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

Abstract

Pasteurella multocida is responsible for numerous economically relevant diseases in domestic animals worldwide. In cattle and buffaloes the organism is associated with hemorrhagic 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 ptfA, nanH, exbBD-tonB and oma87; whereas hgbB and toxA genes occurred less frequently. Some of the adhesions, sialidases, iron acquisition and protectin proteins occurred at considerably (P<0.05) higher frequencies in bovine isolates. the prevalence of oma87, exbBD-tonB and hgbA genes from buffaloes was significant (P<0.05), whereas the prevalence of hgbB, ompH, pfhA and toxA genes was much lower. all tested strains of P. multocida contained the sodC gene and only 22.7% of them had sodA. 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 C1 was the most common, with all strains possessing toxa. Our results indicate the presence of virulence 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.

Investigation of Iron uptake and virulence gene factors (fur, tonB, exbD, exbB, hgbA, hgbB1, hgbB2 and tbpA) among isolates of Pasteurella multocida from Iran

“…The frequency of this gene among different hosts, irrespective of their origin, has been reported from 84.6% to 100%, while it was present in 73.9% of Brazilian rabbit isolates (2,5,6,7,17,19,20). In addition, a previous study on Iranian cattle and buffalo isolates indicated the presence of hgbA gene among 77.2% of all studied isolates (10).…”

“…Moreover, it has been demonstrated that 100% of Iranian and Indian cattle isolates possessed this gene, while some other studies indicated the presence of this gene in 57.4, 57.7, and 61.3% of ovine and cattle isolates from Iran, Germany, and Japan, respectively (2,5,9,(17)(18)(19)(20). In contrast, it has been reported that only 40.9% of Iranian cattle and buffalo isolates from Khuzestan possessed this gene (10).…”

“…Few studies have investigated the association between various hosts and frequency of the mentioned VFs among P. multocida isolates which can significantly increase the current knowledge about its pathogenicity, epidemiology, and development of current vaccinal strains (14,10). Thus, findings of this study can shed light on correlation between the host and frequency of various iron uptake VFs among Iranian P. multocida isolates from different regions and the efficiency of current avian and ovine vaccinal strains on recent field isolates.…”

“…Various virulence factors (VF) found in P. multocida include proteins with functions associated with adherence and colonization (PtfA, FimA, Hsf-1, Hsf-2, Pf hA and TadD), iron acquisition proteins (ExbB, ExbD, TonB, HgbA, HgbB and Fur), extracellular enzymes such as neuraminidases (NanB and NanH) and superoxide dismutases (Soda, SodC and TbpA), hyaluronidase (PmHAS), toxins (ToxA), lipopolysaccharides (LPS), capsular and outer membrane proteins (OmpA, Omph, Oma87 and PlpB) (9,10).…”

“…The presence of sialidases enzymes is crucial in removing these compounds. Additionally, OmpH and PlpE are protective antigens which have been detected in A:1, A:3, and A:4 serotypes from poultry suffered from fowl cholera and cattle with shipping fever (10).…”