title: Variability of Pasteurella multocida isolated from Icelandic sheep and detection of the toxA gene.
abstract: Pasteurella multocida can be part of the upper respiratory flora of animals, but under conditions of stress or immunocompromisation, the bacteria can cause severe respiratory symptoms. In this study, we compared 10 P. multocida isolates from Icelandic sheep with respiratory symptoms and 19 isolates from apparently healthy abattoir sheep. We examined capsule type, genetic variability and the presence of the toxA gene in the two groups. Surprisingly, we found that all ovine P. multocida isolates examined in this study carried the toxA gene, which markedly differs from what has been published from other studies. Interestingly, all isolates from abattoir animals were capsule type D, whilst bacteria isolated from animals with clinical respiratory symptoms had capsule type A, D or F. Examination of seven housekeeping genes indicated that the clinical respiratory isolates were significantly more heterogeneous than the abattoir isolates (P<0.05, two-tailed Mann-Whitney U test). The results suggest that there may be at least two groups of P. multocida in sheep - a genetically homogeneous group that resides in the respiratory tract and a genetically heterogeneous group that is the predominant cause of disease.
authors.affiliation: Institute for Experimental Pathology, University of Iceland, Keldur, Keldnavegur 3, 112 Reykjavik, Iceland.|BioMedical Center, University of Iceland, Reykjavík, Iceland.
authors.forename: Thorbjorg
authors.initials: T
authors.lastname: Einarsdottir
authors.affiliation: Institute for Experimental Pathology, University of Iceland, Keldur, Keldnavegur 3, 112 Reykjavik, Iceland.
authors.forename: Eggert
authors.initials: E
authors.lastname: Gunnarsson
authors.affiliation: Institute for Experimental Pathology, University of Iceland, Keldur, Keldnavegur 3, 112 Reykjavik, Iceland.|BioMedical Center, University of Iceland, Reykjavík, Iceland.
authors.forename: Olof G
authors.initials: OG
authors.lastname: Sigurdardottir
authors.affiliation: Institute for Experimental Pathology, University of Iceland, Keldur, Keldnavegur 3, 112 Reykjavik, Iceland.|BioMedical Center, University of Iceland, Reykjavík, Iceland.
authors.forename: Einar
authors.initials: E
authors.lastname: Jorundsson
authors.affiliation: Institute for Experimental Pathology, University of Iceland, Keldur, Keldnavegur 3, 112 Reykjavik, Iceland.
authors.forename: Vala
authors.initials: V
authors.lastname: Fridriksdottir
authors.affiliation: Veterinary Center, Dynskalar 30, 850 Hella, Iceland.
authors.forename: Gudridur E
authors.initials: GE
authors.lastname: Thorarinsdottir
authors.affiliation: Institute for Experimental Pathology, University of Iceland, Keldur, Keldnavegur 3, 112 Reykjavik, Iceland.
authors.forename: Sigridur
authors.initials: S
authors.lastname: Hjartardottir
mesh_terms: D000003:Abattoirs; D000818:Animals; D016667:Bacterial Capsules / Q000235:genetics; D001427:Bacterial Toxins / Q000235:genetics*; D002353:Carrier State / Q000453:epidemiology / Q000382:microbiology*; D020043:Genes, Essential; D014644:Genetic Variation; D005838:Genotype; D007055:Iceland / Q000453:epidemiology; D017720:Molecular Epidemiology; D060885:Multiplex Polymerase Chain Reaction; D010326:Pasteurella Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D016979:Pasteurella multocida / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D012137:Respiratory System / Q000382:microbiology; D012756:Sheep; D012757:Sheep Diseases / Q000453:epidemiology / Q000382:microbiology*
chemical_list: D001427:Bacterial Toxins; C052804:dermonecrotic toxin, Pasteurella multocida