Defeating the superbugs

A research team led by the UK's National Physical Laboratory (NPL) is homing on how antimicrobial peptides bind with bacterial membranes and punch holes in them that lead to their disgorging the contents and dying. The team has gained new insight into AMP behavior by modeling a de novo AMP and a supported lipid bilayer model and using atomic force microscopy to obtain a clear view at the nanoscale. AFM provides topographical imaging of the peptide-treated membrane while chemical analysis is done with high-resolution nanoscale secondary ion mass spectroscopy (NanoSIMS). Team leader Paulina Rakowska says that these observations provide the first-ever evidence of antimicrobial pore expansion from nano-to-micrometer scale to the point of complete membrane disintegration. This should allow chemists to figure out the bare essentials of active AMPs and perhaps to design optimal versions with activity against multiple-resistant bacterial strains.