title: Genetic diversity of Mycoplasma hyopneumoniae isolates of abattoir pigs.
abstract: Mycoplasma hyopneumoniae, the causative agent of porcine enzootic pneumonia, is present in swine herds worldwide. However, there is little information on strains infecting herds in Canada. A total of 160 swine lungs with lesions suggestive of enzootic pneumonia originating from 48 different farms were recovered from two slaughterhouses and submitted for gross pathology. The pneumonic lesion scores ranged from 2% to 84%. Eighty nine percent of the lungs (143/160) were positive for M. hyopneumoniae by real-time PCR whereas 10% (16/160) and 8.8% (14/160) were positive by PCR for M. hyorhinis and M. flocculare, respectively. By culture, only 6% of the samples were positive for M. hyopneumoniae (10/160). Among the selected M. hyopneumoniae-positive lungs (n=25), 9 lungs were co-infected with M. hyorhinis, 9 lungs with PCV2, 2 lungs with PRRSV, 12 lungs with S. suis and 10 lungs with P. multocida. MLVA and PCR-RFLP clustering of M. hyopneumoniae revealed that analyzed strains were distributed among three and five clusters respectively, regardless of severity of lesions, indicating that no cluster is associated with virulence. However, strains missing a specific MLVA locus showed significantly less severe lesions and lower numbers of bacteria. MLVA and PCR-RFLP analyses also showed a high diversity among field isolates of M. hyopneumoniae with a greater homogeneity within the same herd. Almost half of the field isolates presented less than 55% homology with selected vaccine and reference strains.
authors.affiliation: Groupe de recherche sur les maladies infectieuses du porc (GREMIP) and Centre de recherche en infectiologie porcine (CRIP), University of Montreal, Faculty of Veterinary Medicine, 3200 Sicotte Street, Saint-Hyacinthe, Quebec, Canada J2S 7C6.
authors.forename: Audrey
authors.initials: A
authors.lastname: Charlebois
authors.affiliation: Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail (ANSES), Laboratoire de Ploufragan-Plouzané, BP53, 22440 Ploufragan, France; Université Européenne de Bretagne, France.
authors.forename: Corinne
authors.initials: C
authors.lastname: Marois-Créhan
authors.affiliation: Department of Pathology and Microbiology, University of Montreal, Faculty of Veterinary Medicine, 3200 Sicotte Street, Saint-Hyacinthe, Quebec, Canada J2S 7C6.
authors.forename: Pierre
authors.initials: P
authors.lastname: Hélie
authors.affiliation: Groupe de recherche sur les maladies infectieuses du porc (GREMIP) and Centre de recherche en infectiologie porcine (CRIP), University of Montreal, Faculty of Veterinary Medicine, 3200 Sicotte Street, Saint-Hyacinthe, Quebec, Canada J2S 7C6.
authors.forename: Carl A
authors.initials: CA
authors.lastname: Gagnon
authors.affiliation: Groupe de recherche sur les maladies infectieuses du porc (GREMIP) and Centre de recherche en infectiologie porcine (CRIP), University of Montreal, Faculty of Veterinary Medicine, 3200 Sicotte Street, Saint-Hyacinthe, Quebec, Canada J2S 7C6.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Gottschalk
authors.affiliation: Groupe de recherche sur les maladies infectieuses du porc (GREMIP) and Centre de recherche en infectiologie porcine (CRIP), University of Montreal, Faculty of Veterinary Medicine, 3200 Sicotte Street, Saint-Hyacinthe, Quebec, Canada J2S 7C6. Electronic address: marie.archambault@umontreal.ca.
authors.forename: Marie
authors.initials: M
authors.lastname: Archambault
mesh_terms: D000003:Abattoirs; D000818:Animals; D002170:Canada; D060085:Coinfection / Q000382:microbiology / Q000662:veterinary; D014644:Genetic Variation; D008168:Lung / Q000382:microbiology / Q000473:pathology; D045705:Mycoplasma hyopneumoniae / Q000235:genetics* / Q000302:isolation & purification* / Q000472:pathogenicity; D010326:Pasteurella Infections / Q000662:veterinary; D016979:Pasteurella multocida / Q000302:isolation & purification; D045729:Pneumonia of Swine, Mycoplasmal / Q000382:microbiology* / Q000473:pathology; D019318:Porcine Reproductive and Respiratory Syndrome / Q000473:pathology; D019316:Porcine respiratory and reproductive syndrome virus / Q000302:isolation & purification; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D034421:Sus scrofa / Q000382:microbiology; D013552:Swine / Q000382:microbiology
keywords: Genotyping; MLVA; Mycoplasma hyopneumoniae; PCR-RFLP; Porcine enzootic pneumonia