title: Investigation of polymerase chain reaction assays to improve detection of bacterial involvement in bovine respiratory disease.
abstract: Bovine respiratory disease (BRD) causes severe economic losses to the cattle farming industry worldwide. The major bacterial organisms contributing to the BRD complex are Mannheimia haemolytica, Histophilus somni, Mycoplasma bovis, Pasteurella multocida, and Trueperella pyogenes. The postmortem detection of these organisms in pneumonic lung tissue is generally conducted using standard culture-based techniques where the presence of therapeutic antibiotics in the tissue can inhibit bacterial isolation. In the current study, conventional and real-time polymerase chain reaction (PCR) assays were used to assess the prevalence of these 5 organisms in grossly pneumonic lung samples from 150 animals submitted for postmortem examination, and the results were compared with those obtained using culture techniques. Mannheimia haemolytica was detected in 51 cases (34%) by PCR and in 33 cases (22%) by culture, H. somni was detected in 35 cases (23.3%) by PCR and in 6 cases (4%) by culture, Myc. bovis was detected in 53 cases (35.3%) by PCR and in 29 cases (19.3%) by culture, P. multocida was detected in 50 cases (33.3%) by PCR and in 31 cases (20.7%) by culture, and T. pyogenes was detected in 42 cases (28%) by PCR and in 31 cases (20.7%) by culture, with all differences being statistically significant. The PCR assays indicated positive results for 111 cases (74%) whereas 82 cases (54.6%) were culture positive. The PCR assays have demonstrated a significantly higher rate of detection of all 5 organisms in cases of pneumonia in cattle in Northern Ireland than was detected by current standard procedures.
authors.affiliation: Agri-Food and Biosciences Institute, Veterinary Sciences Division, Stormont, Belfast, Northern Ireland colin.bell@afbini.gov.uk.
authors.forename: Colin J
authors.initials: CJ
authors.lastname: Bell
authors.affiliation: Agri-Food and Biosciences Institute, Veterinary Sciences Division, Stormont, Belfast, Northern Ireland.
authors.forename: Paul
authors.initials: P
authors.lastname: Blackburn
authors.affiliation: Agri-Food and Biosciences Institute, Veterinary Sciences Division, Stormont, Belfast, Northern Ireland.
authors.forename: Mark
authors.initials: M
authors.lastname: Elliott
authors.affiliation: Agri-Food and Biosciences Institute, Veterinary Sciences Division, Stormont, Belfast, Northern Ireland.
authors.forename: Tony I A P
authors.initials: TI
authors.lastname: Patterson
authors.affiliation: Agri-Food and Biosciences Institute, Veterinary Sciences Division, Stormont, Belfast, Northern Ireland.
authors.forename: Sean
authors.initials: S
authors.lastname: Ellison
authors.affiliation: Agri-Food and Biosciences Institute, Veterinary Sciences Division, Stormont, Belfast, Northern Ireland.
authors.forename: Angela
authors.initials: A
authors.lastname: Lahuerta-Marin
authors.affiliation: Agri-Food and Biosciences Institute, Veterinary Sciences Division, Stormont, Belfast, Northern Ireland.
authors.forename: Hywel J
authors.initials: HJ
authors.lastname: Ball
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001419:Bacteria / Q000145:classification / Q000302:isolation & purification*; D001431:Bacteriological Techniques / Q000662:veterinary*; D048090:Bovine Respiratory Disease Complex / Q000175:diagnosis* / Q000453:epidemiology; D002417:Cattle; D009660:Northern Ireland / Q000453:epidemiology; D011014:Pneumonia / Q000662:veterinary; D016133:Polymerase Chain Reaction / Q000379:methods / Q000662:veterinary*
chemical_list: D000900:Anti-Bacterial Agents
keywords: Bovine respiratory disease; culture; polymerase chain reaction