Cationic anti-microbial peptides and methods of use thereof

A method comprising:

• (a) contacting a body fluid with a detectably labeled substrate, wherein the substrate comprises a cationic anti-microbial peptide variant consisting of an amino add sequence having at least 90% sequence identity with SEQ ID NO:
• 1 or SEQ ID NO:2 over the entire length of SEQ ID NO:
• 1 or SEQ ID NO:2, respectively, wherein said peptide variant does not comprise SEQ ID NO:3, which is degradable by a proteinase produced and/or secreted by one or more pathogenic bacteria species, under conditions that result in the degradation of the peptide variant by the proteinase, wherein degradation of the peptide variant results in a detectable signal;
• and
• (b) detecting the resulting signal.

A method comprising:

• (a) contacting a sample contacted by body fluid with a detectably labeled substrate, wherein the substrate comprises a cationic anti-microbial peptide variant consisting of an amino acid sequence having at least 90% sequence identity with SEQ ID NO:
• 1 or SEQ ID NO:2 over the entire length of SEQ ID NO:1 or SEQ ID NO:2, respectively, wherein said peptide variant does not comprise SEQ ID NO:3 which is degradable by a proteinase produced and/or secreted by one or more pathogenic bacteria species, under conditions that result in the degradation of the peptide variant by the proteinase, wherein degradation of the peptide variant results in a detectable signal;
• and
• (b) detecting the resulting signal.