To provide a peptide having an antibacterial action and useful for methods by which the kinds or strains of bacteria can more simply be judged or identified, or a polynucleotide encoding the same, a recombinant vector or lactobacillus containing the polynucleotide, and antibacterial agents, culture media, medicinal compositions, food or drink additives, animal feed additives, cosmetic additives, antibacterial methods, and methods or kits for judging the kinds of Listeria bactria, the strain of Listeria monocytogenes, the strains of lactic acid bacteria, the strains of Enterococcus or the like.

This peptides each having a specific amino acid sequence comprising a portion of the amino acid sequence of pediocin and a portion of the amino acid sequence of enterocin. The peptide have antibacterial actions, and can be used to more simply judge the kinds or stains of bacteria.