Investigation of morphological changes toStaphylococcus aureusinduced by ovine-derived antimicrobial peptides using TEM and AFM

The effect of two ovine-derived peptides on the morphology of Staphylococcus aureus NCTC 4163 cells were investigated using transmission electron microscopy and atomic force microscopy. Both techniques showed that SMAP29, an alpha-helical peptide, induced cell lysis, whereas OaBac5mini, a proline/arginine-rich peptide, caused no observable morphological changes. This is consistent with previous experimental work which indicated that SMAP29 caused cell death and induced cell lysis, whereas OaBac5mini acted by interacting with the inner cellular contents.