Virulence gene profiles of Pasteurella multocida strains isolated from cattle and buffalo

Pasteurella multocida is responsible for numerous economically relevant diseases in domestic animals worldwide. In cattle and buffaloes the organism is associated with orrhagic septicemia (HS) and bovine respiratory disease (BRD). The aim of this study was to investigate twelve virulence associated genes in 22 strains of P. multocida isolated from slaughtered cattle and buffaloes. The most frequently detected genes among bovine isolates were ptfil, nanli, exbBD-tonB and oma87; whereas hgbB and to,1 genes occurred less frequently. Some of the adhesions, sialidases, iron acquisition and proteetin proteins occurred at considerably (P<0.05) higher frequencies in bovine isolates. The prevalence of otna87, ex17BD-tonB and hgbil genes from buffaloes was significant (P<0.05), whereas the prevalence of hgbB, mph`, pfl1,4 and to,4 genes was much lower. All tested strains of P. multocida contained the sodC gene and only 22.7% of them had soli. By using the virulence gene profiles, 12 and 21 different gene combinations were identified among the strains isolated from cattle and buffaloes, respectively, of which Profile Cl was the most common, with all strains possessing toxA. Our results indicate the presence of vindence factors (VFs) in P. multocida strains isolated from the tested cattle and buffaloes. The occurrence of these factors in apparently healthy animals could possibly indicate early infection or a contained infection which did not lead to disease. Moreover, differences in the frequency of these factors may indicate variations in the pathogenicity of the organism.