Figure 1. Recombinant mc²-CMX vaccine containing pLA71/CMX DNA expressed the recombinant protein and persisted in mice.

(A) The recombinant CMX protein (38 kDa) expressed from the mc²-CMX vaccine was only detected when analyzed with an anti-CMX polyclonal antibody. Cross-reactivity with Ag85 and MPT-51 proteins was also observed. Lane M: BlueStep™ Broad Range Protein Marker (Amresco); lane 1: purified recombinant CMX protein; lanes 2 and 3: mc²-CMX; lanes 4 and 5: mc². (B) To check that the live vaccine survived in vivo and retained the plasmid, spleen homogenates from vaccinated mice were plated on antibiotic-containing medium and the retrieved colonies were tested by PCR for the presence of the CMX fusion gene. All the isolated colonies showed a positive PCR. Lane M, Axygen 100 bp DNA Ladder (Biosciences); lanes 1–5: colonies of bacteria recovered and tested by PCR; lane 6, negative PCR control.