Computer-based analysis of Haemophilus parasuis protein fingerprints.

The present study aimed to compare the whole-cell protein profiles of Haemophilus parasuis field isolates by using a computer-based analysis, and evaluate the relationship between polyacrylamide gel electrophoresis (PAGE) type and virulence potential based on isolation site. A dendrogram clustering isolates with similar protein profiles was generated. Haemophilus parasuis isolates were grouped into 2 major PAGE type groups. The PAGE type II isolates were characterized by the presence of major proteins with molecular weights varying from between 36 and 38 kDa and included 90.7% of the isolates recovered from systemic sites, such as pleura, pericardium, peritoneum, lymph nodes, joints, and brain. Isolates classified as PAGE type I were characterized by the absence of this group of proteins and included 83.4% of the isolates recovered from the upper respiratory tract of healthy animals. The present study further corroborates the existence of a unique group of major proteins in potentially virulent H. parasuis isolates.