoonotic risk. Our understanding of the factors that govern host residency is limited. Here, we used a chicken cecal fermentation model to study survival and the AMR transfer potential of 17 host-associated extended-spectrum ?-lactamase (ESBL)-producing E. coli isolates. Vessels containing chicken cecal contents were stabilized for 4 days before the addition of a cocktail comprising ESBL-producing E. coli obtained from human, cattle, pig, and chicken hosts. Consecutive sampling showed that pig and cattle-associated isolates persisted in most vessels, although the recovery of all isolates declined over time. Increasing the inoculum dose or adding ceftiofur helped to stabilize populations of ESBL E. coli within the vessels, although this did not result in outgrowth of resistant populations in all vessels. Sequencing revealed that most new ESBL-producing E. coli recovered during the study acquired a blaCTX-M-1 plasmid from a single ESBL E. coli included in the cocktail that lacked host-specific traits (generalist). Our data highlight that isolate-specific differences in the E. coli genome composition likely explain the persistence of specific clones and efficiency of plasmid transfer, both of which could impact the spread of AMR in complex communities.IMPORTANCEThere are few insights into how host-associated Escherichia coli behave within the gut environment of other hosts. E. coli isolates that are immigrants to the gastrointestinal system of humans and animals have the potential to transfer their resistance to other native bacteria. A better understanding of this process is needed to assess how the gastrointestinal environment could serve as a reservoir and a melting pot of new, multidrug-resistant E. coli isolates
Leng J., Ferrandis-Vila M., Oldenkamp R., Mehat JW., Fivian-Hughes A., Kumar-Tiwari S., Van der Putten B., Trung-Nguyen V., Bethe A., Clark J., Singh P., Semmler T., Schwarz S., Alvarez J., Hoa NT., Bootsma M., Menge C., Berens C., Schultsz C., Ritchie JM. y La Ragione R.
 | School of Veterinary Medicine. Faculty of Health and Medical Sciences. University of Surrey. |
 | University of Liverpool. |
 | Institute of Molecular Pathogenesis. Friedrich Loeffler Institut-Bundesforschungsinstitut fuer Tiergesundheit (FLI). |
 | Amsterdam Institute for Life and Environment (A-LIFE). Faculty of Science. University of Amsterdam. |
| Department of Global Health-Amsterdam-Institute for Global Health and Development. Academic Medical Center. University of Amsterdam. |
| School Biosciences and Medicine. Faculty of Health and Medical Sciences. University of Surrey. |
 | Genome sequencing and genomic epidemiology. Robert Koch Institute (RKI). |
| Gut Microbes and Health Institute Strategic Program. Quadram Institute Bioscience. Norwich Research Park. | |
 | Amsterdam Umc. |
| Oxford University Clinical Research Unit Vietnam. | |
| Institute of Microbiology and Epizootics. Veterinary Centre for Resistance Research (TZR). School of Veterinary Medicine. Freie Universität Berlin. | |
| Department of Environmental Hygiene. German Environment Agency. | |
| Epsom and St Helier University Hospitals NHS Trust. | |
| Watford General Hospital. | |
 | Centro de Vigilancia Sanitaria Veterinaria (VISAVET). Universidad Complutense (UCM). |
| Departamento de Sanidad Animal. Facultad de Veterinaria. Universidad Complutense (UCM). |
 | Centre for Tropical Medicine and Global Health. Nuffield Department of Medicine. University of Oxford. |
| Microbiology Department and the Micro-Parasitology Unit of the Center for Bio-Medical Research. Pham Ngoc Thach University of Medicine. | |
