Characterization of phage resistance and phages capable of intestinal decolonization of carbapenem-resistant Klebsiella pneumoniae in mice

Abstract

Carbapenem-resistant Klebsiella pneumoniae (CRKP) has emerged as a severe global health challenge. We isolate and characterize two previously unidentified lytic phages, P24 and P39, with large burst sizes active against ST11 KL64, a major CRKP lineage. P24 and P39 represent species of the genera Przondovirus (Studiervirinae subfamily) and Webervirus (Drexlerviridae family), respectively. P24 and P39 together restrain CRKP growth to nearly 8 h. Phage-resistant mutants exhibit reduced capsule production and decreased virulence. Modifications in mshA and wcaJ encoding capsule polysaccharide synthesis mediate P24 resistance whilst mutations in epsJ encoding exopolysaccharide synthesis cause P39 resistance. We test P24 alone and together with P39 for decolonizing CRKP using mouse intestinal colonization models. Bacterial load shed decrease significantly in mice treated with P24 and P39. In conclusion, we report the characterization of two previously unidentified lytic phages against CRKP, revealing phage resistance mechanisms and demonstrating the potential of lytic phages for intestinal decolonization.

Effective phage cocktail to combat the rising incidence of extensively drug-resistant Klebsiella pneumoniae sequence type 16

“…Although some isolates were genetically related by PFGE (Table S1), they varied in phage susceptibility (Figure S1). Point mutations on phage receptors, alteration of receptor expression or capsule production can modify the phage susceptibility exhibited by a strain [ 19 , 20 ]. Thus, we suggested that we should not only rely on the PFGE clonal relationship of different strains to predict phage susceptibility.…”

Construction and Characterization of T7 Bacteriophages Harboring Apidaecin-Derived Sequences

“…Since apidaecin and its analogs inhibit protein translation by targeting the 70S ribosome [ 26 ], we expected an effect on phage production. This effect could reduce phage-mediated lysis but might also reduce the emergence and growth of phage-resistant bacteria, which frequently happens after the initial lysis phase [ 27 , 28 , 29 ]. Phage-mediated lysis started 2 h after phage addition and regrowth of an E. coli Rosetta DE3 pLysS population, which was potentially phage-resistant, was observed with a maximal growth 24 h after the initial lysis in growth experiments with T7select phage without the addition of apidaecin ( Figure 2 B).…”

Genetic determinants of host tropism inKlebsiellaphages

“…This is in line with recent results in Vibrio sp., where phage infection varied across closely related strains due to post-adsorptive mechanisms (Hussain et al, 2021; Piel et al, 2021). Still, establishing solid associations between RBDs and pre-adsorptive phage activity might be useful from a phage therapy point of view, since degradation of the capsule by phages might help the immune system and/or antibiotics to clear infection (Fang et al, 2022; Gordillo Altamirano et al, 2021).…”