IV. INVESTIGATION OF C. DIPHTHERIAE
87
by agglutination with live cultures. Some of the heat-labile surface antigens
are type specific, others biotype specific and some even strain specific.
Their possible association with pathogenicity has not yet been clarified.
Branham et al. (1959) isolated from two graois strains an immunologically
active factor which in their opinion, caused swelling and oedema at the site
of infection. However, this has not been verified by others. Antibacterial
immunity has been demonstrated by several authors in different experimental models. Some of our latest field experiments (unpublished data)
have shown that in closed children’s communities there is a high percentage
of prolonged tox- diphtheria bacilli carriers 18-20 months after infection.
Due to the antibacterial immunity, a precipitous drop in the carrier rate
was to be observed thereafter without any application of vaccines or antibiotics. These facts were also confirmed in experimental models on guinea
pigs. Animals immunised with living tox- bacilli have shown a high
percentage of protection against a booster dose with toxf bacilli (Drilgoi
et ul., 1979). Hence, the conclusions are that antibacterial immunity seems
to act as a natural adjuvant for the antitoxic immunity.
Healthy tox- bacillus carriers, who have high antitoxin levels, should
not be treated by antibiotics.
It becomes evident that more investigations are still necessary to elucidate
some theoretical problems concerning the antigenic structure of C. diphtheriae.
In order to use the serological character for practical purposes, Calalb
et al. (1966, 1968) experimented with a polyvalent diphtherial antiserum
for slide agglutination. Due to its specificity, they proposed the technique
as a rapid means of identification in routine cultures of C. diphtheriue, but
spontaneous agglutination (15%) as well as the lack of agglutinability
(10%) limited the value of the method.
Recently, Ficiu and Maximescu (unpublished) improved the stability
and the rate of agglutinability by using as diluent a saline-buffered solution,
and by introducing in the polyvalent serum new monovalent sera. Using
the slide agglutination in the identification of more than 1500 corynebacteria they obtained high specificity, high rate of agglutinability of gravis
to& strains (98%) and an improved rate of positive reactions (87.3%).
These results which agree with those of Suslova (1964) recommend
slide agglutination for routine identification of C. diphtheriae.
V. PHAGE TYPING OF C. DIPHTHERIAE
A. General
The discovery of bacteriophages by Twort (1915) and d’HCrelle in 1917
and that of lysogeny by Bordet and Ciuc5 (1921a, b) opened new fields of
87
by agglutination with live cultures. Some of the heat-labile surface antigens
are type specific, others biotype specific and some even strain specific.
Their possible association with pathogenicity has not yet been clarified.
Branham et al. (1959) isolated from two graois strains an immunologically
active factor which in their opinion, caused swelling and oedema at the site
of infection. However, this has not been verified by others. Antibacterial
immunity has been demonstrated by several authors in different experimental models. Some of our latest field experiments (unpublished data)
have shown that in closed children’s communities there is a high percentage
of prolonged tox- diphtheria bacilli carriers 18-20 months after infection.
Due to the antibacterial immunity, a precipitous drop in the carrier rate
was to be observed thereafter without any application of vaccines or antibiotics. These facts were also confirmed in experimental models on guinea
pigs. Animals immunised with living tox- bacilli have shown a high
percentage of protection against a booster dose with toxf bacilli (Drilgoi
et ul., 1979). Hence, the conclusions are that antibacterial immunity seems
to act as a natural adjuvant for the antitoxic immunity.
Healthy tox- bacillus carriers, who have high antitoxin levels, should
not be treated by antibiotics.
It becomes evident that more investigations are still necessary to elucidate
some theoretical problems concerning the antigenic structure of C. diphtheriae.
In order to use the serological character for practical purposes, Calalb
et al. (1966, 1968) experimented with a polyvalent diphtherial antiserum
for slide agglutination. Due to its specificity, they proposed the technique
as a rapid means of identification in routine cultures of C. diphtheriue, but
spontaneous agglutination (15%) as well as the lack of agglutinability
(10%) limited the value of the method.
Recently, Ficiu and Maximescu (unpublished) improved the stability
and the rate of agglutinability by using as diluent a saline-buffered solution,
and by introducing in the polyvalent serum new monovalent sera. Using
the slide agglutination in the identification of more than 1500 corynebacteria they obtained high specificity, high rate of agglutinability of gravis
to& strains (98%) and an improved rate of positive reactions (87.3%).
These results which agree with those of Suslova (1964) recommend
slide agglutination for routine identification of C. diphtheriae.
V. PHAGE TYPING OF C. DIPHTHERIAE
A. General
The discovery of bacteriophages by Twort (1915) and d’HCrelle in 1917
and that of lysogeny by Bordet and Ciuc5 (1921a, b) opened new fields of