Microcin H47: A Class IIb Microcin with Potent Activity Against Multi-Drug Resistant Enterobacteriaceae .

Microcin H47 (MccH47) is an antimicrobial peptide produced by some strains of , that has demonstrated inhibitory activity against enteric pathogens in vivo, and has been heterologously overexpressed in proof-of-concept engineered probiotic applications. While most studies clearly demonstrate inhibitory activity against isolates, there are conflicting results on the qualitative capacity for MccH47 to inhibit strains of . Here we rectify these inconsistencies via the overexpression and purification of a form of MccH47, here termed MccH47-MGE. We then use purified microcin to estimate minimum inhibitory concentrations (MICs) against a number of medically-relevant , including and numerous multi-drug resistant (MDR) strains. While previous reports suggested that the spectrum of activity for MccH47 is quite narrow and restricted to activity against , our data demonstrate that MccH47 has broad and potent activity within the family, suggesting it as a candidate for further development towards treating MDR enteric infections.