Virulence genes and antimicrobial resistance of Pasteurella multocida isolated from poultry and swine

Pasteurella multocida causes atrophic rhinitis in swine and fowl cholera in birds, and is a sec-ondary agent in respiratory syndromes. Pathogenesis and virulence factors involved are stillpoorly understood. The aim of this study was to detect 22 virulence-associated genes by PCR,including capsular serogroups A, B and D genes and to evaluate the antimicrobial susceptibil-ity of P. multocida strains from poultry and swine. ompH, oma87, plpB, psl, exbD-tonB, fur, hgbA,nanB, sodA, sodC, ptfA were detected in more than 90% of the strains of both hosts. 91% and92% of avian and swine strains, respectively, were classified in serogroup A. toxA and hsf-1showed a significant association to serogroup D; pmHAS and pfhA to serogroup A. Gentamicinand amoxicillin were the most effective drugs with susceptibility higher than 97%; however,76.79% of poultry strains and 85% of swine strains were resistant to sulphonamides. Fur-thermore, 19.64% and 36.58% of avian and swine strains, respectively, were multi-resistant.Virulence genes studied were not specific to a host and may be the result of horizontaltransmission throughout evolution. High multidrug resistance demonstrates the need forresponsible use of antimicrobials in animals intended for human consumption, in additionto antimicrobial susceptibility testing to P. multocida