Transcription response of Staphylococcus aureus to the antibacterial peptides

Fungi and bacteria are commonly sympatric in nature and antibacterial substances secretion is one of the strategies fungi evolved to compete with bacteria with limited nutrients or other factors. Therefore, fungi are recognized as newly emerging sources of antibacterial peptide production. In this study, we report two novel antibacterial peptides, p-PN and p-CL obtained from the genome of fungi Pichia norvegensis and Clavispora lusitaniae, which are symbiotic fungal species of the human intestine. With high amino acid sequence similarity, both p-PN and p-CL showed strong antibacterial activities in the Gram-positive bacteria Staphylococcus aureus, not only in the antibiotic-sensitive isolates but also the drug-resistant isolates, including methicillin- and vancomycin-resistant isolates at low concentrations.