Open AccessAnalysis of immunoglobulin G-binding-protein expression by invasive isolates of Streptococcus pyogenes
Author(s) -
Roberta Raeder,
M D Boyle
Publication year - 1995
Publication title -
clinical and diagnostic laboratory immunology
Language(s) - English
Resource type - Journals
eISSN - 1098-6588
pISSN - 1071-412X
DOI - 10.1128/cdli.2.4.484-486.1995
Subject(s) - serotype , streptococcus pyogenes , antiserum , antibody , biology , immunoglobulin g , microbiology and biotechnology , myeloma protein , group a , fibrinogen , immunology , medicine , bacteria , biochemistry , genetics , staphylococcus aureus
Invasive group A streptococcal isolates collected as part of a Centers for Disease Control and Prevention surveillance study were analyzed for expression of immunoglobulin G (IgG)-binding proteins. Two IgG-binding phenotypes of group A isolates of the M1 serotype were identified. The first group expressed a surface protein that bound all four human IgG subclasses (type IIo) and was recognized by rabbit anti-serotype M1-specific antiserum but not by normal rabbit serum. The second group expressed an IgG-binding protein that was also recognized by the anti-serotype M1 antiserum but demonstrated significant nonimmune reactivity only with human IgG3 (type IIb). Analysis of extracts of the isolates for reactivity with human IgA, fibrinogen, and albumin was also performed. The importance of the binding of human plasma proteins to pathogenic group A streptococci remains to be established.