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AvxA, a composite serine-protease-RTX toxin of Avibacterium paragallinarum.
Journal article

AvxA, a composite serine-protease-RTX toxin of Avibacterium paragallinarum.

  • Küng E Institute of Veterinary Bacteriology, University of Bern, Bern, Switzerland.
  • Frey J
  • 2013-02-06
Published in:
  • Veterinary microbiology. - 2013
Animals
Antibodies, Bacterial
Bacterial Secretion Systems
Bacterial Toxins
Cattle
Cell Line
Chickens
Epitopes
Haemophilus Infections
Haemophilus paragallinarum
Operon
Recombinant Proteins
Serine Endopeptidases
Serine Proteases
English Avibacterium paragallinarum, the etiological agent of infectious coryza in chicken, was found to encode a bivalent serine-protease - RTX-porin toxin named AvxA. This toxin is encoded on a classical RTX operon structure with the activator gene avxC, the structural serin-protease-RTX toxin gene avxA, and the genes for a proper type I secretion system avxBD. AvxA is activated by the product of the avxC gene, secreted by the avxBD specified type I secretion system and proteolytically processed leaving a 95 kDa RTX moiety that is found in culture supernatants of A. paragallinarum serovars A, B and C. The RTX moiety of AvxA (AvxA-RTX) is cytotoxic against the avian macrophage like cell line HD11 but not against bovine macrophage cell line BoMac. Purified IgG from hyper-immune rabbit anti-AvxA-RTX serum made by immunization with recombinant AvxA-RTX from a serotype A strain fully neutralizes the cytotoxic activity of recombinant active AvxA-RTX and of A. paragallinarum serotypes A, B and C. This indicates that AvxA is a common major virulence attribute of all A. paragallinarum serotypes.
Language
  • English
Open access status
closed
Identifiers
Persistent URL
https://sonar.ch/global/documents/101849
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