Fig. 6.

In vitro neutralization of the biological activity CPA toxin. Full-length PLC were left untreated or pre-incubated, in the presence of 4 mM CaCl₂, with serum obtained from a mouse immunized with the non-toxic rBacCPA250–363H6 and the specifically generated MAb 318F11B7. They were then spotted on TSC agar and incubated overnight at 37 °C. The neutralization of PLC activity results in the absence of an outer zone of hydrolysed phospho-lipid. The positive symbol (+) indicate the presence the activity of the toxin while the negative symbol (−) indicate the absence of the activity of the toxin or its complete neutralization. Recombinant truncated rBacCPA250–363H6 protein untreated did not exhibit any lecithinase activity. Representative image of three independent experiments is shown