A total of 262 sample were collected as 148 nasal swabs of cows (n=82) and buffales (n=66) were collected from apparently healthy and diseased animals of different ages and 114 lung samples of cows (n=60) and buffales (n=54) were collected from apparently healthy, diseased emergency slaughtered and recently dead animals. The bacteriological investigation showed that 23 Pasteurella multocida suspected isolates from 262 of total samples with a percentage
8.8%. All suspected colonies (n=23) were reinvestigated using VITEK2 compact system and the results revealed isolation of 23 Pasteurella multocida strains. The use of molecular techniques for detection and characterization of the Pasteurella multocida is very important for rapid and specific detection and characterization of the organism and its virulence factor.
PCR assays were used for detection of Pastuerella multocida toxA gene in examined samples. In the present study, Pastuerella multocida toxin analyzed strains showed a band at 864bp. Out of 23 positive Pasturella multocida isolates, only 11 Pasteurella multocida isolates were proved to be toxigenic strains with incidence of 47.8%. In conclusion, toxigenic strains of Pasteruella multocida play an important role in its pathogenesis.So differentiation of toxigenic and non-toxigenic strains of Pasteurella multocida is essential for the accurate diagnosis, treatment, and prevention of diseases caused by Pasteurella multocida. Using PCR is highly sensitive and specific for toxA gene detection.

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