Lytic bacteriophage vB_KmiS-Kmi2C disrupts biofilms formed by members of the Klebsiella oxytoca complex, and represents a novel virus family and genus

AIMS This study aimed to characterise the lytic phage vB_KmiS-Kmi2C, isolated from sewage water on a GES-positive strain of Klebsiella michiganensis . METHODS AND RESULTS Comparative phylogenetic and network-based analyses were used to characterise the genome of phage vB_KmiS-Kmi2C (circular genome of 42,234 bp predicted to encode 55 genes), demonstrating it shared little similarity with other known phages. The phage was lytic on clinical strains of K. oxytoca (n=2) and K. michiganensis (n=4), and was found to both prevent biofilm formation and disrupt established biofilms produced by these strains. CONCLUSIONS We have identified a phage capable of killing clinically relevant members of the Klebsiella oxytoca complex (KoC). The phage represents a novel virus family (proposed name Dilsviridae ) and genus (proposed name Dilsvirus ). SIGNIFICANCE AND IMPACT OF THE STUDY Identification a novel lytic phage active against clinically relevant strains of the KoC provides an alternative to antibiotics to treat these increasingly antimicrobial-resistant opportunistic pathogens. The unusual way in which the phage can disrupt established biofilms may allow us to identify novel phage-based approaches for biofilm remediation in the future. ### Competing Interest Statement The authors have declared no competing interest. * CARD : comprehensive antibiotic resistance database KoC : Klebsiella oxytoca complex PC : protein cluster RBP : receptor binding protein SD : standard deviation TEM : transmission electron microscopy TSA : tryptone soy agar TSBG : tryptone soy broth supplemented with 1 % glucose VC : viral cluster VFDB : virulence factor database