Novel use for cationic peptides as anti-bacteriophage agent. Its relevance on Escherichia coli O157:H7 Shiga Toxin-Encoding Bacteriophages.

LETICIA BENTANCOR; AXEL HOLLMANN; DEL COGLIANO ME; MAFFIA P; MARTINEZ MELINA; GHIRINGHELLI DANIEL; TORRES PABLO ARIEL

Paris

Conferencia; Bacteriophage Conference 2017; 2017

Eliava Institute / Pasteur Institute

Shiga toxin (Stx) is the main virulence factor in Escherichia coli O157:H7 Shiga Toxin-Encoding Bacteriophages. Cationic antimicrobial peptides (cAMPs) have shown effects on multiresistant bacteria. Previously we reported inactivation of bacteriophage encoding Stx after chitosan treatment, which is a linear polysaccharide polymer with cationic properties. With the aim to evaluate if cationic properties are responsible for bacteriophage inactivation, we tested seven cationic peptides as anti-bacteriophage agents, six of them with proven antimicrobial activity, and one random sequence cationic peptide with no antimicrobial activity. We observed bacteriophage inactivation after incubation with five cAMPs, but no neutralizing activity was observed with the random cationic peptide nor with the non alpha helical cAMP Omiganan. Finally to confirm peptide-bacteriophage interaction zeta potential was analyzed by following changes on bacteriophage surface charges after peptide incubation. Overall our data suggest that: 1. Direct interaction of peptide with phage is a necessary step for inactivation of bacteriophage, 2. Charges alteration of the bacteriophage are relevant for infection and 3. Neutralization by cationic peptides is sequence specific. Those peptides could be used to avoid infection of intestinal bacteria, consequently avoiding bacteriophage replication and stx expression.