title: A 39 kDa protein mediates adhesion of avian Pasteurella multocida to chicken embryo fibroblast cells.
abstract: To clarify the role of avian Pasteurella multocida capsule in pathogenesis, adhesion of capsulated strains P-1059, X-73 and Pm-18, and noncapsulated strains P-1059B, Pm-1 and Pm-3 to chicken embryo fibroblast (CEF) cells was compared. Number of adherent organisms of the capsulated strains to CEF cells were approximately three times as much as noncapsulated strains indicating that adhesive properties were enhanced by the presence of bacterial capsule. Pretreatments of the bacterial cells with heat, trypsin, or with antiserum caused a marked decrease in adhesion of capsulated strain P-1059 and its noncapsulated variant P-1059B. However, depolymerization of capsular hyaluronic acid with high dose of hyaluronidase enhanced adhesion of these strains. Combined treatments of the bacterial cells with both hyaluronidase and trypsin significantly (P < 0.05) inhibited the adherence of strain P-1059 as compared to the treatment only with trypsin, but strain P-1059B was not affected. SDS-PAGE profiles of crude capsular extract (CCE) prepared from capsulated strain P-1059 and its noncapsulated variant P-1059B grown on dextrose starch agar (DSA) plates by heating at 56 degrees C in a 2.5% NaCl solution demonstrated eight protein bands of 28, 34, 36, 39, 52, 56, 63 and 93 kDa. The 28, 34 and 36 kDa proteins were commonly major for both strains, and the 39 kDa protein was major only for strain P-1059 but poor in strain P-1059B. Outer membrane protein (OMP) profiles were identical with a major protein at 34 kDa and four minor proteins between the two strains. The adhesion of strain P-1059 and strain P-1059B to CEF cells was inhibited significantly (P < 0.01) by treatment with rabbit antisera against P-1059, P-1059B, CCE or 39 kDa protein of strain P-1059 as compared to the treatment with either PBS or with normal rabbit serum. These results indicated that an antigenic 39 kDa protein in the capsule may be responsible for adhesion of avian P. multocida type A strains to CEF cells as a virulence factor.
authors.affiliation: Department of Veterinary Microbiology, Nippon Veterinary and Animal Science University, Musashino, Tokyo 180-8602, Japan.
authors.forename: Entomack
authors.initials: E
authors.lastname: Borrathybay
authors.forename: Takuo
authors.initials: T
authors.lastname: Sawada
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Kataoka
authors.forename: Naoko
authors.initials: N
authors.lastname: Ohtsu
authors.forename: Masami
authors.initials: M
authors.lastname: Takagi
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Nakamura
authors.forename: Eiichi
authors.initials: E
authors.lastname: Kawamoto
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion / Q000187:drug effects; D016667:Bacterial Capsules / Q000737:chemistry / Q000502:physiology*; D001425:Bacterial Outer Membrane Proteins / Q000032:analysis; D001426:Bacterial Proteins / Q000032:analysis; D002642:Chick Embryo; D015169:Colony Count, Microbial; D004591:Electrophoresis, Polyacrylamide Gel / Q000662:veterinary; D005347:Fibroblasts / Q000382:microbiology*; D006820:Hyaluronic Acid / Q000494:pharmacology; D015151:Immunoblotting; D008970:Molecular Weight; D010326:Pasteurella Infections / Q000382:microbiology / Q000662:veterinary; D016979:Pasteurella multocida / Q000472:pathogenicity / Q000502:physiology*; D011201:Poultry Diseases / Q000382:microbiology; D014357:Trypsin / Q000494:pharmacology; D014774:Virulence
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D006820:Hyaluronic Acid; D014357:Trypsin