FIGURE 4

Combination treatment with phosphatidylserine/phosphatidic acid (PS/PA) liposome and CKΦ in therapeutic administration elicits synergistic effect in antimicrobial activity in wild-type (WT) and decreases phage-resistant PAO1 proliferation in cftr-LOF zebrafish embryos. (A) Schematic representation of combined administration of PS/PA liposome/CKΦ. 48 hpf zebrafish embryos were systemically infected with phage sensitive (PAO1) and/or resistant PAO1 (PAO1-217-2a-GFP) strains, treated with single or combined PS/PA liposome CKΦ 3 h later and analyzed for bacterial burden at 8 or 20 h post infection. (B,C) Bacterial load (relative CFU/embryo) in systemically infected WT (B) and cftr-LOF embryos (C), control (ctrl), PS/PA liposome, CKΦ and PS/PA liposome-CKΦ treated at 8 hpi. (D–G) Bacterial load (relative CFU/embryo) (D,F) and percentage of PAO1-217-2a-GFP colonies (E,G) in embryos systemically infected with 50% phage-sensitive PAO1 (non-GFP) and 50% phage-resistant PAO1-GFP bacterial suspension. WT (D,E) or in cftr-LOF embryos (F,G), control (ctrl), PS/PA liposome, CKΦ and PS/PA liposome-CKΦ treated. (H) Representative image of phage-sensitive PAO1 and phage resistant PAO1-217-2a-GFP colonies derived from the plating of homogenized infected embryos. Statistical significance was assessed by One-way ANOVA test followed by Tukey’s post hoc correction:***p < 0.001; **p < 0.01; *p < 0.05; ns, not significant. Data resulted from three independent experiments and results are presented as mean ± SEM.