A Defensin from the Model Beetle Tribolium castaneum Acts Synergistically with Telavancin and Daptomycin against Multidrug Resistant Staphylococcus aureus.

ABSTRACT: The red flour beetle Tribolium castaneum is a common insect pest and has been established as a model beetle to study insect development and immunity. This study demonstrates that defensin 1 from T. castaneum displays in vitro and in vivo antimicrobial activity against drug resistant Staphylococcus aureus strains. The minimum inhibitory concentration (MIC) of defensin 1 against 11 reference and clinical staphylococcal isolates was between 16-64 μg/ml. The putative mode of action of the defensin peptide is disruption of the bacterial cell membrane. The antibacterial activity of defensin 1 was attenuated by salt concentrations of 1.56 mM and 25 mM for NaCl and CaCl2 respectively. Treatment of defensin 1 with the reducing agent dithiothreitol (DTT) at concentrations 1.56 to 3.13 mM abolished t

SUBMITTER: Rajamuthiah R 

PROVIDER: S-EPMC4465704 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature