In vivo antimicrobial evaluation of an alanine-rich peptide derived from Pleuronectes americanus

► An antimicrobial peptide Pa-MAP exhibited in vivo activity against Escherichia coli. ► Pa-MAP has an effective activity at lower concentrations when compared to other antibiotics. ► Pa-MAP prevents weight loss during infected mice treatment. ► No immunomodulatory activity of Pa-MAP was observed in this study.