Molecular Study of Virulence Factors of Pasteurella multocida Isolates from Poultry in Iran

Pasteurella multocida is a Gram-negative, nonmotile, penicillin-sensitive coccobacillus belonging to the pasteurellacea family, and can cause a common infection in humans and animals. P.multocida also important factor in diseases such as fowl cholera in domestic and wild birds, atrophic rhinitis in pigs, cattle and sheep pneumonia or respiratory disease, hemorrhagic septicemia in cattle and buffalo and sniffle disease in the rabbit. The bacteria types that cause Fowl cholera in bird species normally belong to serotypes (A: 1, A: 3 or A: 4). In this study, thirty strains of P.multocida isolated from poultry were studied using bacteriological and biochemical tests according to the classical methods. Several factors are known as virulence factors of P.multocida. The P.multocida isolates studied in this study were obtained from the poultry in Iran and were examined for the presence of virulence factor capsule gene, ompH, and adhesion fimbriae containing genes ptfA, pfhA, tadD, hsf-1, fimA and toxA. All of the isolates were confirmed as P.multocida by PM-PCR using species specific primers, KMT1. Molecular capsular typing (CAP-PCR) showed that all of the isolates belonged to type A. Of the 30 examined isolates, all (100%) contained ompH ¡ptfA¡ pfhA¡ hsf- 1 and fimA genes, fifteen isolates (50%) had tadD gene and 21 isolates (70%) had toxA. Analysis of sensitivity patterns to 9 antibiotics showed relative and complete sensitivity in all the tested samples. Two isolates (3.33%) were resistant to antibiotics Flumequin and Nalidixic Acid. Sensitivity to antibiotics Penicillin, Ampicillin, Lincospectin, Florfenicol, Tylosin and Tiamulin was 100% and complete. Sensitivity to antibiotics Flumequin, Enrofloxacine was observed in 96.6% and sensitivity to Nalidixic Acid was observed in 80 . The results of this study showed that the avian P.multocida isolates had the genes for the important diseases caused by these bacteria. It is concluded that P.multocida has the potential for pathogenicity in birds in Iran.