ABSTRACT

Pasteurella haemolytica serovar A1 is the causative agent of acute fibrinohemorrahgic pneumonia also known as shipping fever. Many pathogens, including P. haemolytica, survive in their respective hosts through the up-regulation of an iron acquisition system. In this study we identified, purified and characterized a 35-kDa periplasmic iron-regulated protein. The N-terminal sequence of the iron-regulated protein ANEVNVYSYRQP YLIEPMLK was identical to the deduced amino acid sequence of the ferric binding protein, FbpA, of P. haemolytica. Growth of P. haemolytica in a synthetic medium (RPMI-1640), without iron and supplemented with 50 μM 2,2' dipyridyl, facilitated the expression, isolation and purification of the native P. haemolytica FbpA.