A1 Journal article (refereed)
Genomic evolution of bacterial populations under co-selection by antibiotics and phage (2017)

Cairns, J., Frickel, J., Jalasvuori, M., Hiltunen, T., & Becks, L. (2017). Genomic evolution of bacterial populations under co-selection by antibiotics and phage. Molecular Ecology, 26 (7), 1848-1859. doi:10.1111/mec.13950

JYU authors or editors

Publication details

All authors or editors: Cairns, Johannes; Frickel, Jens; Jalasvuori, Matti; Hiltunen, Teppo; Becks, Lutz

Journal or series: Molecular Ecology

ISSN: 0962-1083

eISSN: 1365-294X

Publication year: 2017

Volume: 26

Issue number: 7

Pages range: 1848-1859

Publisher: Wiley-Blackwell Publishing Ltd.

Publication country: United Kingdom

Publication language: English

DOI: https://doi.org/10.1111/mec.13950

Research data link: http://dx.doi.org/10.5061/dryad.62s22

Open Access: Publication channel is not openly available

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/53814

Additional information: Special Issue: Microbial Local Adaptation

Abstract

Bacteria live in dynamic systems where selection pressures can alter rapidly, forcing adaptation to the prevailing conditions. In particular, bacteriophages and antibiotics of anthropogenic origin are major bacterial stressors in many environments. We previously observed that populations of the bacterium Pseudomonas fluorescens SBW25 exposed to the lytic bacteriophage SBW25Φ2 and a noninhibitive concentration of the antibiotic streptomycin (coselection) achieved higher levels of phage resistance compared to populations exposed to the phage alone. In addition, the phage became extinct under coselection while remaining present in the phage alone environment. Further, phenotypic tests indicated that these observations might be associated with increased mutation rate under coselection. In this study, we examined the genetic causes behind these phenotypes by whole‐genome sequencing clones isolated from the end of the experiments. We were able to identify genetic factors likely responsible for streptomycin resistance, phage resistance and hypermutable (mutator) phenotypes. This constitutes genomic evidence in support of the observation that while the presence of phage did not affect antibiotic resistance, the presence of antibiotic affected phage resistance. We had previously hypothesized an association between mutators and elevated levels of phage resistance under coselection. However, our evidence regarding the mechanism was inconclusive, as although with phage mutators were only found under coselection, additional genomic evidence was lacking and phage resistance was also observed in nonmutators under coselection. More generally, our study provides novel insights into evolution between univariate and multivariate selection (here two stressors), as well as the potential role of hypermutability in natural communities.

Keywords: antibiotic resistance

Free keywords: experimental evolution; sublethal antibiotic concentrations; phage resistance; Pseudomonas fluorescens; phage phi-2

Contributing organizations

Ministry reporting: Yes

Reporting Year: 2017

JUFO rating: 2