12
D. E. MAHONY
In 1953, Sames and McLung isolated eight phages active on C. perfringens, but one of the larger surveys of such bacteriophages is to be found in
the doctoral thesis of Sarnes (1956). This work described the isolation of
33 bacteriophages belonging to three serological groups and four plaque
types. One-step growth curves were described with burst sizes ranging
from 150 to 1900 plaque forming units (pfu).
In 1959, Smithstudied C.perfringens types A, B, C, D, E and F (now considered type C) for lysogeny and found that 12 of 49 strains of type A,
ten of 31 type B and ten of 26 type C and none of 38 type D, five type E or
three type F were lysogenic. The temperate phages attacked only strains of
the same type as that from which they originated. Virulent phages, which
lysed strains belonging to types A, B, C, D and F, were also isolated
although a high proportion of bacterial strains remained resistant to all the
phages isolated. Induction of the lysogenic strains was successful with UV
light, nitrogen mustard and thioglycollate.
GAspAr and Tolnai (1959) performed one of the more informative
characterisations of a virulent C. perfringens phage when they studied one
of GuClin’s phages designated 808/3a. A device was designed in this
experiment for obtaining one-step growth curves of the phage. The phagebacteria culture was constantly agitated with bubbling nitrogen and samples
were moved at various times for plating. A modified Wilson-Blair medium
was employed for plaque counts and a thick overlay of agar containing
phage and bacteria was used to produce anaerobic conditions without the
aid of an anaerobic jar. The latent period of this phage was 45 min and the
burst size,452pfii. Adsorption and immunological experiments were also conducted. I n a second paper (Ghsphr, 1960) describing the effect of aeration
upon phage production, it was shown that aeration of the culture any time
up to 45 min after infection prevented phage multiplication, whereas
aeration at 45 min had no marked effect on phage production. Aeration of
the culture at the time of infection greatly prolonged the latent period, the
lag depending on how long aerobic conditions were maintained. Aeration
was shown to have no adverse effect upon phage viability itself.
Vieu et al. (1965) described a phage which was 70 nm long and had a
polyhedric head 40 nm in diameter and a short tail 30 nm long. The tail
portion possessed a contracted plate 8 nm long and 34 nm in diameter
containing four to seven distinct structures. The tail core which projected
beyond this plate was consistently demonstrated in all preparations.
Ohtomo et al. (1966) described a one-step growth experiment on a phage
of C. perfringens which demonstrated a latent period of 23 min and a
burst size of 140-150 pfu. Oxygen inhibited the multiplication of this phage,
but the inhibition was reversible with the return of anaerobic conditions.
Imamura (1966a, b) surveyed 140 strains of C. perfringens from sewage
D. E. MAHONY
In 1953, Sames and McLung isolated eight phages active on C. perfringens, but one of the larger surveys of such bacteriophages is to be found in
the doctoral thesis of Sarnes (1956). This work described the isolation of
33 bacteriophages belonging to three serological groups and four plaque
types. One-step growth curves were described with burst sizes ranging
from 150 to 1900 plaque forming units (pfu).
In 1959, Smithstudied C.perfringens types A, B, C, D, E and F (now considered type C) for lysogeny and found that 12 of 49 strains of type A,
ten of 31 type B and ten of 26 type C and none of 38 type D, five type E or
three type F were lysogenic. The temperate phages attacked only strains of
the same type as that from which they originated. Virulent phages, which
lysed strains belonging to types A, B, C, D and F, were also isolated
although a high proportion of bacterial strains remained resistant to all the
phages isolated. Induction of the lysogenic strains was successful with UV
light, nitrogen mustard and thioglycollate.
GAspAr and Tolnai (1959) performed one of the more informative
characterisations of a virulent C. perfringens phage when they studied one
of GuClin’s phages designated 808/3a. A device was designed in this
experiment for obtaining one-step growth curves of the phage. The phagebacteria culture was constantly agitated with bubbling nitrogen and samples
were moved at various times for plating. A modified Wilson-Blair medium
was employed for plaque counts and a thick overlay of agar containing
phage and bacteria was used to produce anaerobic conditions without the
aid of an anaerobic jar. The latent period of this phage was 45 min and the
burst size,452pfii. Adsorption and immunological experiments were also conducted. I n a second paper (Ghsphr, 1960) describing the effect of aeration
upon phage production, it was shown that aeration of the culture any time
up to 45 min after infection prevented phage multiplication, whereas
aeration at 45 min had no marked effect on phage production. Aeration of
the culture at the time of infection greatly prolonged the latent period, the
lag depending on how long aerobic conditions were maintained. Aeration
was shown to have no adverse effect upon phage viability itself.
Vieu et al. (1965) described a phage which was 70 nm long and had a
polyhedric head 40 nm in diameter and a short tail 30 nm long. The tail
portion possessed a contracted plate 8 nm long and 34 nm in diameter
containing four to seven distinct structures. The tail core which projected
beyond this plate was consistently demonstrated in all preparations.
Ohtomo et al. (1966) described a one-step growth experiment on a phage
of C. perfringens which demonstrated a latent period of 23 min and a
burst size of 140-150 pfu. Oxygen inhibited the multiplication of this phage,
but the inhibition was reversible with the return of anaerobic conditions.
Imamura (1966a, b) surveyed 140 strains of C. perfringens from sewage