Molecular characterization of Pasteurella multocida isolates obtained from poultry, ruminant, cats and dogs using RAPD and REP-PCR analysis

In the present study, Randomly Amplified Polymorphic DNA (RAPD) and Repetitive Extragenic Palindromic sequence-based Polymerase Chain Reaction (REP-PCR) were used to characterize 131 isolates of Pasteurella multocida, originating from different healthy and diseased animal species obtained from several geographical regions of Iran. The RAPD and REP-PCR generated amplified products in the range of 300 to 3400 bp and 200 to 2850 bp, respectively. Among all of the P. multocida isolates, cluster analysis revealed that 63 clusters and nine untypable isolates and 81 clusters and six untypable isolates were produced with RAPD and REP-PCR methods, respectively. The results indicated that the REP-PCR method showed a slightly higher level of discrimination power in differentiating of P. multocida isolates as compared with RAPD. The results showed that a considerable level of genetic diversity exists among P. multocida isolates even in the isolates with the same animal or geographical origins. There was no host- and region-specific pattern. In addition, the isolates obtained from the healthy and diseased animal did not reveal any correlation genotypic profiles, which could be supported by the hypothesis that P. multocida is a strictly opportunistic pathogen. In conclusion, because of a large amount of genetic heterogeneityin the P. multocida isolates, Pasteurellosis may be caused by different clones in the same herd or animal.