Rapid antimicrobial susceptibility test for identification of new therapeutics and drug combinations against multidrug-resistant bacteria.
Current antimicrobial susceptibility testing has limited screening capability for identifying empirical antibiotic combinations to treat severe bacterial infections with multidrug-resistant (MDR) organisms. We developed a new antimicrobial susceptibility assay using automated ultra-high-throughput screen technology in combination with a simple bacterial growth assay. A rapid screening of 5170 approved drugs and other compounds identified 25 compounds with activities against MDR Klebsiella pneumoniae. To further improve the efficacy and reduce the effective drug concentrations, we applied a targeted drug combination approach that integrates drugs' clinical antimicrobial susceptibility breakpoints, achievable plasma concentrations, clinical toxicities and mechanisms of action to identify optimal drug combinations. Three sets of three-drug combinations were identified with broad-spectrum activities against 10 MDR clinical isolates including K. pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Citrobacter freundii, Enterobacter cloacae and Escherichia coli. Colistin-auranofin-ceftazidime and colistin-auranofin-rifabutin suppressed >80% growth of all 10 MDR strains; while rifabutin-colistin-imipenem inhibited >75% of these strains except two Acinetobacter baumannii isolates. The results demonstrate this new assay has potential as a real-time method to identify new drugs and effective drug combinations to combat severe clinical infections with MDR organisms.
National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD 20892, USA.
Wei
W
Sun
Department of Laboratory Medicine, National Institutes of Health Clinical Center, Bethesda, MD 20892, USA.
Rebecca A
RA
Weingarten
National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD 20892, USA.
Miao
M
Xu
National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD 20892, USA.
Noel
N
Southall
National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD 20892, USA.
Sheng
S
Dai
National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD 20892, USA.
Paul
P
Shinn
National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD 20892, USA.
Philip E
PE
Sanderson
Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Peter R
PR
Williamson
Department of Laboratory Medicine, National Institutes of Health Clinical Center, Bethesda, MD 20892, USA.
Karen M
KM
Frank
National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD 20892, USA.
Wei
W
Zheng
D000151:Acinetobacter Infections / Q000382:microbiology; D040981:Acinetobacter baumannii / Q000187:drug effects / Q000254:growth & development / Q000302:isolation & purification; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018501:Antirheumatic Agents / Q000494:pharmacology*; D001310:Auranofin / Q000494:pharmacology*; D001424:Bacterial Infections / Q000382:microbiology; D003091:Colistin / Q000494:pharmacology*; D004338:Drug Combinations; D055808:Drug Discovery / Q000379:methods*; D024901:Drug Resistance, Multiple, Bacterial; D004357:Drug Synergism; D006801:Humans; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000254:growth & development / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000254:growth & development / Q000302:isolation & purification
D000900:Anti-Bacterial Agents; D018501:Antirheumatic Agents; D004338:Drug Combinations; D001310:Auranofin; D003091:Colistin