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Principal Investigator: Thea Brennan-Krohn
Organization: BETH ISRAEL DEACONESS MEDICAL CENTER
Fiscal Year: 2024
Award: $466,211
Funding agency: National Institute of Allergy and Infectious Diseases
Project Summary/Abstract
Antibiotics in the b-lactam/b-lactamase inhibitor (BLBLI) class are among the mainstays of antimicrobial
treatment for gram-negative bacteria such as E. coli and Pseudomonas aeruginosa. Until recently, all b-
lactamase inhibitors in these combinations were themselves b-lactam compounds that lacked direct antimicrobial
activity. However, bacteria are increasingly developing resistance to all currently available BLBLIs. To address
this problem, new combinations are being developed that incorporate novel diazabicyclooctane (DBO) b-
lactamase inhibitors, which are non-b-lactam compounds that possess intrinsic direct antimicrobial activity
mediated by binding to penicillin-binding protein 2 (PBP2). While the expanded spectrum of these new
combinations is promising, the highly multidrug-resistant bacteria they will be used to treat are prone to the
development of additional resistance mechanisms, and PBP2-mediated antibacterial activity in particular is
known to be vulnerable to the emergence of resistance during treatment. The overall goal of this project is to
characterize the development of resistance to novel DBO-containing BLBLIs in order to discover how best to
make use of them while preventing the emergence of resistance. In Aim #1, rates of resistance to DBO-
containing BLBLIs will be assessed among a large, diverse collection of gram-negative bacterial strains including
E. coli, Klebsiella pneumoniae, Enterobacter cloacae complex, and P. aeruginosa. In Aim #2, mechanisms of
resistance to these agents will be investigated using two different ‘omics approaches. First, whole genome
sequencing will be used to identify mutations in strains in which resistance has developed. Second, gene
expression profiling using RNA-Seq will be employed to investigate the transcriptomic response of both
susceptible and resistant bacteria to DBO-containing BLBLI treatment. The goal of Aim #3 is to understand how
to prevent resistance to DBO-containing BLBLIs in models that better simulate in vivo treatment conditions. A
time-kill assay, a hollow-fiber infection model, which allows for simulation of changing antibiotic concentrations
over time, and a mouse thigh infection model will be employed to identify combinations that prevent resistance
over longer periods of drug exposure, and whole genome sequencing of resistant isolates will be used to
compare resistance-conferring mutations that occur in these models to those observed in standard in vitro
assays. The proposed project, when completed, will provide a guide to the most effective ways to utilize novel
DBO-containing BLBLIs in order to effectively treat patients with MDR infections while preventing the emergence
of resistance.
Terms: <Address><Affinity><Anti-Bacterial Agents><Antibiotic Agents><Antibiotic Drugs><Antibiotics><Assay><Bacteria><Bacteria resistance><Bacteria resistant><Bacterial resistant><Base Pairing><Binding><Bioassay><Biological Assay><Ccra beta-lactamase><Ceftazidime><Clinical><Clinical Research><Clinical Study><Clinical Trials><Collection><Complex><Data><Development><Drug Exposure><Drug resistance><Drugs><E cloacae><E coli><E. cloacae><E. coli><Enhancers><Enterobacter cloacae><Escherichia coli><Exhibits><Exposure to><Extended-spectrum beta-lactamase><Extended-spectrum β-lactamase><Fiber><Frequencies><Future><G24 protein><Gene Expression Monitoring><Gene Expression Pattern Analysis><Gene Expression Profiling><Generalized Growth><Genetic Alteration><Genetic Change><Genetic defect><Genomics><Goals><Gram-Negative Bacteria><Growth><Infection><K pneumoniae><K. pneumoniae><Klebsiella pneumoniae><Knowledge><L-Serine><Lactam Antibiotics><Lactamase><Lactams><Mediating><Medication><Methods><Methylation><Mice><Mice Mammals><Miscellaneous Antibiotic><Modeling><Molecular Interaction><Monobactam Antibiotics><Monobactams><Monocyclic beta-Lactams><Multi-Drug Resistance><Multidrug Resistance><Multiple Anti-bacterial Drug Resistance><Multiple Anti-bacterial Drug Resistant><Multiple Bacterial Drug Resistance><Multiple Drug Resistance><Multiple Drug Resistant><Murine><Mus><Mutation><Organism><P aeruginosa><P. aeruginosa><Patients><Penicillin Binding Protein 2><Pharmaceutical Preparations><Predisposition><Pseudomonas aeruginosa><Pseudomonas pyocyanea><R-Series Research Projects><R01 Mechanism><R01 Program><RNA Seq><RNA sequencing><RNAseq><Regimen><Research Grants><Research Project Grants><Research Projects><Resistance><Resistance development><Resistance to Multi-drug><Resistance to Multidrug><Resistance to Multiple Anti-bacterial Drug><Resistance to Multiple Drug><Resistant development><Resistant to Multiple Anti-bacterial Drug><Resistant to Multiple Drug><Resistant to multi-drug><Resistant to multidrug><Risk><Role><Safety><Serine><Susceptibility><Testing><Thigh><Thigh structure><Time><Tissue Growth><Transcript Expression Analyses><Transcript Expression Analysis><Work><analyze gene expression><anti-bacterial><anti-microbial><antimicrobial><bacterial resistance><beta lactam antibiotic><beta lactam hydrolase><beta-Lactamase><beta-Lactamhydrolase><beta-Lactams><carbapenemase><clinical development><developing resistance><developmental><drug resistant><drug/agent><entire genome><full genome><gene expression analysis><gene expression assay><genome mutation><genome sequencing><in vitro Assay><in vivo><inhibitor><inhibitor drug><inhibitor therapeutic><inhibitor therapy><living system><multi-drug resistant><multi-drug resistant bacteria><multidrug resistant><multidrug resistant bacteria><new drug treatments><new drugs><new pharmacological therapeutic><new therapeutics><new therapy><next generation therapeutics><novel><novel drug treatments><novel drugs><novel pharmaco-therapeutic><novel pharmacological therapeutic><novel therapeutics><novel therapy><ontogeny><pathogen><pre-clinical study><preclinical study><preservation><prevent><preventing><priority pathogen><resilience><resilient><resistance frequency><resistance mechanism><resistance to Bacteria><resistance to Bacterial><resistance to Drug><resistant><resistant mechanism><resistant to Bacteria><resistant to Bacterial><resistant to Drug><response><simulation><social role><suicide substrates><transcriptional profiling><transcriptome sequencing><transcriptomic sequencing><transcriptomics><whole genome><β lactam antibiotic><β-Lactamase><β-Lactams>