We performed the in silico genome-wide identification of antimicrobial peptides against the available genome sequence of the naked mole rat Heterocephalus glaber (H. glaber). Our results showed the presence of Hg-CATH， the single cathelicidin containing the antimicrobial domain in H. glaber. We chemically synthesized a 25 amino-acid peptide (ΔHg-CATH) corresponding to the predicted antimicrobial-active core region of Hg-CATH， and evaluated its antibacterial activity against seven bacterial strains. The ΔHg-CATH peptide exhibited strong bactericidal activity against gram-negative bacteria， including a multi-drug resistant strain， while showing low toxicity towards mammalian cells， including erythrocytes. Scanning electron microscopy images of bacterial cells treated with ΔHg-CATH showed disruption of their membranes due to the formation of toroidal pores. Identifying novel antimicrobial peptides， such as Hg-CATH， may be important for identifying candidate peptides for the control of multi-drug resistant bacteria.