title: A novel quantitative real-time polymerase chain reaction method for detecting toxigenic Pasteurella multocida in nasal swabs from swine.
abstract: BACKGROUND
  Progressive atrophic rhinitis (PAR) in pigs is caused by toxigenic Pasteurella multocida. In Switzerland, PAR is monitored by selective culture of nasal swabs and subsequent polymerase chain reaction (PCR) screening of bacterial colonies for the P. multocida toxA gene. A panel of 203 nasal swabs from a recent PAR outbreak were used to evaluate a novel quantitative real-time PCR for toxigenic P. multocida in porcine nasal swabs.
  
  
  RESULTS
  In comparison to the conventional PCR with a limit of detection of 100 genome equivalents per PCR reaction, the real-time PCR had a limit of detection of 10 genome equivalents. The real-time PCR detected toxA-positive P. multocida in 101 samples (49.8%), whereas the conventional PCR was less sensitive with 90 toxA-positive samples (44.3%). In comparison to the real-time PCR, 5.4% of the toxA-positive samples revealed unevaluable results by conventional PCR.
  
  
  CONCLUSIONS
  The approach of culture-coupled toxA PCR for the monitoring of PAR in pigs is substantially improved by a novel quantitative real-time PCR.
authors.affiliation: Vetsuisse Faculty, Institute of Veterinary Bacteriology, University of Zurich, Winterthurerstrasse 270, 8057, Zurich, Switzerland. simone.scherrer@vetbakt.uzh.ch.
authors.forename: Simone
authors.identifier: http://orcid.org/0000-0001-9548-8798
authors.initials: S
authors.lastname: Scherrer
authors.affiliation: Vetsuisse Faculty, Institute of Veterinary Bacteriology, University of Zurich, Winterthurerstrasse 270, 8057, Zurich, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Frei
authors.affiliation: Vetsuisse Faculty, Institute of Veterinary Bacteriology, University of Zurich, Winterthurerstrasse 270, 8057, Zurich, Switzerland.
authors.forename: Max Michael
authors.initials: MM
authors.lastname: Wittenbrink
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000235:genetics; D057230:Limit of Detection; D009297:Nasal Mucosa / Q000382:microbiology; D010326:Pasteurella Infections / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary*; D016979:Pasteurella multocida / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction / Q000592:standards / Q000662:veterinary*; D013552:Swine; D013553:Swine Diseases / Q000175:diagnosis* / Q000382:microbiology
chemical_list: D001427:Bacterial Toxins
keywords: Pasteurella multocida; Pig; Progressive atrophic rhinitis; Quantitative real-time PCR; toxA gene