314
M. A. GERENCSER
were higher with trypsin treated walls and more cross-reactions were
demonstrated with these antigens. Pronase treatment lowered homologous
titres and removed some of the cross-reactions.
B. Detection of soluble antigens
Immunodiffusion tests (ID) using acetone precipitated culture medium
supernatant antigens were first described by King and Meyer (1963). Like
FA, serological groupings obtained by I D tests paralleled species identification by other methods so that this test can be used for identification.
In general, I D is about equal to FA in sensitivity but is less species specific
(Lambert et al., 1967). The number of precipitation lines produced in
homologous systems and the degree of cross-reaction between different
organisms is highly variable. This is due to lack of standardisation of the
antigen content of the crude culture medium antigens and to variability
between different lots of antiserum (Slack et al., 1969; Bowden and Hardie,
1973; Slack and Gerencser, 1975; Bowden et al., 1976).
Bowden and Hardie (1973) and Bowden et al. (1976) found that pronasetreated autoclaved extracts of whole cells were useful for serological
identification of A . israelii serotypes 1 and 2, A . naeslundii, and A . viscosus
serotype 2. These antigens were used in capillary tube or gel precipitin
tests with antisera known to react with cell wall carbohydrate antigens.
The antisera were prepared by injecting rabbits with heat-treated whole
cells in combination with Freund’s complete adjuvant. The precipitin
tests distinguished between the three species and confirmed the strong
cross-reaction between A . naeslundii and A . siscosus serotype 2.
Holmberg et al. (1975a, b) performed a detailed analysis of cytoplasmic
antigens of A . israelii and developed a standard antigen-antibody system
for use with crossed immunoelectrophoresis (CIE). They used two
standard antisera, one containing pooled antiserum to whole cells of
A. israelii and one with pooled antiserum to cell lysates. The standard
antigen was a pool of sonic lysates prepared from six strains of A. israelii.
With this system ten cytoplasmic antigens were found in A . israelii. When
single strains were tested by CIE, cytoplasmic antigens from type 1 strains
had at least five individual antigens and some strains had all ten. Serotype
2 strains contained up to six of the individual antigens. Using CIE and an
intermediate gel, antiserum from other species of Actinomyces, Arachnia,
Propionibacterium and several fungi were tested against the standard A.
israelii antigen. The cytoplasmic antigens prepared by sonication were
species specific and did not react with any of the heterologous antisera
tested. Common antigens between A . israelii and both A . naeslundii and
P. acnes were found in cytoplasmic antigens prepared by other extraction
procedures,
M. A. GERENCSER
were higher with trypsin treated walls and more cross-reactions were
demonstrated with these antigens. Pronase treatment lowered homologous
titres and removed some of the cross-reactions.
B. Detection of soluble antigens
Immunodiffusion tests (ID) using acetone precipitated culture medium
supernatant antigens were first described by King and Meyer (1963). Like
FA, serological groupings obtained by I D tests paralleled species identification by other methods so that this test can be used for identification.
In general, I D is about equal to FA in sensitivity but is less species specific
(Lambert et al., 1967). The number of precipitation lines produced in
homologous systems and the degree of cross-reaction between different
organisms is highly variable. This is due to lack of standardisation of the
antigen content of the crude culture medium antigens and to variability
between different lots of antiserum (Slack et al., 1969; Bowden and Hardie,
1973; Slack and Gerencser, 1975; Bowden et al., 1976).
Bowden and Hardie (1973) and Bowden et al. (1976) found that pronasetreated autoclaved extracts of whole cells were useful for serological
identification of A . israelii serotypes 1 and 2, A . naeslundii, and A . viscosus
serotype 2. These antigens were used in capillary tube or gel precipitin
tests with antisera known to react with cell wall carbohydrate antigens.
The antisera were prepared by injecting rabbits with heat-treated whole
cells in combination with Freund’s complete adjuvant. The precipitin
tests distinguished between the three species and confirmed the strong
cross-reaction between A . naeslundii and A . siscosus serotype 2.
Holmberg et al. (1975a, b) performed a detailed analysis of cytoplasmic
antigens of A . israelii and developed a standard antigen-antibody system
for use with crossed immunoelectrophoresis (CIE). They used two
standard antisera, one containing pooled antiserum to whole cells of
A. israelii and one with pooled antiserum to cell lysates. The standard
antigen was a pool of sonic lysates prepared from six strains of A. israelii.
With this system ten cytoplasmic antigens were found in A . israelii. When
single strains were tested by CIE, cytoplasmic antigens from type 1 strains
had at least five individual antigens and some strains had all ten. Serotype
2 strains contained up to six of the individual antigens. Using CIE and an
intermediate gel, antiserum from other species of Actinomyces, Arachnia,
Propionibacterium and several fungi were tested against the standard A.
israelii antigen. The cytoplasmic antigens prepared by sonication were
species specific and did not react with any of the heterologous antisera
tested. Common antigens between A . israelii and both A . naeslundii and
P. acnes were found in cytoplasmic antigens prepared by other extraction
procedures,