Mapping the Fibrinogen-Binding Domain of Serum Opacity Factor of Group A Streptococci

2002 ◽  
Vol 44 (4) ◽  
pp. 236-240 ◽  
Author(s):  
Harry S. Courtney ◽  
James B. Dale ◽  
David L. Hasty
Keyword(s):  
Binding Domain ◽  
Group A Streptococci ◽  
Fibrinogen Binding ◽  
Serum Opacity Factor ◽  
Group A

scholarly journals Serum Opacity Factor (SOF) of Streptococcus pyogenes Evokes Antibodies That Opsonize Homologous and Heterologous SOF-Positive Serotypes of Group A Streptococci

2003 ◽  
Vol 71 (9) ◽  
pp. 5097-5103 ◽  
Author(s):  
Harry S. Courtney ◽  
David L. Hasty ◽  
James B. Dale
Keyword(s):  
Streptococcus Pyogenes ◽  
Rabbit Antiserum ◽  
M Protein ◽  
Group A Streptococci ◽  
Streptococcal Infections ◽  
Vaccine Candidates ◽  
Human Antibodies ◽  
Serum Opacity Factor ◽  
Group A

ABSTRACT Serum opacity factor (SOF) is a protein expressed by Streptococcus pyogenes that opacifies mammalian serum. SOF is also a virulence factor of S. pyogenes, but it has not been previously shown to elicit a protective immune response. Herein, we report that SOF evokes bactericidal antibodies against S. pyogenes in humans, rabbits, and mice. Rabbit antiserum against purified recombinant SOF2 opsonized SOF-positive M type 2, 4, and 28 S. pyogenes in human blood but had no effect on SOF-negative M type 5 S. pyogenes. Furthermore, affinity-purified human antibodies against SOF2 also opsonized SOF-positive streptococci. A combination of antisera against M2 and SOF2 proteins was dramatically more effective in killing streptococci than either antiserum alone, indicating that antibodies against SOF2 enhance the opsonic efficiency of M protein antibodies. Mice tolerated an intravenous injection of 100 μg of SOF without overt signs of toxicity, and immunization with SOF protected mice against challenge infections with M type 2 S. pyogenes. These data indicate that SOF evokes opsonic antibodies that may protect against infections by SOF-positive serotypes of group A streptococci and suggest that different serotypes of SOF have common epitopes that may be useful vaccine candidates to protect against group A streptococcal infections.

scholarly journals Characterization of group A streptococci (Streptococcus pyogenes): correlation of M-protein and emm-gene type with T-protein agglutination pattern and serum opacity factor

2006 ◽  
Vol 55 (2) ◽  
pp. 157-164 ◽  
Author(s):  
Dwight R. Johnson ◽  
Edward L. Kaplan ◽  
Amy VanGheem ◽  
Richard R. Facklam ◽  
Bernard Beall
Keyword(s):  
M Protein ◽  
Supplementary Information ◽  
Group A Streptococci ◽  
University Of Minnesota ◽  
Gene Encoding ◽  
Strain Characterization ◽  
Serum Opacity Factor ◽  
Invasive Infections ◽  
Group A

Strain characterization of group A streptococci (GAS) has traditionally been based on serological identification of M protein. Additional tests to determine T-protein serotype and production of streptococcal serum opacity factor (SOF) provide important information both to aid in and to supplement M-protein serotyping. Advances in DNA-sequencing technology in the late twentieth century resulted in the development of a method for determining the M type of GAS from the sequence of the gene encoding M protein, the emm gene. Although emm-sequence typing has largely replaced M typing in many laboratories, information provided by T typing and SOF determination continues to provide valuable supplementary information for strain characterization. A comprehensive summary of the correlation of T pattern and SOF production with M type was last published in 1993, several years before emm typing became widely available. Since then, the ease of M-type identification afforded by emm typing has resulted in an increase in the number of confirmed M/emm types of more than 50 %. However, comprehensive information about T-protein serotype and the correlation of SOF production with these new M/emm types is not widely available. This report presents a comprehensive summary of this information, not only for newly described types, but also updated information for previously described types. This information was extracted from combined records from streptococcal reference laboratories at the University of Minnesota and at the Centers for Disease Control and Prevention in Atlanta. Data from more than 40 000 strains (representing uncomplicated GAS infections, systemic invasive infections and strains associated with non-suppurative sequelae, collected from the US and diverse locations worldwide) were analysed.

scholarly journals Why type streptococci? The epidemiology of group A streptococci in Oxfordshire 1976–1980

1982 ◽  
Vol 88 (3) ◽  
pp. 439-452 ◽  
Author(s):  
R. T. Mayon-White ◽  
Elizabeth M. Perks
Keyword(s):  
General Practice ◽  
Tetracycline Resistance ◽  
Great Majority ◽  
Skin Lesions ◽  
Group A Streptococci ◽  
Pattern Type ◽  
Stable Pattern ◽  
Special Groups ◽  
Serum Opacity Factor ◽  
Group A

SummaryThe results of typing all group A streptococci isolated in one laboratory in 5 years were reviewed to see if the collected information showed epidemiological patterns. The great majority of the 5858 streptococci typed came from patients seen in general practice: 72% from throat swabs and 11 % from skin lesions. Eight types, M types 1, 2, 3, 4, 6, 12, 22 and type 28 R accounted for 65% of strains. These eight types had different patterns: types 2 and 6 caused small circumscribed outbreaks and were uncommon between epidemics; types 3, 4 and 12 caused larger, wider epidemics, whereas types 1, 22 and 28 R had a more stable pattern. Type 4 was more commonly resistant to tetracycline than most other types, a finding which affected the apparent incidence of tetracycline resistance in group A streptococci. Streptococci from superficial sites were more likely to have serum opacity factor and to lack a detectable M-antigen than strains isolated from the throat. Routine typing of streptococci helped to detect outbreaks of infection in special groups. It is concluded that regular streptococcal typing should be continued in some places.

scholarly journals Susceptibility of chicken embryos to group A streptococci: Correlation with fibrinogen binding

1993 ◽  
Vol 7 (3) ◽  
pp. 231-240 ◽  
Author(s):  
Karl-Hermann Schmidt ◽  
Joachim Wiesner ◽  
Dieter Gerlach ◽  
Werner Reichardt ◽  
J�rg-Hermann Ozegowski ◽  
...  
Keyword(s):  
Group A Streptococci ◽  
Chicken Embryos ◽  
Fibrinogen Binding ◽  
Group A
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