摘要Severe infections caused by multidrug-resistant Klebsiella pneumoniae(K.pneumoniae)highlight the need for new therapeutics with activity against this pathogen.Phage therapy is an alternative treatment approach for multidrug-resistant K.pneumoniae infections.Here,we report a novel bacteriophage(phage)BUCT631 that can specifically lyse capsule-type K1 K.pneumoniae.Physiological characterization revealed that phage BUCT631 could rapidly adsorb to the surface of K.pneumoniae and form an obvious halo ring,and it had relatively favorable thermal stability(4-50 ℃)and pH tolerance(pH=4-12).In addition,the optimal multiplicity of infection(MOI)of phage BUCT631 was 0.01,and the burst size was approximately 303 PFU/cell.Genomic analysis showed that phage BUCT631 has double-stranded DNA(total length of 44,812 bp)with a G+C content of 54.1％,and the genome contains 57 open reading frames(ORFs)and no virulence or antibiotic resistance related genes.Based on phylogenetic analysis,phage BUCT631 could be assigned to a new species in the genus Drulisvirus of the subfamily Slopekvirinae.In addition,phage BUCT631 could quickly inhibit the growth of K.pneumoniae within 2 h in vitro and significantly elevated the survival rate of K.pneumoniae infected Galleria mellonella larvae from 10％to 90％in vivo.These studies suggest that phage BUCT631 has promising potential for development as a safe alternative for control and treatment of multidrug-resistant K.pneumoniae infection.