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Biology subjects

Doherty, H. M.

Publications and source records attributed to Doherty, H. M..

3 recordsLinked to original sources

Restoring Antibiotic Sensitivity via Metabolic Pathway Manipulation in Pseudomonas aeruginosa

Stopping antimicrobial multidrug resistance (AMR) is essential to maintain the efficacy of current treatments and sustain modern medicine, but current control relies on a coordinated One Health approach involving stewardship, infection prevention and other control measures, without direct actionable mechanisms against resistance itself. Here, integrating proteomics and metabolomics with high-throughput Caenorhabditis elegans infection models, we show that unique synergy of biotin biosynthesis inhibition with metformin uncouples virulence from bacterial viability shutting down major Pseudomonas aeruginosa (PA) virulence mechanisms that impair host survival. Under directed evolution induced by central carbon metabolic stress, laboratory and clinical PA strain isolates acquire mutations in the MexAB-OprM multidrug efflux pump, leading to reversal of the AMR phenotype and restored susceptibility to multiple legacy and last-resort antibiotics such as meropenem. Our findings reveal a previously unexploited vulnerability in PA, its co-dependence on biotin biosynthesis and energy metabolism for virulence and resistance. This work establishes a conceptual framework in which metabolic co-targeting can abolish pathogenesis and drive reversal of antimicrobial resistance. It lays the foundation for first-in-class, non-antibiotic PA-selective anti-virulence and resistance-reversing therapies, key to extending the lifesaving duration of existing antibiotics.

microbiology↗

Bam complex associated proteins in Escherichia coli are functionally linked to peptidoglycan biosynthesis, membrane fluidity and DNA replication

Biogenesis of the bacterial outer membrane is key to bacterial survival and antibiotic resistance. Central to this is the {beta}-barrel assembly machine (Bam) complex and its associated chaperones, which are responsible for transport, folding and insertion of outer membrane proteins (OMPs). The Escherichia coli Bam complex is composed of two essential subunits, BamA and BamD, and three non-essential accessory lipoproteins, BamB, BamC and BamE. Optimal Bam function is further dependent on the non-essential periplasmic chaperones DegP, Skp and SurA. Despite intensive study, the specific function of these non-essential Bam-associated proteins is not fully understood. Here, we analysed {Delta}bamB, {Delta}bamC, {Delta}bamE, {Delta}surA, {Delta}skp and {Delta}degP knockout strains by phenotypic screening, conservation analysis and high-throughput genetics. We identify hundreds of synthetic-lethal interactions and reveal that Bam complex activity is impacted by changes in outer membrane lipid composition and that enterobacterial common antigen is essential in the absence of the chaperone SurA. We also show genes responsible for synthesis of peptidoglycan are synthetically-lethal with Bam accessory lipoprotein encoding genes. Together, our data indicates potential mechanisms for coordination of OMP biogenesis with other cellular growth processes such as LPS and peptidoglycan biogenesis.

microbiology↗

ChemGAPP; A Package for Chemical Genomics Analysis and Phenotypic Profiling.

High-throughput chemical genomic screens produce informative datasets, providing valuable insights into unknown gene function on a genome-wide level. However, there is currently no comprehensive analytic package publicly available. We developed and benchmarked ChemGAPP to bridge this gap. ChemGAPP allows integration of various steps in a streamlined and user-friendly format, including rigorous quality control measures to curate screening data. ChemGAPP provides three sub-packages for different chemical-genomic screens: ChemGAPP Big for handling large-scale high-throughput screens; ChemGAPP Small, designed for small-scale screen analysis and ChemGAPP GI for genetic interaction screen analysis. ChemGAPP is available at https://github.com/HannahMDoherty/ChemGAPP.

bioinformatics↗