Pneumococcal competition modulates antibiotic resistance in the pre-vaccination era: A modelling study

José Lourenço*, Yair Daon, Andrea Gori, Uri Obolski*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


The ongoing emergence of antibiotic resistant strains and high frequencies of antibiotic resistance of Streptococcus pneumoniae poses a major public health challenge. How and which ecological and evolutionary mechanisms maintain the coexistence of antibiotic resistant and susceptible strains remains largely an open question. We developed an individual-based, stochastic model expanding on a previous pneumococci modelling framework. We explore how between-and within-host mechanisms of competition can sustain observed levels of resistance to antibiotics in the pre-vaccination era. Our framework considers that within-host competition for co-colonization between resistant and susceptible strains can arise via pre-existing immunity (immunological competition) or intrinsic fitness differences due to resistance costs (ecological competition). We find that beyond stochastic-ity, population structure or movement, competition at the within-host level can explain observed resistance frequencies. We compare our simulation results to pneumococcal antibiotic resistance data in the European region using approximate Bayesian computation. Our results demonstrate that ecological competition for co-colonization can explain the variation in co-existence of resistant and susceptible pneumococci observed in the pre-vaccination era. Furthermore, we show that within-host pneumococcal competition can facilitate the maintenance of resistance in the pre-vaccination era. Accounting for these competition-related components of pneumococcal dynamics can improve our understanding of drivers for the emergence and maintenance of antibiotic resistance in pneumococci.

Original languageEnglish
Article number265
Issue number3
StatePublished - Mar 2021


  • Antibiotic resistance
  • Ecological competition
  • Immunological competition
  • Pre-vaccination
  • Streptococcus pneumoniae


Dive into the research topics of 'Pneumococcal competition modulates antibiotic resistance in the pre-vaccination era: A modelling study'. Together they form a unique fingerprint.

Cite this