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Some Improved Versions of Methods for the Indirect Detection of Staphylococcal Protein A Gene Expressed in Escherichia coli
Author(s) -
Sakurada Junji,
Sumi Yoshiko
Publication year - 1992
Publication title -
microbiology and immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.664
H-Index - 70
eISSN - 1348-0421
pISSN - 0385-5600
DOI - 10.1111/j.1348-0421.1992.tb01640.x
Subject(s) - biology , escherichia coli , escherichia coli proteins , gene , bacterial protein , genetics , microbiology and biotechnology , computational biology
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.