TY - JOUR
T1 - Imipenem-relebactam susceptibility testing of gram-negative bacilli by agar dilution, disk diffusion, and gradient strip methods compared with broth microdilution
AU - Hakvoort, Hanna
AU - Bovenkamp, Evelyn
AU - Greenwood-Quaintance, Kerryl E.
AU - Schmidt-Malan, Suzannah M.
AU - Mandrekar, Jay N.
AU - Schuetz, Audrey N.
AU - Patel, Robin
N1 - Funding Information:
We acknowledge Melissa J. Karau, Peggy C. Kohner, Nicolynn C. Cole, Scott A. Cunningham, and Matthew P. Murphy for technical advice. We thank the Mayo Clinic Clinical Bacteriology Lab, Donna J. Hata from the Mayo Clinic in Jacksonville, FL, James R. Johnson from the VA Medical Center in Minneapolis, MN, and Hennepin County Medical Center in Minneapolis, MN, Mary K. Hayden and Karen Lolans from Rush University Medical Center, and Paul C. Schreckenberger from Loyola, both in Chicago, IL, Patricia J. Simner from the Johns Hopkins University, George G. Zhanel and Daryl J. Hoban from the University of Manitoba, Partha Pratim De, Sanjay Ryan Menon, and Shawn Vasoo from Tan Tock Seng Hospital, and Koh Tse Hsien from Singapore General Hospital in Singapore for isolates included in this study. Research reported in this publication was supported by Merck & Co. R.P. reports grants from CD Diagnostics, BioFire, Curetis, Merck & Co., Contrafect, Hutchison Biofilm Medical Solutions, Accelerate Diagnostics, Allergan, EnBiotix, and The Medicines Company. R. Patel is or has been a consultant to Curetis, Specific Technologies, Selux Dx, GenMark Diagnostics, PathoQuest, and Qvella; monies are paid to Mayo Clinic. In addition, R.P. has a patent issued on Bordetella pertussis/parapertussis PCR, a patent on a device/method for sonication with royalties paid by Samsung to Mayo Clinic, and a patent issued on an antibiofilm substance. R.P. receives travel reimbursement and an editor's stipend from ASM and IDSA and honoraria from the NBME, Up-to-Date and the Infectious Diseases Board Review Course. No conflicts of interest, financial or otherwise, are declared by the other authors. H.H. and E.B. performed experiments, analyzed and interpreted results, and drafted the manuscript. J.N.M. performed a statistical analysis of the results. K.E.G.-Q., R.P., S.M.S.-M., and A.N.S. edited and revised the manuscript. R.P. conceived of and designed the research and approved the final version of the manuscript.
Funding Information:
We acknowledge Melissa J. Karau, Peggy C. Kohner, Nicolynn C. Cole, Scott A. Cunningham, and Matthew P. Murphy for technical advice. We thank the Mayo Clinic Clinical Bacteriology Lab, Donna J. Hata from the Mayo Clinic in Jacksonville, FL, James R. Johnson from the VA Medical Center in Minneapolis, MN, and Hennepin County Medical Center in Minneapolis, MN, Mary K. Hayden and Karen Lolans from Rush University Medical Center, and Paul C. Schreckenberger from Loyola, both in Chicago, IL, Patricia J. Simner from the Johns Hopkins University, George G. Zhanel and Daryl J. Hoban from the University of Manitoba, Partha Pratim De, Sanjay Ryan Menon, and Shawn Vasoo from Tan Tock Seng Hospital, and Koh Tse Hsien from Singapore General Hospital in Singapore for isolates included in this study. Research reported in this publication was supported by Merck & Co. R.P. reports grants from CD Diagnostics, BioFire, Curetis, Merck & Co., Contrafect, Hutchison Biofilm Medical Solutions, Accelerate Diagnostics, Allergan, EnBiotix, and The Medicines Company. R. Patel is or has been a consultant to Curetis, Specific Technologies, Selux Dx, GenMark Diagnostics, PathoQuest, and Qvella; monies are paid to Mayo Clinic. In addition, R.P. has a patent issued on Bordetella pertussis/parapertussis PCR, a patent on a device/method for sonication with royalties paid by Samsung to Mayo Clinic, and a patent issued on an antibiofilm substance. R.P. receives travel reimbursement and an editor’s stipend from ASM and IDSA and honoraria from the NBME, Up-to-Date and the Infectious Diseases Board Review Course. No conflicts of interest, financial or otherwise, are declared by the other authors. H.H. and E.B. performed experiments, analyzed and interpreted results, and drafted the manuscript. J.N.M. performed a statistical analysis of the results. K.E.G.-Q., R.P., S.M.S.-M., and A.N.S. edited and revised the manuscript. R.P. conceived of and designed the research and approved the final version of the manuscript.
