TY - JOUR
T1 - Mechanism of high-level daptomycin resistance in Corynebacterium striatum
AU - Goldner, Nicholas K.
AU - Bulow, Christopher
AU - Cho, Kevin
AU - Wallace, Meghan
AU - Hsu, Fong Fu
AU - Patti, Gary J.
AU - Burnham, Carey Ann
AU - Schlesinger, Paul
AU - Dantasa, Gautam
N1 - Funding Information:
We thank Wandy Beatty and the Molecular Microbiology Imaging Facility for assistance with transmission electron microscopy of C. striatum samples. We thank Pratim Biswas and the Jens Molecular and Nanoscale Analysis Laboratory for assistance in assaying bacterial membrane charges via Zetasizing. We thank members of the Dantas laboratory for insightful discussions of the results and conclusions. We thank Richa Rathore for insights and assistance in editing content for clarity and flow. We thank Audrey Dang for insights and assistance in designing graphical representations of this data. This work was supported in part by awards to G.D. through the Edward Mallinckrodt, Jr. Foundation (Scholar Award) and by awards from the National Institute of General Medical Sciences, the National Institute of Allergy and Infectious Diseases, and the Eunice Kennedy Shriver National Institute of Child Health & Human Development of the National Institutes of Health (NIH) under award numbers R01GM099538, R01AI123394, and R01HD092414, respectively. C.B. received support from an NHGRI training grant through award number T32 HG000045 to Michael Brent and Barak Cohen. Mass spectrometric analysis was performed in the Washington University Mass Spectrometry Resource, which is supported by National Institutes of Health grants P41GM103422, P30DK020579, and P30DK056341, and with the assistance of the Patti Lab (R35ES028365). The content does not necessarily represent the official views of the funding agencies.
Funding Information:
This work was supported in part by awards to G.D. through the Edward Mallinckrodt, Jr. Foundation (Scholar Award) and by awards from the National Institute of General Medical Sciences, the National Institute of Allergy and Infectious Diseases, and the Eunice Kennedy Shriver National Institute of Child Health & Human Development of the National Institutes of Health (NIH) under award numbers R01GM099538, R01AI123394, and R01HD092414, respectively. C.B. received support from an NHGRI training grant through award number T32 HG000045 to Michael Brent and Barak Cohen. Mass spectrometric analysis was performed in the Washington University Mass Spectrometry Resource, which is supported by National Institutes of Health grants P41GM103422, P30DK020579, and P30DK056341, and with the assistance of the Patti Lab (R35ES028365). The content does not necessarily represent the official views of the funding agencies.
Publisher Copyright:
© 2018 Goldner et al.
PY - 2018/7/1
Y1 - 2018/7/1
N2 - Daptomycin, a last-line-of-defense antibiotic for treating Gram-positive infections, is experiencing clinical failure against important infectious agents, including Corynebacterium striatum. The recent transition of daptomycin to generic status is projected to dramatically increase availability, use, and clinical failure. Here we confirm the genetic mechanism of high-level daptomycin resistance (HLDR; MIC = >256 μg/ml) in C. striatum, which evolved within a patient during daptomycin therapy, a phenotype recapitulated in vitro. In all 8 independent cases tested, loss-offunction mutations in phosphatidylglycerol synthase (pgsA2) were necessary and sufficient for high-level daptomycin resistance. Through lipidomic and biochemical analysis, we demonstrate that daptomycin's activity is dependent on the membrane phosphatidylglycerol (PG) concentration. Until now, the verification of PG as the in vivo target of daptomycin has proven difficult since tested cell model systems were not viable without membrane PG. C. striatum becomes daptomycin resistant at a high level by removing PG from the membrane and changing the membrane composition to maintain viability. This work demonstrates that loss-of-function mutation in pgsA2 and the loss of membrane PG are necessary and sufficient to produce highlevel resistance to daptomycin in C. striatum. IMPORTANCE Antimicrobial resistance threatens the efficacy of antimicrobial treatment options, including last-line-of-defense drugs. Understanding how this resistance develops can help direct antimicrobial stewardship efforts and is critical to designing the next generation of antimicrobial therapies. Here we determine how Corynebacterium striatum, a skin commensal and opportunistic pathogen, evolved high-level resistance to a drug of last resort, daptomycin. Through a single mutation, this pathogen was able to remove the daptomycin's target, phosphatidylglycerol (PG), from the membrane and evade daptomycin's bactericidal activity. We found that additional compensatory changes were not necessary to support the removal of PG and replacement with phosphatidylinositol (PI). The ease with which C. striatum evolved high-level resistance is cause for alarm and highlights the importance of screening new antimicrobials against a wide range of clinical pathogens which may harbor unique capacities for resistance evolution.
AB - Daptomycin, a last-line-of-defense antibiotic for treating Gram-positive infections, is experiencing clinical failure against important infectious agents, including Corynebacterium striatum. The recent transition of daptomycin to generic status is projected to dramatically increase availability, use, and clinical failure. Here we confirm the genetic mechanism of high-level daptomycin resistance (HLDR; MIC = >256 μg/ml) in C. striatum, which evolved within a patient during daptomycin therapy, a phenotype recapitulated in vitro. In all 8 independent cases tested, loss-offunction mutations in phosphatidylglycerol synthase (pgsA2) were necessary and sufficient for high-level daptomycin resistance. Through lipidomic and biochemical analysis, we demonstrate that daptomycin's activity is dependent on the membrane phosphatidylglycerol (PG) concentration. Until now, the verification of PG as the in vivo target of daptomycin has proven difficult since tested cell model systems were not viable without membrane PG. C. striatum becomes daptomycin resistant at a high level by removing PG from the membrane and changing the membrane composition to maintain viability. This work demonstrates that loss-of-function mutation in pgsA2 and the loss of membrane PG are necessary and sufficient to produce highlevel resistance to daptomycin in C. striatum. IMPORTANCE Antimicrobial resistance threatens the efficacy of antimicrobial treatment options, including last-line-of-defense drugs. Understanding how this resistance develops can help direct antimicrobial stewardship efforts and is critical to designing the next generation of antimicrobial therapies. Here we determine how Corynebacterium striatum, a skin commensal and opportunistic pathogen, evolved high-level resistance to a drug of last resort, daptomycin. Through a single mutation, this pathogen was able to remove the daptomycin's target, phosphatidylglycerol (PG), from the membrane and evade daptomycin's bactericidal activity. We found that additional compensatory changes were not necessary to support the removal of PG and replacement with phosphatidylinositol (PI). The ease with which C. striatum evolved high-level resistance is cause for alarm and highlights the importance of screening new antimicrobials against a wide range of clinical pathogens which may harbor unique capacities for resistance evolution.
KW - Antimicrobial resistance
KW - Artificial liposomes
KW - Corynebacterium
KW - Daptomycin
KW - Genomics
KW - Lipidomics
KW - Phosphatidylglycerol
KW - Surface plasmon resonance
KW - Transcriptomics
UR - http://www.scopus.com/inward/record.url?scp=85056732591&partnerID=8YFLogxK
U2 - 10.1128/MSPHEREDIRECT.00371-18
DO - 10.1128/MSPHEREDIRECT.00371-18
M3 - Article
C2 - 30089649
AN - SCOPUS:85056732591
SN - 2379-5042
VL - 3
JO - mSphere
JF - mSphere
IS - 4
M1 - 37118
ER -