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Studies of interactions with Streptococcus equi and the host

extracellular proteins of Streptococcus equi subspec. equi and Streptococcus equi subspec. zooepidemicus

Hulting, Greta (2016). Studies of interactions with Streptococcus equi and the host. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 ; 2016:64
ISBN 978-91-576-8630-5
eISBN 978-91-576-8631-2
[Doctoral thesis]

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Streptococcus equi subspecies equi (S. equi) causes strangles, a highly contagious and serious disease in the upper respiratory tract of horses, with a worldwide distribution. Streptococcus equi subspecies zooepidemicus (S. zooepidemicus) is regarded as an opportunistic pathogen infecting horses and other animals, and is believed to be the ancestor of S. equi. Pathogenic bacteria have evolved excellent ways of escaping the immune system and other defence mechanisms or have adapted to efficiently colonise specific areas of the host.

The overall objective of this thesis was to study the interaction between S. equi and S. zooepidemicus and the host. An important feature for establishment of an infection and survival of the microorganism inside the host is the interaction with, and adherence to, host tissues. In one of the studies, a group of extracellular proteins with sequence similarities with the fibronectin- and collagen-binding protein FNE, were identified and characterised. All of the proteins bound to collagen to different degrees, and one of the proteins, FNEE, was shown to bind both collagen and fibronectin, and mediate a collagen contraction in presence of PDGF-BB. In another study, an additional IgG endopeptidase of S. equi (and S. zooepidemicus), called IdeE2 (IdeZ2) was described. IdeE2 efficiently degrades horse IgG4, and together with another endopeptidase, this enzyme induced protection in a mouse infection model. In a continuation of the IdeE2/IdeZ2 study, on screening a panel of S. zooepidemicus isolates, sequence variation within the ideZ2 gene was discovered, resulting in three major gene variations. However, the variation in this gene did not reflect the origin of the isolates or the MLST group of the strain. Extended computer alignment with IdeS from S. pyogenes, revealed similarities to structures known to be important for endopeptidase activity. The recombinant proteins IdeZ212, IdeZ216 and IdeZ221 all degraded horse IgG highly efficient despite amino acid differences in between the proteins, which argues for the importance of these proteins in the infection process.

Authors/Creators:Hulting, Greta
Title:Studies of interactions with Streptococcus equi and the host
Subtitle:extracellular proteins of Streptococcus equi subspec. equi and Streptococcus equi subspec. zooepidemicus
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :25 May 2016
Depositing date:25 May 2016
Number of Pages:53
IHulting, G., Flock, M., Frykberg, L., Lannergård, J., Flock, J-I. and Guss, B. (2009). Two novel IgG endopeptidases of Streptococcus equi. FEMS Microbiology Letters 298, 44-50.
IILannergård, J., Hulting, G., Reyhani, V., Copperfeldt, H., Löfgren, M., Hörnaeus, K., Rubin, K. and Guss, B. A family of fibronectin binding and collagen binding proteins of Streptococcus equi subspecies equi (manuscript).
IIIHulting, G., Sandgren, M., Robinson, C., Waller, A., Steward, K. and Guss, B. The IgG endopeptidase IdeZ2 of Streptococcus equi subspecies zooepidemicus displays sequence variation (manuscript).
Place of Publication:Uppsala
Publisher:Department of Microbiology, Swedish University of Agricultural Sciences
ISBN for printed version:978-91-576-8630-5
ISBN for electronic version:978-91-576-8631-2
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:L Animal production > L50 Animal physiology and biochemistry
L Animal production > L73 Animal diseases
Subjects:(A) Swedish standard research categories 2011 > 1 Natural sciences > 106 Biological Sciences (Medical to be 3 and Agricultural to be 4) > Microbiology (Microbiology in the medical area to be 30109)
(A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 403 Veterinary Science > Pathobiology
Agrovoc terms:horses, streptococcus equi, streptococcus zooepidemicus, strangles, respiratory diseases, pathogens, proteins, collagen, peptidases, genetic variation
Keywords:Strangles, IgG-endopeptidases, FNE-like proteins
Permanent URL:
ID Code:13408
Faculty:NJ - Fakulteten för naturresurser och jordbruksvetenskap
Department:(NL, NJ) > Dept. of Microbiology (until 161231)
External funders:FORMAS
Deposited By: Greta Hulting
Deposited On:26 May 2016 05:52
Metadata Last Modified:10 Sep 2020 13:41

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