title: Antibiotic stress selects against cooperation in the pathogenic bacterium Pseudomonas aeruginosa.
abstract: Cheats are a pervasive threat to public goods production in natural and human communities, as they benefit from the commons without contributing to it. Although ecological antagonisms such as predation, parasitism, competition, and abiotic environmental stress play key roles in shaping population biology, it is unknown how such stresses generally affect the ability of cheats to undermine cooperation. We used theory and experiments to address this question in the pathogenic bacterium, Pseudomonas aeruginosa Although public goods producers were selected against in all populations, our competition experiments showed that antibiotics significantly increased the advantage of nonproducers. Moreover, the dominance of nonproducers in mixed cultures was associated with higher resistance to antibiotics than in either monoculture. Mathematical modeling indicates that accentuated costs to producer phenotypes underlie the observed patterns. Mathematical analysis further shows how these patterns should generalize to other taxa with public goods behaviors. Our findings suggest that explaining the maintenance of cooperative public goods behaviors in certain natural systems will be more challenging than previously thought. Our results also have specific implications for the control of pathogenic bacteria using antibiotics and for understanding natural bacterial ecosystems, where subinhibitory concentrations of antimicrobials frequently occur.
authors.affiliation: Institut des Sciences de l'Evolution, CNRS-Université de Montpellier, Montpellier Cedex 5 34095, France; marie.vasse@gmail.com mhochber@univ-montp2.fr.
authors.forename: Marie
authors.initials: M
authors.lastname: Vasse
authors.affiliation: Institut des Sciences de l'Evolution, CNRS-Université de Montpellier, Montpellier Cedex 5 34095, France.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Noble
authors.affiliation: Institut des Sciences de l'Evolution, CNRS-Université de Montpellier, Montpellier Cedex 5 34095, France.|Institute of Statistical Science, Academia Sinica, Nankang 11529, Taipei, Taiwan.
authors.forename: Andrei R
authors.initials: AR
authors.lastname: Akhmetzhanov
authors.affiliation: Institut des Sciences de l'Evolution, CNRS-Université de Montpellier, Montpellier Cedex 5 34095, France.
authors.forename: Clara
authors.initials: C
authors.lastname: Torres-Barceló
authors.affiliation: Institut des Sciences de l'Evolution, CNRS-Université de Montpellier, Montpellier Cedex 5 34095, France.
authors.forename: James
authors.initials: J
authors.lastname: Gurney
authors.affiliation: Institut des Sciences de l'Evolution, CNRS-Université de Montpellier, Montpellier Cedex 5 34095, France.
authors.forename: Simon
authors.initials: S
authors.lastname: Benateau
authors.affiliation: Institut des Sciences de l'Evolution, CNRS-Université de Montpellier, Montpellier Cedex 5 34095, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Gougat-Barbera
authors.affiliation: Institut des Sciences de l'Evolution, CNRS-Université de Montpellier, Montpellier Cedex 5 34095, France.
authors.forename: Oliver
authors.initials: O
authors.lastname: Kaltz
authors.affiliation: Institut des Sciences de l'Evolution, CNRS-Université de Montpellier, Montpellier Cedex 5 34095, France; marie.vasse@gmail.com mhochber@univ-montp2.fr.|Santa Fe Institute, Santa Fe, NM 87501.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Hochberg
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D005075:Biological Evolution; D024881:Drug Resistance, Bacterial; D006801:Humans; D056265:Microbial Interactions / Q000187:drug effects* / Q000235:genetics / Q000502:physiology*; D008954:Models, Biological; D009842:Oligopeptides / Q000096:biosynthesis / Q000235:genetics; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000235:genetics / Q000502:physiology*; D017262:Siderophores / Q000096:biosynthesis / Q000235:genetics; D013312:Stress, Physiological
chemical_list: D000900:Anti-Bacterial Agents; D009842:Oligopeptides; D017262:Siderophores; C042453:pyoverdin
keywords: antibiotics; cooperation; evolution; resistance; social behavior