Molecular identification and capsular typing of Pasteurella multocida isolates from sheep pneumonia in Iran

Pasteurella multocida is known as one of the main organisms causing pneumonia in sheep. As immunity in pasteurellosis is serogroup specific, identification of prevalent capsular group among endemic areas is essential. The aim of this study was to molecular identification and determine of the capsular type of the P. multocida strains isolated from sheep pneumonia in Iran. Bacteriological and biochemical characterization was confirmed by species specific PM-PCR.  Genomic DNA was extracted by boiling method. Capsular typing was conducted by using type specific primers via Cap-PCR method. The PCR product was sequenced and analysed by BLAST software. The biochemical identification was confirmed by a species-specific PCR assay (PM-PCR). According to Cap-PCR results, all of the 52 P.multocida isolates belonged to the capsular type A. The PCR amplified a fragment of 1044 bp from all of tested isolates. The sequence alignment of the CAP-PCR product showed a high similarity (>98%) with the published sequences of P.multocida hya gene in the Gene Bank. It was found that capsular type A is dominant among P. multocida isolates from sheep pasteurellosis in endemic areas of Iran. Investigation on preparation and evaluation of an effective sheep pasteurellosis vaccine by using ovine isolates of P.multocida capsular type A is recommended.