Isolation and Characterization of Lytic Phage TUN1 Specific for Klebsiella Pneumoniae K64 Clinical Isolates From Tunisia

Abstract

Background Multidrug-resistant Klebsiella pneumoniaespp (Kp) are emerging agents of severe infections of the respiratory and urinary tract or wounds, and progression to fatal septicemia. The use of bacteriophages is currently being considered as an effective alternative or adjuvant to antibiotic treatment. Results In this study, we report K-typing of 163 carbapenem-resistant Kp (CRKP) isolated 2014–2018 at the Military Hospital of Instruction of Tunis (MHT), Tunisia, using wzi gene sequencing. Thereby, we found that K64 Kp strains are associated with increased case/fatality rates, especially at the intensive care unit (ICU). Furthermore, we characterized a lytic Kp phage, vB_KpP_TUN1 (phage TUN1), isolated from waste water samples of the ICU at the MHT. Whole genome sequencing showed that this phage belongs to the Podoviridae family and encodes one putative depolymerase specifically digesting K64 Kp capsules. Furthermore, we could successfully assemble phage TUN1 in a non-replicative host (E. coli) raising the possibility of in vitro assembly in the absence of live bacterial hosts. Therefore, phage TUN1 is a promising candidate to be used as an adjuvant or an alternative to antibiotic therapy in CRKP infections, facilitating regulatory approval of phage therapy. Conclusions The lytic phage TUN1, efficiently lyses K64 Kp strains associated with increased case/fatality rates at body temperature. Together with its ability to be rescued in a non-replicative host these features enhance the utility of this phage as antibacterial agent.

Isolation and characterization of novel bacteriophage vB_KpP_HS106 for Klebsiella pneumonia K2 and applications in foods

“…It can be less costly to reproduce a large number of bacteriophages with a smaller MOI and a shorter incubation period (Abedon, 1989). In this study, Phage HS106 was determined to have an optimal MOI of 0.001 and an incubation period of 10 min, which was considerably better than other K. pneumoniae phages, including vB_KpnP_Bp5 (Zhang et al, 2021), vB_KleS-HSE3 (Peng et al, 2020), and vB_KpP_ TUN1 (Eckstein et al, 2021), etc. The burst size of phage HS106 was Effects of phage vB_KpP_HS106 on the viability of K. pneumoniae 106 in foods.…”

“…10. 3389/fmicb.2023.1227147 Frontiers in Microbiology 10 frontiersin.org larger than phage TUN1 (Eckstein et al, 2021). In brief, phage HS106 has a smaller optimal MOI, a shorter latent period, and a larger burst size, which indicates higher growth efficiency.…”

Appelmans Protocol forin vitro Klebsiella pneumoniaephage host range expansion leads to induction of a novel temperate linear plasmid prophagevB_KpnS-KpLi5

“…Phages N15 (E. coli), phiKO2 (K. oxytoca), PY54 (Yersinia enterocolitica), VP882, VP58.5, VHML etc. (Vibrio species) are extrachromosomally resident in their hosts [9].…”