Some improved versions of methods for the indirect detection of staphylococcal protein A gene expressed in Escherichia coli.
Several versions of methods for the indirect detection of expression of staphylococcal protein A gene (spa) in Escherichia coli (E. coli) were devised by making use of biological properties of staphylococcal protein A (SpA). i) Hemagglutination of sheep red blood cells (SRBC) sensitized with anti-SRBC-antibodies using heat-treated spa-transformed E. coli organisms; Native spa-transformed E. coli organisms did not agglutinate the sensitized SRBC. The heat-treatment (60 C, 4 hr) of the transformants, however, caused positive hemagglutination like SpA-positive Staphylococcus aureus (S. aureus) organisms. ii) Halo formation around colonies on agar plates containing normal dog serum, which is originally used for the detection of SpA of S. aureus. A mutant strain NMJ was isolated, which showed formation of the halo of precipitate due to interaction between immunoglobulin and SpA. iii) A new version of immunodetection; After lysis of the transformants grown on a nitrocellulose membrane by alkali, SpA could be directly detected by immuno-detection procedures after inactivation of endogenous peroxidase in bacteria by phenylhydrazine and hydrogen peroxide.
Sakurada
J
J
Department of Bacteriology, Jikei University School of Medicine, Tokyo, Japan.
Sumi
Y
Y
D004926:Escherichia coli / Q000737:chemistry*; D005798:Genes, Bacterial / Q000235:genetics; D006386:Hemagglutination Tests; D011994:Recombinant Proteins / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics; D013205:Staphylococcal Protein A / Q000032:analysis* / Q000096:biosynthesis / Q000235:genetics
D011994:Recombinant Proteins; D013205:Staphylococcal Protein A