Epidemiological dynamics of bacteriocin competition and antibiotic resistance

Abstract

AbstractBacteriocins, toxic peptides involved in bacterial fratricide, are extremely diverse. Understanding the mechanisms that maintain this diversity is an important aim in bacterial ecology. Previous work on bacteriocin diversity has focused on dynamics, particularly ‘rock-paper-scissors’ dynamics, at the within-host scale. Yet, in species such as Streptococcus pneumoniae, with relatively short periods of colonisation and limited within-host diversity, processes at the epidemiological scale also shape eco-evolutionary dynamics. Here, we investigate bacteriocin dynamics in epidemiological models. We find that in these models, bacteriocin diversity arises more readily than in within-host models, and with more possible combinations of coexisting bacteriocin profiles. We also investigate a potential link between bacteriocin diversity and diversity at antibiotic resistance loci. Previous work has proposed that bacterial duration of carriage modulates the fitness of antibiotic resistance. We predict bacteriocins modulate duration of carriage, making them a plausible candidate for involvement in resistance dynamics.