Journal article

Fluorescent Trimethoprim Conjugate Probes To Assess Drug Accumulation in Wild Type and Mutant Escherichia coli

Wanida Phetsang, Ruby Pelingon, Mark S Butler, KC Sanjaya, Miranda E Pitt, Geraldine Kaeslin, Matthew A Cooper, Mark AT Blaskovich

ACS Infectious Diseases | AMER CHEMICAL SOC | Published : 2016


Reduced susceptibility to antimicrobials in Gram-negative bacteria may result from multiple resistance mechanisms, including increased efflux pump activity or reduced porin protein expression. Up-regulation of the efflux pump system is closely associated with multidrug resistance (MDR). To help investigate the role of efflux pumps on compound accumulation, a fluorescence-based assay was developed using fluorescent derivatives of trimethoprim (TMP), a broad-spectrum synthetic antibiotic that inhibits an intracellular target, dihydrofolate reductase (DHFR). Novel fluorescent TMP probes inhibited eDHFR activity with comparable potency to TMP, but did not kill or inhibit growth of wild type Esch..

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University of Melbourne Researchers


Awarded by NHMRC

Awarded by Wellcome Trust

Awarded by ARC

Funding Acknowledgements

M.A.C. is supported by a NHMRC Principal Research Fellowship (APP1059354), W.P. and S.K. are supported by a UQ International Scholarship (UQI) and IMB Postgraduate Award (IMBPA), and M.P. is supported by an Australian Postgraduate Award (APA) Ph.D. scholarship. RP., M.A.T.B., M.S.B., and G.K. are supported in part by Wellcome Trust Strategic Grant WT141107. Imaging work was performed in the Queensland Brain Institute's Advanced Microscopy Facility and generously supported by ARC LIEF LE130100078. We thank Luke Alexander Hammond for training and data analysis. The wild type and mutant tolC and lpxC and double-mutant E. coli strains MB4827, MB4902, MBS746, and MBS747 were generously supplied by Merck Sharp & Dohme (Kenilworth, NJ, USA).