title: Antibiotic efficacy is linked to bacterial cellular respiration.
abstract: Bacteriostatic and bactericidal antibiotic treatments result in two fundamentally different phenotypic outcomes--the inhibition of bacterial growth or, alternatively, cell death. Most antibiotics inhibit processes that are major consumers of cellular energy output, suggesting that antibiotic treatment may have important downstream consequences on bacterial metabolism. We hypothesized that the specific metabolic effects of bacteriostatic and bactericidal antibiotics contribute to their overall efficacy. We leveraged the opposing phenotypes of bacteriostatic and bactericidal drugs in combination to investigate their activity. Growth inhibition from bacteriostatic antibiotics was associated with suppressed cellular respiration whereas cell death from most bactericidal antibiotics was associated with accelerated respiration. In combination, suppression of cellular respiration by the bacteriostatic antibiotic was the dominant effect, blocking bactericidal killing. Global metabolic profiling of bacteriostatic antibiotic treatment revealed that accumulation of metabolites involved in specific drug target activity was linked to the buildup of energy metabolites that feed the electron transport chain. Inhibition of cellular respiration by knockout of the cytochrome oxidases was sufficient to attenuate bactericidal lethality whereas acceleration of basal respiration by genetically uncoupling ATP synthesis from electron transport resulted in potentiation of the killing effect of bactericidal antibiotics. This work identifies a link between antibiotic-induced cellular respiration and bactericidal lethality and demonstrates that bactericidal activity can be arrested by attenuated respiration and potentiated by accelerated respiration. Our data collectively show that antibiotics perturb the metabolic state of bacteria and that the metabolic state of bacteria impacts antibiotic efficacy.
authors.affiliation: Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115; Institute for Medical Engineering & Science, Department of Biological Engineering, and Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA 02139; Broad Institute of MIT and Harvard, Cambridge, MA 02139; Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA 02114; Harvard Medical School, Boston, MA 02115; jimjc@mit.edu mlobritz@mgh.harvard.edu akhalil@bu.edu.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Lobritz
authors.affiliation: Department of Molecular Microbiology and Immunology, Brown University, Providence, RI 02912;
authors.forename: Peter
authors.initials: P
authors.lastname: Belenky
authors.affiliation: Institute for Medical Engineering & Science, Department of Biological Engineering, and Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA 02139; Broad Institute of MIT and Harvard, Cambridge, MA 02139;
authors.forename: Caroline B M
authors.initials: CB
authors.lastname: Porter
authors.affiliation: Institute for Medical Engineering & Science, Department of Biological Engineering, and Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA 02139; Broad Institute of MIT and Harvard, Cambridge, MA 02139;
authors.forename: Arnaud
authors.initials: A
authors.lastname: Gutierrez
authors.affiliation: Institute for Medical Engineering & Science, Department of Biological Engineering, and Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA 02139; Broad Institute of MIT and Harvard, Cambridge, MA 02139;
authors.forename: Jason H
authors.initials: JH
authors.lastname: Yang
authors.affiliation: Department of Biomedical Engineering and Biological Design Center, Boston University, Boston, MA 02215;
authors.forename: Eric G
authors.initials: EG
authors.lastname: Schwarz
authors.affiliation: Department of Cell Biology and Molecular Genetics, Institute for Physical Science and Technology, Department of Biomedical Engineering, and Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742;
authors.forename: Daniel J
authors.identifier: http://orcid.org/0000-0002-0751-1116
authors.initials: DJ
authors.lastname: Dwyer
authors.affiliation: Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115; Department of Biomedical Engineering and Biological Design Center, Boston University, Boston, MA 02215; jimjc@mit.edu mlobritz@mgh.harvard.edu akhalil@bu.edu.
authors.forename: Ahmad S
authors.initials: AS
authors.lastname: Khalil
authors.affiliation: Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115; Institute for Medical Engineering & Science, Department of Biological Engineering, and Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA 02139; Broad Institute of MIT and Harvard, Cambridge, MA 02139; Harvard-MIT Program in Health Sciences and Technology, Cambridge, MA 02139 jimjc@mit.edu mlobritz@mgh.harvard.edu akhalil@bu.edu.
authors.forename: James J
authors.initials: JJ
authors.lastname: Collins
mesh_terms: D000255:Adenosine Triphosphate / Q000096:biosynthesis; D000900:Anti-Bacterial Agents / Q000145:classification / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D018407:Bacterial Physiological Phenomena / Q000187:drug effects; D004347:Drug Interactions; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D055442:Metabolome / Q000187:drug effects; D055432:Metabolomics / Q000379:methods; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects*; D009154:Mutation; D010101:Oxygen Consumption / Q000187:drug effects*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D000255:Adenosine Triphosphate
keywords: E. coli; S. aureus; antibiotics; cellular respiration; metabolomics