Author
Clawson, Michael - Mike | |
MURRAY, ROBERT - Zoetis | |
SWEENEY, MICHAEL - Zoetis | |
APLEY, MICHAEL - Kansas State University | |
DEDONDER, KEITH - Kansas State University | |
CAPIK, SARA - Kansas State University | |
LARSON, ROBERT - Kansas State University | |
LUBBERS, BRIAN - Kansas State University | |
KALBFLEISCH, THEODORE - University Of Louisville | |
Schuller, Genevieve - Gennie | |
Harhay, Gregory | |
Heaton, Michael - Mike | |
Chitko-Mckown, Carol | |
Workman, Aspen | |
Harhay, Dayna | |
Bono, James - Jim | |
Smith, Timothy - Tim |
Submitted to: Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 3/26/2015 Publication Date: 6/1/2015 Citation: Clawson, M.L., Murray, R.W., Sweeney, M.T., Apley, M.D., DeDonder, K.D., Capik, S., Larson, R., Lubbers, B.V., Kalbfleisch, T.S., Schuller, G., Harhay, G.P., Heaton, M.P., Chitko-McKown, C.G., Workman, A.M., Harhay, D.M., Bono, J.L., Smith, T.P.L. [abstract]. 2015. Identification of a mannheimia haemolytica genetic subtype that causes bovine respiratory disease. American Society for Microbiology 2015, 115th General Meeting, May 30-June 2, 2015, New Orleans, LA. Poster #1410. Interpretive Summary: Technical Abstract: Bovine respiratory disease complex (BRDC) is a serious health and economic problem that costs the United States cattle industry over a billion dollars annually. Mannheimia haemolytica is a major bacterial component of BRDC. An opportunistic pathogen, M. haemolytica resides within the upper respiratory tract of cattle, and invades the lower respiratory tract when animals are stressed or immunocompromised, where it can cause severe fibrinonecrotic pneumonia. Importantly, M. haemolytica appear to be genetically diverse, and not all members of the species have demonstrated equal pathogenicity to cattle. Accordingly, the goals of this project were to sequence the genomes of M. haemolytica strains isolated from either diseased or healthy cattle, characterize nucleotide sequence variation across the genome, and compare genetic diversity between strains isolated from sick vs healthy cattle. To accomplish this, 317 M. haemolytica strains were selected for whole-genome sequencing that were isolated from diseased beef and dairy cattle across 35 USA states and 6 Canadian provinces, as were 31 strains that were isolated from cattle that were not afflicted with respiratory disease from 3 USA states. The genomes of all 348 strains were sequenced to a minimum depth of 10X coverage and the reads were mapped to a reference M. haemolytica genome to identify polymorphisms distributed across the genome. A phylogenetic tree constructed from aligned polymorphism alleles showed that 98.4% of the strains isolated from sick animals clustered in one clade (p<0.001), whereas strains isolated from healthy animals placed in multiple clades throughout the tree. These results show that M. haemolytica are genetically diverse, and that only a genetic subtype of M. haemolytica associates with disease. A test that differentiates M. haemolytica subtypes could potentially identify cattle carriers of strains that are genetically predisposed to cause respiratory disease. |