Characterization of bubaline and avian vaccine strains of Pasteurella multocida from Razi institute as displayed by the Australian version of Multi Locus Sequence Typing analysis

Hemorrhagic septicemia (HS) is principally an infectious disease of respiratory tract caused by Pasteurella multocida in ruminants and birds resulting in huge economic repercussions. In the mid 1930s and early 1980s the Iranian buffalo (Pm Razi0001) and chicken (Pm Razi0002) strains of Pasteurella multocida were collected respectively from diseased animals. These strains have been used ever since for preparation of pasteurellosis vaccine at Razi institute. Multi Locus Sequence Typing (MLST) analysis is a standard method of genotyping for P. multocida. This was conducted to assess genomic structure of the vaccine P. multocida strains at Razi institute. Genomic material was prepared from freshly cultured strains through a simplified boiling protocol. KMT1-PCR was used to authenticate identity of strains as P. multocida. The Australian RIRDC-MLST typing system targeting 7 housekeeping genes of adk, est, pmi, zwf, mdh, gdh and pgi loci with few modifications was performed on strains. The Sequence Type (ST) and the corresponding clonal complex of the strains was determined by consulting the RIRDC-MLST database. Two STs were identified with ST352 (a subgroup of clonal complex CC122) and ST129 (a subgroup of clonal complex CC129) assigned for the buffalo (Pm Razi0001) and fowl (Pm Razi0002) strains, respectively. If using these strains as vaccine for all the past consecutive decades has had major impacts in population and epidemiology of P. multocida in this country, much more work is required.