Antibiotic combination efficacy (ACE) networks for a Pseudomonas aeruginosa model

PLoS Biol. 2018 Apr 30;16(4):e2004356. doi: 10.1371/journal.pbio.2004356. eCollection 2018 Apr.

Abstract

The spread of antibiotic resistance is always a consequence of evolutionary processes. The consideration of evolution is thus key to the development of sustainable therapy. Two main factors were recently proposed to enhance long-term effectiveness of drug combinations: evolved collateral sensitivities between the drugs in a pair and antagonistic drug interactions. We systematically assessed these factors by performing over 1,600 evolution experiments with the opportunistic nosocomial pathogen Pseudomonas aeruginosa in single- and multidrug environments. Based on the growth dynamics during these experiments, we reconstructed antibiotic combination efficacy (ACE) networks as a new tool for characterizing the ability of the tested drug combinations to constrain bacterial survival as well as drug resistance evolution across time. Subsequent statistical analysis of the influence of the factors on ACE network characteristics revealed that (i) synergistic drug interactions increased the likelihood of bacterial population extinction-irrespective of whether combinations were compared at the same level of inhibition or not-while (ii) the potential for evolved collateral sensitivities between 2 drugs accounted for a reduction in bacterial adaptation rates. In sum, our systematic experimental analysis allowed us to pinpoint 2 complementary determinants of combination efficacy and to identify specific drug pairs with high ACE scores. Our findings can guide attempts to further improve the sustainability of antibiotic therapy by simultaneously reducing pathogen load and resistance evolution.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Physiological*
  • Anti-Bacterial Agents / pharmacology*
  • Bayes Theorem
  • Biological Evolution
  • Drug Antagonism
  • Drug Resistance, Multiple, Bacterial / drug effects*
  • Drug Synergism
  • Microbial Sensitivity Tests
  • Microbial Viability / drug effects
  • Pseudomonas aeruginosa / drug effects*
  • Pseudomonas aeruginosa / growth & development

Substances

  • Anti-Bacterial Agents

Grants and funding

Deutsche Forschungsgemeinschaft (grant number SCHU 1415/12-1). Individual research grant to HS and GJ. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. International Max-Planck Research School for Evolutionary Biology. Stipend to CB. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Deutsche Forschungsgemeinschaft (grant number EXC 306). Excellence Cluster Inflammation at Interfaces; infrastructural funding to HS. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Max-Planck Society. Max-Planck Fellowship to HS. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.