3 64
w. B. REDMOND et al.
Leclerc et al. (1971) grew this organism from sewage. Many other attempts
to discover M . kansasii in nature have failed. Wayne (1962) reported two
varieties of M. kansasii according to their catalase activity, with the low
catalase strains being non-pathogenic and the high catalase strains
being pathogens for man. Their observations were confirmed by Gruft
(1972).
The subdivision of the species M . kansasii by phage susceptibility testing
was first reported by Hobby et al. (1967). Engel (1975) phage typed 209
strains of M . kansasii isolated from the Netherlands using 14 phages and
was able to recognise 13 types. Among the organisms tested, 124 were from
Rotterdam and of these 96 showed a single phage type. Only nine strains
of this phage type were clinically significant. However, three of seven and
five of 21 strains of other phage types were human pathogens. No correlation was found between catalase activity and phage type. Thus it appears
that phage typing may permit the subdivision of M . kansasii into two large
groups, one group having a high probability of being a human pathogen
and the second having a high probability of being a saprophyte.
Gunnels and Bates (1972) reported the isolation of three phages useful
for the subdivision of 29 strains of Mycobacterium xenopi into four types,
but the types did not correlate with drug susceptibility, pathogenicity, or
geographic location.
Phage typing and/or subdivision of other species of mycobacteria which
are pathogenic for man such as M. intracellulare and M . scrofulaceum have
not been reported.
V. PRESERVATION AND STORAGE; SHIPPING
A. Bacteriophage
Knowledge of the best methods .and conditions for preservation of phages
and of their bacterial hosts is essential for anyone involved in phage work.
Stocks of phages or bacteria which are unstable require frequent propagation or subculturing. The main properties, such as the plaque morphology
and lytic spectrum of the phages and host range of the bacteria, must be
checked at frequent intervals for each preparation to detect possible
interfering mutations or other changes.
In general, the stability of phages depends on the suspending substrate.
In media containing small amounts of proteins (e.g. bovine serum albumin,
fraction V, or gelatin) or in broth (e.g. nutrient broth, Difco) most mycobacteriophages remain relatively stable (Redmond, 1963). I n salt solutions,
the presence of small amounts (10-3 mol) of divalent cations such as Mg2+
or Ca2+ increases stability (Sellers et al., 1962). Detergents, heavy metals
and other agents may affect the stability of phage suspensions. A good
w. B. REDMOND et al.
Leclerc et al. (1971) grew this organism from sewage. Many other attempts
to discover M . kansasii in nature have failed. Wayne (1962) reported two
varieties of M. kansasii according to their catalase activity, with the low
catalase strains being non-pathogenic and the high catalase strains
being pathogens for man. Their observations were confirmed by Gruft
(1972).
The subdivision of the species M . kansasii by phage susceptibility testing
was first reported by Hobby et al. (1967). Engel (1975) phage typed 209
strains of M . kansasii isolated from the Netherlands using 14 phages and
was able to recognise 13 types. Among the organisms tested, 124 were from
Rotterdam and of these 96 showed a single phage type. Only nine strains
of this phage type were clinically significant. However, three of seven and
five of 21 strains of other phage types were human pathogens. No correlation was found between catalase activity and phage type. Thus it appears
that phage typing may permit the subdivision of M . kansasii into two large
groups, one group having a high probability of being a human pathogen
and the second having a high probability of being a saprophyte.
Gunnels and Bates (1972) reported the isolation of three phages useful
for the subdivision of 29 strains of Mycobacterium xenopi into four types,
but the types did not correlate with drug susceptibility, pathogenicity, or
geographic location.
Phage typing and/or subdivision of other species of mycobacteria which
are pathogenic for man such as M. intracellulare and M . scrofulaceum have
not been reported.
V. PRESERVATION AND STORAGE; SHIPPING
A. Bacteriophage
Knowledge of the best methods .and conditions for preservation of phages
and of their bacterial hosts is essential for anyone involved in phage work.
Stocks of phages or bacteria which are unstable require frequent propagation or subculturing. The main properties, such as the plaque morphology
and lytic spectrum of the phages and host range of the bacteria, must be
checked at frequent intervals for each preparation to detect possible
interfering mutations or other changes.
In general, the stability of phages depends on the suspending substrate.
In media containing small amounts of proteins (e.g. bovine serum albumin,
fraction V, or gelatin) or in broth (e.g. nutrient broth, Difco) most mycobacteriophages remain relatively stable (Redmond, 1963). I n salt solutions,
the presence of small amounts (10-3 mol) of divalent cations such as Mg2+
or Ca2+ increases stability (Sellers et al., 1962). Detergents, heavy metals
and other agents may affect the stability of phage suspensions. A good