Fig. 2
Construction of the Δcrp mutant in the P. multocida 0818 strain. a Schematic of the strategy used for deletion of the target crp gene (PM1157). The P. multocida crp gene was replaced with a kanR cassette via homologous recombination. Three pairs of primers, 1& 2, 3& 4, and 5& 6, were designed to select and characterize the mutant clones. b Characterization of the constructed Δcrp mutant via PCR. The parent strain and Δcrp mutant were identified using the primers 1&2, 3&4 and 5&6. M refers to the DNA marker; 16sRNA indicates amplification of the positive gene in both strains. c Detection of Crp expression in P. multocida stains. The parent strain, S416 (Δcrp) and S416 (pQK176) were grown in BHI media and collected at an OD600 of 1.0, and the expression of Crp was then measured in these strains with an anti-Crp antibody via western blotting. Crp refers to purified protein and served as a positive control