Proffered Papers Australian Society for Microbiology Annual Scientific Meeting 2016

Evaluation of novel inhibitors against Burkholderia pseudomallei Mip protein (#135)

Mitali Sarkar-Tyson 1 2 , Isobel Norville 1 , Laura Marshall 1 , Nicole Bzdyl 2 , Florian Seufert 3 , Ulrike Holzgrabe 3
  1. Microbiology, Dstl, Salisbury, Wiltshire, UK
  2. School of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Western Australia, University of Western Australia, Perth, WA, Australia
  3. Institute of Pharmacy and Food Chemistry, University of Wuerzburg, Wuerzburg, Germany

Burkholderia pseudomallei, the causative agent of melioidosis is a disease endemic in South East Asia and Northern Australia. There is currently no vaccine available against B. pseudomallei and the organism is resistant to a range of antibiotics. Therefore identification of new drug targets is essential. The Macrophage infectivity potentiator (Mip) protein is a virulence factor encoded by intracellular pathogens. The Mip protein in B. pseudomallei  exhibits virulence-associated peptidyl-prolyl cis-trans isomerase (PPIase) activity, inhibition of which potentially represents a novel target for antimicrobial therapies to this organism. B. pseudomallei Mip was shown to be required for full virulence in vivo. Recombinant B. pseudomallei Mip protein exhibits PPIase activity which is inhibitable by rapamycin and FK506. A group of pipecolic acid derivatives have been shown to inhibit Mip from Legionella pneumophila. Using a protease coupled PPIase assay, we have demonstrated that a selection of these pipecolic acid derived compounds also have inhibitory properties against the recombinant B. pseudomallei Mip. Importantly, these inhibitors reduce the cytotoxic effects of B. pseudomallei on macrophages.