214
T. BERGAN
as much as 54% of the bacterial isolates (type 15: 18.7%; and type 43:
34.8%) (Slopek, 1973). Another eight types contributed 34.6% of the
strains. The results will vary according to local variation of dominating
types. The phage type frequencies of Slopek (1973) are compared in Table
XI with the results of LBsz16 et al. (1973a, b).
An example of the distribution of phage types between bacterial serotypes is shown in Table XII.
D. Phage typing of S. boydii
Bercovici et al. (1967, 1972) have been concerned with phage typing of
S . boydii. Bercovici et al. (1972) ultimately used 20 phages which were
either
(1) from residual waters and adapted to reference strains of S. boydii,
(2) from Salmonella typhimurium, but also active on S . boydii,
(3) from E. coli adapted to S . boydii, or
(4) from S. dysenteriae, serotype 2 and adapted to S. boydii.
The phages were designated 1, 2, 3, 4, 6, 7, 8, 9, 10, 13, 14, 18, 68, 100,
204, 210, 338, 390, and 394.
The preparation of plates followed the procedure outlined for S . jexneri
(Section VI . C, 6, this Chapter). Three-hour cultures (37°C in 0.8%
Nutrient Broth (Difco)) were used to inoculated plates with Nutrient
Broth (Difco)) and 2% agar.
The plates were read after 16-18 h at 37°C and lytic patterns recorded
according to the key in Table XIII. Among the 35 different lysotypes, the
dominating one contributed some 3574, and four other types were responsible for some 576 of the isolates.
When standardized laboratory techniques are used, S. boydii phage
types appear stable, as evidenced by serial isolates from the same individuals
and by the patterns of strains derived from two particular epidemic outbreaks (Bercovici et al., 1972). The patterns also have remained stable
after storage of the bacteria in vitro for six to seven months.
E. Phage typing of S. sonnei
1. Previous developments
Due to the s-rological homogeneity of S . smzei, phage typing is important for the subdivision of this species. Earlier phage typing methods for
this species have been reviewed by Rische (1968).
The first published lysotyping scheme for S . sonnei was developed by
Hammarstrom (1947, 1949) during the years 1943-1947. At that time, S .
T. BERGAN
as much as 54% of the bacterial isolates (type 15: 18.7%; and type 43:
34.8%) (Slopek, 1973). Another eight types contributed 34.6% of the
strains. The results will vary according to local variation of dominating
types. The phage type frequencies of Slopek (1973) are compared in Table
XI with the results of LBsz16 et al. (1973a, b).
An example of the distribution of phage types between bacterial serotypes is shown in Table XII.
D. Phage typing of S. boydii
Bercovici et al. (1967, 1972) have been concerned with phage typing of
S . boydii. Bercovici et al. (1972) ultimately used 20 phages which were
either
(1) from residual waters and adapted to reference strains of S. boydii,
(2) from Salmonella typhimurium, but also active on S . boydii,
(3) from E. coli adapted to S . boydii, or
(4) from S. dysenteriae, serotype 2 and adapted to S. boydii.
The phages were designated 1, 2, 3, 4, 6, 7, 8, 9, 10, 13, 14, 18, 68, 100,
204, 210, 338, 390, and 394.
The preparation of plates followed the procedure outlined for S . jexneri
(Section VI . C, 6, this Chapter). Three-hour cultures (37°C in 0.8%
Nutrient Broth (Difco)) were used to inoculated plates with Nutrient
Broth (Difco)) and 2% agar.
The plates were read after 16-18 h at 37°C and lytic patterns recorded
according to the key in Table XIII. Among the 35 different lysotypes, the
dominating one contributed some 3574, and four other types were responsible for some 576 of the isolates.
When standardized laboratory techniques are used, S. boydii phage
types appear stable, as evidenced by serial isolates from the same individuals
and by the patterns of strains derived from two particular epidemic outbreaks (Bercovici et al., 1972). The patterns also have remained stable
after storage of the bacteria in vitro for six to seven months.
E. Phage typing of S. sonnei
1. Previous developments
Due to the s-rological homogeneity of S . smzei, phage typing is important for the subdivision of this species. Earlier phage typing methods for
this species have been reviewed by Rische (1968).
The first published lysotyping scheme for S . sonnei was developed by
Hammarstrom (1947, 1949) during the years 1943-1947. At that time, S .