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T. BERGAN
Goldhar and Eylan (1974) have demonstrated the chemical composition
of the cellular phage receptor sites.
C. Phage typing of S . f2exneri
1. Previous developments
A review of phage typing methods for S. jexneri has been presented by
Rische (1968b). In 1968, three typing sets were published (Meitert et al.,
1968; Milch et al., 1968; Slopek et al., 1968a, b, 1969). The set of Meitert
et al., was designed for only five S. jlexneri serotypes and two S. dysenteriae
types (vide supra), and consisted of 12 phages. Analogously, Istrati et al.
(1962) have presented a set of 13 phages for only S.JEexneri 2a. Other typing
sets have been published by Metzger et al. (1958), Istrati (1960a, b), Slopek
and Mulczyk (1961), Mulczyk and Slopek (1961), Istrati et al. (1964), and
Ldsz16 and Milch (1975).
2. International typing set
A number of phages from the above sets have been combined in a new
panel constituting the proposed international typing set for S. jlexneri
(Slopek, 1968). The selected phages and their homologous host-propagating
strains are shown in Table VII. Plaque morphology and viron morphology
are shown in Fig. 1.
3. Media (Slopek, 1973)
(a) Medium for phage propagation and growth of bacterial inocula before
typing
Peptone (Difco)
10 g
NaCl
3 g
N a 2 H P 0 4
2 g
Agar (Difco)
12 g
Distilled water to 1000 ml
p H 7.2 after sterilisation
For broth, this medium is used without agar.
(b) Phage typing medium
Peptone (Difco)
5 g
Meat extract
3 g
Lactose
10 g
Agar (Difco)
20 g
Bromocresol purple
0.025 g
Distilled water to 1000 ml
pH 6-8-7.0 after sterilisation