Methods, peptides, and biosensors useful for detecting a broad spectrum of bacteria

A method for detecting the presence or absence of a wound-specific bacterium, wherein the wound-specific bacterium is one or more of Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa, Enterococcus faecalis, and Serratia marcescens, in a sample selected from a wound surface, a body fluid, or fluid from a wound, comprising:

• a) contacting the sample with a detectably labelled synthetic α1-proteinase inhibitor reactive site loop domain peptide substrate set forth in SEQ ID NO:2 under conditions that result in cleavage of said peptide substrate by an enzyme produced by the wound-specific bacterium;
• and
• b) detecting a cleavage or an absence of the cleavage of the peptide substrate, the cleavage of the peptide substrate indicating the presence of the wound-specific bacterium in the sample and absence of cleavage of the peptide substrate indicating absence of the wound-specific bacterium in the sample.