Journal Article

Detection and characterization of viruses as field and vaccine strains in feedlot cattle with bovine respiratory disease

Miles, D.G., Neill, J.D., Clement, T.J., Payton, M.E., d’Offay, J.M., Confer, A.W., Chase, C.C.L., Smith, R.A., Saliki, J.T., Landis, C., Ridpath, J.F., Fulton, R.W., Eberle, R., Burge, L.J.

2016

Overview

This study investigated viruses in bovine respiratory disease (BRD) cases in feedlots, including bovine herpesvirus-1 (BoHV-1), bovine viral diarrhea virus (BVDV), bovine respiratory syncytial virus (BRSV), bovine coronaviruses (BoCV) and parainfluenza-3 virus (PI3V). Nasal swabs were collected from 114 cattle on initial BRD treatment. Processing included modified live virus (MLV) vaccination. Seven BRD necropsy cases were included for 121 total cases. Mean number of days on feed before first sample was 14.9 days. Swabs and tissue homogenates were tested by gel based PCR (G-PCR), quantitative-PCR (qPCR) and quantitative real time reverse transcriptase PCR (qRT-PCR) and viral culture. There were 87/114 (76.3%) swabs positive for at least one virus by at least one test. All necropsy cases were positive for at least one virus. Of 121 cases, positives included 18/121 (14.9%) BoHV-1; 19/121 (15.7%) BVDV; 76/121 (62.8%) BoCV; 11/121 (9.1%) BRSV; and 10/121 (8.3%) PI3V. For nasal swabs, G-PCR (5 viruses) detected 44/114 (38.6%); q-PCR and qRT-PCR (4 viruses) detected 81/114 (71.6%); and virus isolation detected 40/114 (35.1%). Most were positive for only one or two tests, but not all three tests. Necropsy cases had positives: 5/7 G-PCR, 5/7 q-PCR and qRT-PCR, and all were positive by cell culture. In some cases, G-PCR and both real time PCR were negative for BoHV-1, BVDV, and PI3V in samples positive by culture. PCR did not differentiate field from vaccines strains of BoHV-1, BVDV, and PI3V. However based on sequencing and analysis, field and vaccine strains of culture positive BoHV-1, BoCV, BVDV, and PI3V, 11/18 (61.1%) of BoHV-1 isolates, 6/17 (35.3%) BVDV isolates, and 1/10 (10.0%) PI3V identified as vaccine. BRSV was only identified by PCR testing. Interpretation of laboratory tests is appropriate as molecular based tests and virus isolation cannot separate field from vaccine strains. Additional testing using sequencing appears appropriate for identifying vaccine strains.

• Publisher: Elsevier Ltd,Elsevier Limited
• Subject: Allergy and Immunology / Animal diseases / Animals / Bovine alphaherpesvirus 1 / Bovine herpesvirus 1 / Bovine orthopneumovirus / bovine respiratory disease / Bovine respiratory syncytial virus / Bovine respiratory viruses / Bovine viral diarrhea virus / Bovine viral diarrhea virus 1 / Cattle / Cattle Diseases - diagnosis / Cattle Diseases - virology / cell culture / Coronavirus, Bovine - isolation & purification / Diagnostic virology / Diarrhea Virus 1, Bovine Viral - isolation & purification / Feedlots / Flaviviridae / gels / Herpesviridae / Herpesvirus 1, Bovine - isolation & purification / Immunization / Laboratories / laboratory experimentation / Laboratory tests / microbial culture / MLV vaccines / necropsy / nose / Nose - virology / Parainfluenza Virus 3, Bovine - isolation & purification / Pneumonia / quantitative polymerase chain reaction / R&D / Real-Time Polymerase Chain Reaction - veterinary / Research & development / Respiratory diseases / Respiratory syncytial virus / Respiratory Syncytial Virus, Bovine - isolation & purification / Respiratory Tract Infections - veterinary / Respiratory Tract Infections - virology / reverse transcriptase polymerase chain reaction / sequence analysis / United States / vaccination / Vaccines / Vaccines, Attenuated / Veterinarians / Viral Vaccines / Viruses