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ARS Home » Plains Area » Clay Center, Nebraska » U.S. Meat Animal Research Center » Genetics and Animal Breeding » Research » Publications at this Location » Publication #306333

Title: Pathogen variation across time and space: sequencing to characterize Mannheimia haemolytica diversity

Author
item Clawson, Michael - Mike
item MURRAY, ROBERT - Zoetis

Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 7/29/2014
Publication Date: N/A
Citation: N/A

Interpretive Summary: Mannheimia haemolytica is a species of bacteria that can be found living harmlessly in the upper respiratory tract of cattle. It is also a major pathogen of cattle that can invade the lungs and cause pneumonia and death. The literature suggests that different strains of M. haemolytica vary by their propensity to cause disease, possibly because they differ genetically from each other. To address that notion, the entire genomes of several hundred M haemolytica isolates are being sequenced and analyzed for genetic variation. From the analysis, a test will be developed to identify M. haemolytica with different genetic backgrounds. This test may have utility in detecting M. haemolytica by their propensity to cause respiratory disease in cattle.

Technical Abstract: Bovine Respiratory Disease Complex (BRDC) is a major animal health and economic issue that affects cattle industries worldwide. Within the United States, the beef cattle industry loses up to an estimated 1 billion dollars a year due to BRDC. There are many contributors to BRDC, including environmental stressors, viral, and/or bacterial infections. One species of bacteria in particular, Mannheimia haemolytica, is recognized as the major cause of severe fibrinonecrotic pneumonia in cattle. M. haemolytica is an opportunistic pathogen that normally populates the upper respiratory tract of cattle, and invades the lower respiratory tract in stressed and/or virally infected cattle by mechanisms not completely understood. However, not all M. haemolytica appear to be equally pathogenic to cattle. Thus, a test could be developed that could distinguish M. haemolytica genetic subtypes by their propensity to cause respiratory disease. To that end, the genomes of over 300 M. haemolytica strains are being sequenced.