Immunoblot analysis of optA, optB, LfliC and Lhly antigens expressed in JOL1800 derived strains, JOL1809, JOL1810, JOL1811 and JOL1812, respectively. The respective vaccine strains were grown in LB broth to mid-log phase and then the culture supernatants were collected and subjected to Western blot analysis using protein-specific hyperimmune sera raised in rabbits. The expression plasmid, pJHL65 transformed into JOL912 was used as a vector control. The predicted molecular mass of the expressed recombinant proteins were ~17 kDa for OptA, ~41.1 kDa for OptB, ~38.6 kDa for FliC and ~30 kDa for Hly. Lane M, size marker; lane C, vector control; lane OptA, a pellet of JOL1809; lane OptB, a pellet of JOL1810; lane FliC, a pellet of JOL1811; lane Hly, a pellet of JOL1812.