V. BACTERIOPHAGE TYPING OF SHIGELLA
191
There was no relationship between antigenic type of the phages and their
lytic spectra.
C. Phage sensitivity to physical agents
Phage sensitivity to physical agents generally varies with the p H and
type of suspension medium. Dilute phage suspensions of S. sonneiare
rapidly inactivated, whereas concentrated suspensions with 109-10 11
phages/ml keep for years at + 4°C. A suitable p H for survival appears to be
7.2 (ZieschC and Rische, 1973).
VI. METHOD O F PHAGE TYPING
A. Development of lysotyping
Polyvalent Shigella phages were used early diagnostically to differentiate
Shigella from other enterobacteria (Marcuse, 1931 ; Massa, 1931 ; Sartorius,
1932; Sartorius and Reploh, 1931 ; Sonnenschein, 1925a, b ; Thomen and
Frobisher, 1945). Although the phages are mainly restricted in their action
to shigellae, they may also lyse some E . coli, Enterobacter aerogenoides, E .
cloacae, Salmonella, Arizona, S. dysenteriae, S. jexneri, and Proteus
(Grunow, 1965~). Shigella phages have not lysed Citrobacter or Klebsiella.
Conversely, Shigella has been resistant to even avid phages from Alcalescens,
Proteus, Salmonella, and Aeromonas shigelloides (Rische et al., 1969).
Another interesting diagnostic aspect is the isolation of phage from faeces
to indicate Shigella colonisation of the gut (Hammarstrom, 1949; Grunow
and Kohler, 1965; Wheeler and Burgdorf, 1941).
Phage typing sets have evolved gradually since the early work of Burnet
and McKie (1930) who were the first to demonstrate the fact that phages
produced different lysotypes in Shigella. Burnet in 1933 developed a
typing set for S. jexneri.
Since phages are mostly lytic only for one serogroup, phage typing sets
are specialised for each species in the genus. Methodology is roughly the
same for each species, but there are small, probably coincidental, differences
in recommended techniques for each set. Accordingly, even though they
may work for all sets, the techniques for each one will be described separately.
B. Phage typing of S. dysenteriae
The phages of S. dysenteriae have different lytic spectra. The only formal
typing set developed specially for this species is one elaborated mainly for
serotypes 1 and 2 (Meitert et al., 1968). This, though, also differentiates
strains of S. jexneri. There is epidemiological need for a further refined
method for all serotypes of this species.
191
There was no relationship between antigenic type of the phages and their
lytic spectra.
C. Phage sensitivity to physical agents
Phage sensitivity to physical agents generally varies with the p H and
type of suspension medium. Dilute phage suspensions of S. sonneiare
rapidly inactivated, whereas concentrated suspensions with 109-10 11
phages/ml keep for years at + 4°C. A suitable p H for survival appears to be
7.2 (ZieschC and Rische, 1973).
VI. METHOD O F PHAGE TYPING
A. Development of lysotyping
Polyvalent Shigella phages were used early diagnostically to differentiate
Shigella from other enterobacteria (Marcuse, 1931 ; Massa, 1931 ; Sartorius,
1932; Sartorius and Reploh, 1931 ; Sonnenschein, 1925a, b ; Thomen and
Frobisher, 1945). Although the phages are mainly restricted in their action
to shigellae, they may also lyse some E . coli, Enterobacter aerogenoides, E .
cloacae, Salmonella, Arizona, S. dysenteriae, S. jexneri, and Proteus
(Grunow, 1965~). Shigella phages have not lysed Citrobacter or Klebsiella.
Conversely, Shigella has been resistant to even avid phages from Alcalescens,
Proteus, Salmonella, and Aeromonas shigelloides (Rische et al., 1969).
Another interesting diagnostic aspect is the isolation of phage from faeces
to indicate Shigella colonisation of the gut (Hammarstrom, 1949; Grunow
and Kohler, 1965; Wheeler and Burgdorf, 1941).
Phage typing sets have evolved gradually since the early work of Burnet
and McKie (1930) who were the first to demonstrate the fact that phages
produced different lysotypes in Shigella. Burnet in 1933 developed a
typing set for S. jexneri.
Since phages are mostly lytic only for one serogroup, phage typing sets
are specialised for each species in the genus. Methodology is roughly the
same for each species, but there are small, probably coincidental, differences
in recommended techniques for each set. Accordingly, even though they
may work for all sets, the techniques for each one will be described separately.
B. Phage typing of S. dysenteriae
The phages of S. dysenteriae have different lytic spectra. The only formal
typing set developed specially for this species is one elaborated mainly for
serotypes 1 and 2 (Meitert et al., 1968). This, though, also differentiates
strains of S. jexneri. There is epidemiological need for a further refined
method for all serotypes of this species.