Antimicrobial activity of cathelicidins BMAP28, SMAP28, SMAP29, and PMAP23 against Pasteurella multocida is more broad-spectrum than host species specific

The antimicrobial activity of linear, cationic alpha-helical peptides from cattle (BMAP28), sheep (SMAP28 and SMAP29), and pigs (PMAP23) were assessed to determine if activity was selective for Pasteurella multocida from a particular animal species or broad-spectrum against all P. multocida tested. The antimicrobial activities of synthetic peptides were determined for P. multocida isolated from cattle (10 isolates), sheep (10 isolates), and pigs (10 isolates) in a broth microdilution assay. All thirty isolates of P. multocida were susceptible to BMAP28 (MICs and MBCs, 1.0-1.9 microM); SMAP28 and SMAP29 (MICs and MBCs, 0.2-0.7 microM); and PMAP23 (MICs and MBCs, 4.3 to > or = 6.8 microM). Overall, the results of this study suggest that synthesized cathelicidins from cattle, sheep, and pigs had broad-spectrum antimicrobial activity against all P. multocida.