The effects of ecological interactions and distinct conjugation rates on the invasion of a conjugative plasmid in bacterial communities

TY - JOUR

T1 - The effects of ecological interactions and distinct conjugation rates on the invasion of a conjugative plasmid in bacterial communities

AU - Alderliesten, Jesse B.

AU - Zwart, Mark P.

AU - de Visser, J. Arjan G.M.

AU - Stegeman, Arjan

AU - Fischer, Egil A.J.

N1 - Publisher Copyright: © 2025

PY - 2026/2

Y1 - 2026/2

N2 - Mathematical models that are used to study the persistence and spread of antibiotic resistance plasmids usually describe conjugation within a single bacterial species or neglect ecological interactions and differences in conjugation rates between species. To increase our understanding of the role of differences between species in plasmid dynamics in a bacterial community, we extend the generalised Lotka-Volterra model with plasmid-bearing populations and density-dependent conjugation. With this model, we investigate how ecological interactions between species with distinct conjugation rates affect the invasion and spread of a conjugative plasmid in a bacterial community. We find that the possibility for plasmid invasion mediated by a species that was already present in the modelled plasmid-free communities is mainly determined by the intraspecies conjugation rate of the initially plasmid-bearing species and the fitness costs of bearing a plasmid. In contrast, the possibility for plasmid invasion mediated by a species that was not yet present in the plasmid-free community is mainly determined by ecological interspecies interactions involving the initially plasmid-bearing species. Nevertheless, decreased interspecies conjugation rates to and from the initially plasmid-bearing species reduce the spread of a plasmid through the community. In both scenarios, weaker competitive and stronger mutualistic ecological interspecies interactions reduce the spread of a plasmid through the community, limiting the creation of new plasmid-host combinations. Our results indicate that ecological interactions and differences in conjugation rates between species should be taken into account when modelling the invasion and spread of plasmids.

AB - Mathematical models that are used to study the persistence and spread of antibiotic resistance plasmids usually describe conjugation within a single bacterial species or neglect ecological interactions and differences in conjugation rates between species. To increase our understanding of the role of differences between species in plasmid dynamics in a bacterial community, we extend the generalised Lotka-Volterra model with plasmid-bearing populations and density-dependent conjugation. With this model, we investigate how ecological interactions between species with distinct conjugation rates affect the invasion and spread of a conjugative plasmid in a bacterial community. We find that the possibility for plasmid invasion mediated by a species that was already present in the modelled plasmid-free communities is mainly determined by the intraspecies conjugation rate of the initially plasmid-bearing species and the fitness costs of bearing a plasmid. In contrast, the possibility for plasmid invasion mediated by a species that was not yet present in the plasmid-free community is mainly determined by ecological interspecies interactions involving the initially plasmid-bearing species. Nevertheless, decreased interspecies conjugation rates to and from the initially plasmid-bearing species reduce the spread of a plasmid through the community. In both scenarios, weaker competitive and stronger mutualistic ecological interspecies interactions reduce the spread of a plasmid through the community, limiting the creation of new plasmid-host combinations. Our results indicate that ecological interactions and differences in conjugation rates between species should be taken into account when modelling the invasion and spread of plasmids.

KW - Horizontal gene transfer

KW - Microbial species interactions

KW - Multispecies model

KW - Plasmid dynamics

U2 - 10.1016/j.ecolmodel.2025.111418

DO - 10.1016/j.ecolmodel.2025.111418

M3 - Article

AN - SCOPUS:105022256084

SN - 0304-3800

VL - 512

JO - Ecological Modelling

JF - Ecological Modelling

M1 - 111418

ER -