Histophilus somni: Antigenic and Genomic Changes Relevant to Bovine Respiratory Disease.

Histophilus somni is associated with several disease syndromes in cattle and plays an important role in the bovine respiratory disease complex. H somni isolates exhibit significant differences in terms of susceptibility to inactivation by normal serum corresponding to the general ability to cause clinical disease. Isolates possess a variety of virulence factors, and variation in virulence factor expression is well recognized and associated with antigenic differences. Sequencing of genes associated with known virulence factors has identified genetic variability between isolates. The antigenic and genomic differences represent significant challenges to the host immune system and are problematic for vaccine design.
Competing Interests: Disclosure The author is employed by Newport Laboratories, owned by Boehringer Ingelheim. Newport Laboratories operates a private veterinary diagnostic laboratory and autogenous biologic manufacturing facility utilizing some of the technologies described in this article.
(Copyright © 2020 Elsevier Inc. All rights reserved.)