Publisher Copyright:
Copyright © 2020 American Society for Microbiology. All Rights Reserved.
PY - 2020/10
Y1 - 2020/10
N2 - This study aimed to determine whether agar dilution, research-use-only disk diffusion (Mast Group Ltd., Bootle Merseyside, UK), Etest (bioMérieux, Inc., Durham, NC), and MIC test strip (MTS) (Liofilchem, Inc., Waltham, MA) methods yield equivalent results to those of broth microdilution (BMD) for imipenem-relebactam susceptibility testing using a collection of 297 Gram-negative bacilli, including members of the order Enterobacterales and Pseudomonas aeruginosa, enriched for drug resistance. MIC and disk diameter results were interpreted using United States Food and Drug Administration breakpoints. Overall, 76.8% of the isolates tested were susceptible to imipenem-relebactam by BMD. MIC values for agar dilution, Etest, and MTS were not significantly different from that for BMD, although they tended to be 1 to 2 dilutions higher. Essential agreement was 95.6% for agar dilution, 90.6% for Etest, and 85.2% for MTS. Categorical agreement was 98.0% for agar dilution, 73.1% for disk diffusion, 96.3% for Etest, and 96.6% for MTS. In conclusion, agar dilution and Etest yielded comparable results to BMD for imipenem-relebactam.
AB - This study aimed to determine whether agar dilution, research-use-only disk diffusion (Mast Group Ltd., Bootle Merseyside, UK), Etest (bioMérieux, Inc., Durham, NC), and MIC test strip (MTS) (Liofilchem, Inc., Waltham, MA) methods yield equivalent results to those of broth microdilution (BMD) for imipenem-relebactam susceptibility testing using a collection of 297 Gram-negative bacilli, including members of the order Enterobacterales and Pseudomonas aeruginosa, enriched for drug resistance. MIC and disk diameter results were interpreted using United States Food and Drug Administration breakpoints. Overall, 76.8% of the isolates tested were susceptible to imipenem-relebactam by BMD. MIC values for agar dilution, Etest, and MTS were not significantly different from that for BMD, although they tended to be 1 to 2 dilutions higher. Essential agreement was 95.6% for agar dilution, 90.6% for Etest, and 85.2% for MTS. Categorical agreement was 98.0% for agar dilution, 73.1% for disk diffusion, 96.3% for Etest, and 96.6% for MTS. In conclusion, agar dilution and Etest yielded comparable results to BMD for imipenem-relebactam.
KW - Agar dilution
KW - Broth microdilution
KW - Disk diffusion
KW - Gradient strips
KW - Imipenem-relebactam
KW - Susceptibility testing
UR - http://www.scopus.com/inward/record.url?scp=85091565067&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85091565067&partnerID=8YFLogxK
U2 - 10.1128/JCM.00695-20
DO - 10.1128/JCM.00695-20
M3 - Article
C2 - 32727832
AN - SCOPUS:85091565067
VL - 58
JO - Journal of Clinical Microbiology
JF - Journal of Clinical Microbiology
SN - 0095-1137
IS - 10
M1 - e0069520
ER -