PLASMIDS FOR HETEROLOGOUS EXPRESSION IN PASTEURELLA-HAEMOLYTICA

New cloning and expression vectors that replicate both in Pasteurella haemolytica and in Escherichia coli were constructed based on a native sulfonamide (Su(R)) and streptomycin (Sm-R) resistant plasmid of P. h aemolytica called pYFCl. Each shuttle vector includes an MCS and a sel ectable antibiotic resistance marker that is expressed in both organis ms. Plasmid pNF2176 carries the P. haemolytica ROB-1 beta-lactamase ge ne (blaP, Ap(R)) and pNF2214 carries the Tn903 aph3 kanamycin resistan ce (Km(R)) element. The expression vector, pNF2176, was created by pla cing the MCS downstream of the sulfonamide gene promoter (P-sulII) on pYFCl; this was used to clone and express the promoterless Tn9 chloram phenicol resistance gene (cat, Cm-R) in P. haemolytica (pNF2200). A pr omoter-probe vector (pNF2283) was constructed from pNF2200 by deleting P-sulII.