Figure 7. Expansion of host specificity of ϕSaBov by complementing the tail fiber protein.
(A) For phage spot test, 10 μL of phage lysates (of ϕ11, ϕSaBov, or ϕSaBov complemented with the tail fiber protein of ϕ11 (ϕSaBov-pTF11) containing 1 × 108 pfu/ml was inoculated onto the lawn culture of several pandemic human clones of S. aureus. (B) To measure the efficacy of CRISPR/Cas9 system delivered by ϕSaBov complemented with the tail fiber protein of ϕ11, a mid-exponential culture of pandemic human S. aureus clones (1 × 105 CFU) was treated with phage lysates of ϕSaBov-Cas9-null, ϕSaBov-Cas9-nuc, or ϕSaBov-Cas9-nuc pTF11 at MOI of 100 for 8 h. The bar graph indicates the average and SEM of Log CFU of viable cells, combined from triple measurements of three independent experiments (n = 9). (C) The phage absorption was determined by calculating the proportion of unbound phage from the total phage input (2.5 × 105 pfu) to several pandemic human clones of S. aureus (5 × 107 CFU) at the MOI of 0.005. Asterisk indicates statistical significance in student t-test, compared to the results from ϕSaBov (p < 0.001).