Nucleic acid and protein profile of Pasteurella multocida of avian origin

Abstract

Four avian field isolates (one from quail and three from ducks) suggestive of Pasteurella sp. were compared with the avian Pasteurella multocida reference strain (LKO) for their biochemical properties, drug resistance patterns, whole cell and outer membrane protein profiles and restriction enzyme digestion pattern of chromosomal DNA. Biochemical characterisation revealed two biotypes among the four field isolates; namely P. multocida subsp. septica (quail isolate) and P. multocida subsp. multocida (duck isolates). The study of antibiogram using 14 chemotherapeutic agents revealed the presence of multiple drug resistance in all the four field isolates and reference strain. Whole cell protein profiles of the four field isolates and reference strain revealed 7 to 11 bands of molecular weights ranging from 197.4 kDa to 2.5 kDa. Polypeptide bands in the molecular weight range of 36 to 38 kDa (which were attributable to the protein-H), 29 to 32 kDa and 10 to 11 kDa were common to all the isolates of P. multocida. The major outer membrane proteins (OMPs) in the molecular weight range of 32 to 33 kDa and 27 kDa region were common to all the four field isolates and reference strain.

II Unique protein bands in each of the isolate were indicative of variant forms of the same organism. Restriction enzyme analysis of chromosomal DNA yielded different restriction fragments in each of the isolates which were not easily distinguishable. Hence, of the tests used, phenotypic characters, biotype, antibiogram and protein profile were found to be more effective in differentiating the isolates rather than restriction enzyme digestion patterns of genomic DNA.