Characterization and genome analysis of phage vB_KpnS_SXFY507 against Klebsiella pneumoniae and efficacy assessment in Galleria mellonella larvae

Abstract

Carbapenem-resistant Klebsiella pneumoniae is one of the primary bacterial pathogens that pose a significant threat to global public health because of the lack of available therapeutic options. Phage therapy shows promise as a potential alternative to current antimicrobial chemotherapies. In this study, we isolated a new Siphoviridae phage vB_KpnS_SXFY507 against KPC-producing K. pneumoniae from hospital sewage. It had a short latent period of 20 min and a large burst size of 246 phages/cell. The host range of phage vB_KpnS_SXFY507 was relatively broad. It has a wide range of pH tolerance and high thermal stability. The genome of phage vB_KpnS_SXFY507 was 53,122 bp in length with a G + C content of 49.1%. A total of 81 open-reading frames (ORFs) and no virulence or antibiotic resistance related genes were involved in the phage vB_KpnS_SXFY507 genome. Phage vB_KpnS_SXFY507 showed significant antibacterial activity in vitro. The survival rate of Galleria mellonella larvae inoculated with K. pneumoniae SXFY507 was 20%. The survival rate of K. pneumonia-infected G. mellonella larvae was increased from 20 to 60% within 72 h upon treatment with phage vB_KpnS_SXFY507. In conclusion, these findings indicate that phage vB_KpnS_SXFY507 has the potential to be used as an antimicrobial agent for the control of K. pneumoniae.

Characterization of bacteriophage BUCT631 lytic for K1 Klebsiella pneumoniae and its therapeutic efficacy in Galleria mellonella larvae

“…7 C). Moreover, the survival rate increased by 80% upon treatment with phage BUCT631 at an MOI of 10, which was superior to the efficacy of K. pneumoniae phages vB_KpnP_K1-ULIP33 and vB_KpnS_SXFY507 in a G. mellonella infection model ( Feng et al., 2023 ; Thiry et al., 2019 ). These results suggest that phage BUCT631 has potential for clinical application as a therapeutic agent.…”

“…Phages are the most abundant and diverse species in the biosphere, which makes different ecological environments an important source of phages. Targeting hospital-acquired pathogens, hospital sewage provides a resource for phage isolation against drug-resistant bacteria ( Feng et al., 2023 ; Han et al., 2021 ). Phage-bacteria interactions in the environment are complex, and phages only recognize specific bacteria and kill them.…”

Animal models of Klebsiella pneumoniae mucosal infections

“…In the G. mellonella case in particular, the larvae has an innate immune system somewhat similar to ours, but it lacks an adaptative response (Ménard et al, 2021). In K. pneumoniae infection models, G. mellonella has been used with vastly different goals, such as to evaluate phage-mediated survival (Feng et al, 2023), synergistic activity of antimicrobials (Ribeiro et al, 2023) and pathogenicity (Liu et al, 2023). However, when used to compare hypervirulent and common K. pneumoniae strains, the model did not reproduce the same differences observed in outbred mice (Russo and MacDonald, 2020).…”