184
T. BERGAN
Serogroup A, designated S. dysenteriae, contains ten serotypes including
Shiga’s and Schmitz’s bacilli as types 1 and 2. There is no common antigen
applicable to the whole group, but each type has a distinctive antigen.
There are a few minor cross-reactions within S. dysenteriae and between it
and members of the genus Escherichia. Serogroup A strains do not ferment
mannitol. Only serotype 1 produces the protein exotoxin associated with
dysentery (Shiga’s toxin), the main target of which is small blood vessels.
Cross-reactions have been described between S. dysenteriae serotype 1
and E. coli (Alkalescens-Dispar) 0: 1 ; S. dysenteriae type 2 and S. boydii 1
and 15; S. dysenteriae 8a, 8b and S. dysenteriae 8a, 8c; S. dysenteriae 8a,
8b and S. boydii 15; S. dysenteriae 10 and S. dysenteriae 2; S. boydii 1 and
E. coli (Alkalescens-Dispar) 0: 1 (Edwards and Ewing, 1972).
Serogroup B, S. jlexneri, consists of 13 serological entities with a number
of common antigens. Types X and Y have only the common group antigen.
Types 1-11 which lose their type antigen become types X or Y, but often
in a culture it is possible to find some colonies in X- or Y-suspect cultures
which have retained type antigen (Edwards and Ewing, 1972). Crossreactions to S. boydii and within S. jlexneri are many as shown in Table 66
of Edwards and Ewing (1972). S. jlexneri is mannitol fermenting.
Serogroup C, S. boydii, consists of strains which are referred to 15 established and two provisional distinct types with only few intraspecies
cross reactions, except types 10 and 11 which have strong cross-reactions,
but type 1 cross-reacts with types 4 and 11 ; type 4 with 1, 9, and 11 ; type
5 with 9; type 9 with 4, 5, and 13; type 10 with 11; type 11 with 1,4, and
10; and type 13 with 4 and 9.
Non-mannitol fermenting strains which do not possess the common
group antigens of S. jlexneri are referred to this species. The species
encompasses a few strains which utilize mannitol, but possess the S.
boydii antigens.
There are cross-reactions with S. dysenteriae, S. boydii and E. coli
(Alkalescens-Dispar) (see Table 71 of Edwards and Ewing (1972) and
Slopek and Metzger (1958)).
Serogroup D, for which the name S. sonnei is used, is serologically more
homogeneous than the other groups. S. sonnei has only one serotype, but
this varies between two states, phase I (S-form) and phase I1 (R-form)
(Edwards and Ewing, 1972; Rauss and Kontrohr, 1964) (Table 111).
Edwards and Ewing (1972) prefer to reserve the term phase for variation in
flagellar antigens and use the expressions form I and form 11. S. sonnei is
the only species within this genus which regularly is ONGP positive and
it ferments mannitol.
S. sonnei simultaneously with the change in phase also exhibits a change
from smooth colonies (S-form) in phase I and rough colonies (R-form) in
T. BERGAN
Serogroup A, designated S. dysenteriae, contains ten serotypes including
Shiga’s and Schmitz’s bacilli as types 1 and 2. There is no common antigen
applicable to the whole group, but each type has a distinctive antigen.
There are a few minor cross-reactions within S. dysenteriae and between it
and members of the genus Escherichia. Serogroup A strains do not ferment
mannitol. Only serotype 1 produces the protein exotoxin associated with
dysentery (Shiga’s toxin), the main target of which is small blood vessels.
Cross-reactions have been described between S. dysenteriae serotype 1
and E. coli (Alkalescens-Dispar) 0: 1 ; S. dysenteriae type 2 and S. boydii 1
and 15; S. dysenteriae 8a, 8b and S. dysenteriae 8a, 8c; S. dysenteriae 8a,
8b and S. boydii 15; S. dysenteriae 10 and S. dysenteriae 2; S. boydii 1 and
E. coli (Alkalescens-Dispar) 0: 1 (Edwards and Ewing, 1972).
Serogroup B, S. jlexneri, consists of 13 serological entities with a number
of common antigens. Types X and Y have only the common group antigen.
Types 1-11 which lose their type antigen become types X or Y, but often
in a culture it is possible to find some colonies in X- or Y-suspect cultures
which have retained type antigen (Edwards and Ewing, 1972). Crossreactions to S. boydii and within S. jlexneri are many as shown in Table 66
of Edwards and Ewing (1972). S. jlexneri is mannitol fermenting.
Serogroup C, S. boydii, consists of strains which are referred to 15 established and two provisional distinct types with only few intraspecies
cross reactions, except types 10 and 11 which have strong cross-reactions,
but type 1 cross-reacts with types 4 and 11 ; type 4 with 1, 9, and 11 ; type
5 with 9; type 9 with 4, 5, and 13; type 10 with 11; type 11 with 1,4, and
10; and type 13 with 4 and 9.
Non-mannitol fermenting strains which do not possess the common
group antigens of S. jlexneri are referred to this species. The species
encompasses a few strains which utilize mannitol, but possess the S.
boydii antigens.
There are cross-reactions with S. dysenteriae, S. boydii and E. coli
(Alkalescens-Dispar) (see Table 71 of Edwards and Ewing (1972) and
Slopek and Metzger (1958)).
Serogroup D, for which the name S. sonnei is used, is serologically more
homogeneous than the other groups. S. sonnei has only one serotype, but
this varies between two states, phase I (S-form) and phase I1 (R-form)
(Edwards and Ewing, 1972; Rauss and Kontrohr, 1964) (Table 111).
Edwards and Ewing (1972) prefer to reserve the term phase for variation in
flagellar antigens and use the expressions form I and form 11. S. sonnei is
the only species within this genus which regularly is ONGP positive and
it ferments mannitol.
S. sonnei simultaneously with the change in phase also exhibits a change
from smooth colonies (S-form) in phase I and rough colonies (R-form) in