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Courses:
Allied Health Microbiology
(BIO 280)
Research Interests: Surface Antigens of Group B Streptococci
Group B Streptococci (GBS) are pathogens of both
neonates and adults.
In neonates, GBS can cause meningitis, pneumonia, and sepsis. GBS can
also affect immunocompromised adults or adults with underlying
conditions such as diabetes, cancer, and alcoholism. Of the 9 known
serotypes of GBS, serotype III cause a substantial number of disease in
both neonates and adults.
Previous work has identified a surface antigen,
designated epsilon,
that is present on a more pathogenic subset of serotype III GBS. The
epsilon antigen is a glycoprotein with a di-serine (XS) motif
comprising two-thirds of the protein backbone. The gene encoding the
protein backbone has been designated srr-2 (serine-rich repeat
protein 2). The srr-2 gene is located in an locus with accesory
genes dedicated to the export of srr-2, such as secA2, secY2,
and others. Less pathogenic serotype III GBS and other serotypes have a
similar but different locus containing a different srr gene (srr-1).
I am interested in how srr-2 and the other
accessory
genes in this unique locus contribute to the increased pathogenicity of
this lineage. I am also interested in the carbohydrate modifications of
the Srr proteins. In addition, another surface antigen co-expressed
with epsilon on the surface of serotype III GBS has yet to be
characterized.
Selected
Publications:
Seifert, K.N., Adderson E.E., Whiting, A.A.,
Bohnsack, J.F., Crowley, P.J. and Brady, L.J. (2006) A unique
serine-rich repeat protein (Srr-2) and novel surface antigen (ε)
associated with a virulent lineage of serotype III Streptococcus agalactiae.
Microbiology 152: 1029-1040.
Seifert, K.N., McArthur, W.P., Bleiweis, A.S., and
Brady, L.J. (2003)
Characterization of group B streptococcal glyceraldehyde 3-phosphate
dehydrogenase: surface localization, enzymatic activity, and
protein-protein interactions. Canadian Journal of Microbiology. 49:
350-356.
Dorn, B.R., Burks, J.N., Seifert, K.N., and
Progulske-Fox, A. (2000) Invasion of endothelial and epithelial cells
by strains of Porphyromonas gingivalis. FEMS Microbiology
Letters. 187: 139-144.
Munce, T., Seifert, K., and Spencer, C.N. 1998.
Comparative energy flow
to the fish community in a prairie system and a forested stream using
growth rate and stable isotope analysis. Proc. S.D. Acad. Sci.
77:29-40.
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